audio recording on IC -help wanted

[gearhead]

On Apr 8, 2:13 pm, Wimpie <wimabc...@tetech.nl> wrote:

On 8 abr, 22:34, gearhead <nos...@billburg.com> wrote:





On Apr 8, 10:03 am, Tim Wescott <t...@seemywebsite.com> wrote:

gearhead wrote:
Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project.  One of them built a
regulator on perfboard and posted the schematic.  It has a couple of
things I'd tweak, but it works.
The main challenge:  his regulator design doesn't incorporate current
limiting.  Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.
Somebody on the forum suggested the zxct1009, but it only comes in
surface mount which means we can't rejigger the existing perfboard
project to include the new chip.  It would mean having a custom-
printed circuit board, and soldering techniques perhaps a little too
demanding for somebody building his first circuit -- which probably
describes a lot of the guys on the forum.
pdf of the circuit:
http://www.hydra-glide.com/phpBB2/download.php?id=1173
I've tried to find a through-hole component that fits the bill, but
can't seem to come up with anything just right.  I saw the micrel
MIC5021, but it supposedly operates on 12 volts and up.
http://www.micrel.com/_PDF/mic5021.pdf
Now, perhaps they make that statement on the datasheet because the
chip actually also has a voltage doubler and the high side drive needs
that kind of voltage to turn on a mosfet, and it's possible the chip
itself will actually run on a much lower voltage.  But the datasheet
doesn't say anything to this effect.  Has anybody used the MIC5021 and
know if it might actually turn on at say 5 volts or perhaps know of
any other through hole chips for current sensing?

This is just a suggestion, but consider the circuit below.  If the
transistors are well matched Vchg should come pretty close to Vgen/10 +
47 * 0.02 * Ibatt -- and you can jigger your component values around to
change the numbers.  You'll _probably_ be able to make this work OK with
any two unmatched (but like part-number) PNP transistors, like 2N3904's,
but you'd do better to get a matched pair (DigiKey has some Zetex parts
that would do, if there are any through-hole ones).

Try this out with SPICE before you run with it: I just threw it down off
the top of my head, it's not exactly like anything I've done before nor
is it tested at all.

      Vgen        ___        Vbatt
       o-----o---|___|---o-----o
             |           |   -----
             |   0.02    |    Ibatt
            .-.         .-.
            | |100      | |100
            | |         | |
            '-'         '-'
             |           |
             |           |
              >|       |
               |---o---|
              /|   |   |\
             |     |     |
             |     |     |
     Vchg    |     '-----o
       o-----o           |
             |           |
            .-.         .-.
            | |4.7K     | |47K
            | |         | |
            '-'         '-'
             |           |
             |           |
            ===         ==> > >             GND         GND

I've done plenty of scheming about how to do it with discretes.  But
like you said, I'd still want to use a chip in the end, to get matched
transistors.  Pairs and arrays, I see ony surface mount, including
zetex.
If I have to go that way, might as well use the ZXCT1009F in SOT-23
with pins 1.9 mm apart according to the diagram.  Almost a tenth of an
inch, could probably solder it right onto the pads of a perfboard, eh?

Hello,

When you buy about 10 general purpose PNP transistors from one batch,
you will probably find several transistors that are within some mV
with same Ic.

Doesn't gain determine the balance in a current mirror? If so, one
would have to match for gain. I did match for gain last time I
experimented with current mirrors. I'd like to hear from the experts
about the need for this.

When you design the 2 transistor current sensor at low
bias current, self heating can be neglected and it saves you from
soldering SMD devices like NXP's BCM857.  When matching is impossible,
you might add a trimmer potentiometer for nulling.

best regards,

Wim
PA3DJSwww.tetech.nl

About temperature matching. I calculate that one tenth of a degree
centigrade difference between the transistors in a mirror would add
about one percent error to the current mirror. I wouldn't want
temperature vagaries causing any more error than that. I'm wondering
if you could count on discrete transistors on a board to stay within a
tenth of a degree to each other. More fodder for the experts.

 

[Wimpie]

On 8 abr, 23:32, gearhead <nos...@billburg.com> wrote:

On Apr 8, 2:13 pm, Wimpie <wimabc...@tetech.nl> wrote:



On 8 abr, 22:34, gearhead <nos...@billburg.com> wrote:

On Apr 8, 10:03 am, Tim Wescott <t...@seemywebsite.com> wrote:

gearhead wrote:
Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project. One of them built a
regulator on perfboard and posted the schematic. It has a couple of
things I'd tweak, but it works.
The main challenge: his regulator design doesn't incorporate current
limiting. Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.
Somebody on the forum suggested the zxct1009, but it only comes in
surface mount which means we can't rejigger the existing perfboard
project to include the new chip. It would mean having a custom-
printed circuit board, and soldering techniques perhaps a little too
demanding for somebody building his first circuit -- which probably
describes a lot of the guys on the forum.
pdf of the circuit:
http://www.hydra-glide.com/phpBB2/download.php?id=1173
I've tried to find a through-hole component that fits the bill, but
can't seem to come up with anything just right. I saw the micrel
MIC5021, but it supposedly operates on 12 volts and up.
http://www.micrel.com/_PDF/mic5021.pdf
Now, perhaps they make that statement on the datasheet because the
chip actually also has a voltage doubler and the high side drive needs
that kind of voltage to turn on a mosfet, and it's possible the chip
itself will actually run on a much lower voltage. But the datasheet
doesn't say anything to this effect. Has anybody used the MIC5021 and
know if it might actually turn on at say 5 volts or perhaps know of
any other through hole chips for current sensing?

This is just a suggestion, but consider the circuit below. If the
transistors are well matched Vchg should come pretty close to Vgen/10 +
47 * 0.02 * Ibatt -- and you can jigger your component values around to
change the numbers. You'll _probably_ be able to make this work OK with
any two unmatched (but like part-number) PNP transistors, like 2N3904's,
but you'd do better to get a matched pair (DigiKey has some Zetex parts
that would do, if there are any through-hole ones).

Try this out with SPICE before you run with it: I just threw it down off
the top of my head, it's not exactly like anything I've done before nor
is it tested at all.

Vgen ___ Vbatt
o-----o---|___|---o-----o
| | -----
| 0.02 | Ibatt
.-. .-.
| |100 | |100
| | | |
'-' '-'
| |
| |
| |
|---o---|
/| | |\
| | |
| | |
Vchg | '-----o
o-----o |
| |
.-. .-.
| |4.7K | |47K
| | | |
'-' '-'
| |
| |
=== ===
GND GND

I've done plenty of scheming about how to do it with discretes. But
like you said, I'd still want to use a chip in the end, to get matched
transistors. Pairs and arrays, I see ony surface mount, including
zetex.
If I have to go that way, might as well use the ZXCT1009F in SOT-23
with pins 1.9 mm apart according to the diagram. Almost a tenth of an
inch, could probably solder it right onto the pads of a perfboard, eh?

Hello,

When you buy about 10 general purpose PNP transistors from one batch,
you will probably find several transistors that are within some mV
with same Ic.

Doesn't gain determine the balance in a current mirror? If so, one
would have to match for gain. I did match for gain last time I
experimented with current mirrors. I'd like to hear from the experts
about the need for this.

When you design the 2 transistor current sensor at low
bias current, self heating can be neglected and it saves you from
soldering SMD devices like NXP's BCM857. When matching is impossible,
you might add a trimmer potentiometer for nulling.

best regards,

Wim
PA3DJSwww.tetech.nl

About temperature matching. I calculate that one tenth of a degree
centigrade difference between the transistors in a mirror would add
about one percent error to the current mirror. I wouldn't want
temperature vagaries causing any more error than that. I'm wondering
if you could count on discrete transistors on a board to stay within a
tenth of a degree to each other. More fodder for the experts.

Hello,

For such circuits matching on Vbe with constant collector current is
sufficient. I normally do it by connecting B to C, bias at required
current and measure the voltage across the diode. Of course for high
volume applications I use a matched pair.

When 1% additional tolerance is unacceptable, you also should evaluate
all other components. I think of current sensing resistor, other
resistors, voltage variatons, offsets in control loop etc. Regarding
temperature, put them close together, take some epoxy resin and some
piece of coper/alu, and temperature difference due to environment will
be negligible.

I can hardly imagine that your original application requires that high
accuracy. Last year I designed several current limiting circuits for
hot swap applications and inrush current limiting and less then 5%
accuracy without adjustment and cheap components will be very
difficult.

Best regards,

Wim
PA3DJS
www.tetech.nl
please remove abc from the address.

 

[petrus bitbyter]

"gearhead" <nospam@billburg.com> schreef in bericht
news:7226e6a4-ddd0-4da5-807a-5799069d795d@k13g2000hse.googlegroups.com...
On Apr 8, 1:30 pm, "petrus bitbyter"
<pieterkraltlaatdit...@enditookhccnet.nl> wrote:

"gearhead" <nos...@billburg.com> schreef in
berichtnews:e66fa9e8-d621-4ba3-8c47-fc5752b3f045@m36g2000hse.googlegroups.com...





Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project. One of them built a
regulator on perfboard and posted the schematic. It has a couple of
things I'd tweak, but it works.
The main challenge: his regulator design doesn't incorporate current
limiting. Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.
Somebody on the forum suggested the zxct1009, but it only comes in
surface mount which means we can't rejigger the existing perfboard
project to include the new chip. It would mean having a custom-
printed circuit board, and soldering techniques perhaps a little too
demanding for somebody building his first circuit -- which probably
describes a lot of the guys on the forum.
pdf of the circuit:
http://www.hydra-glide.com/phpBB2/download.php?id=1173
I've tried to find a through-hole component that fits the bill, but
can't seem to come up with anything just right. I saw the micrel
MIC5021, but it supposedly operates on 12 volts and up.
http://www.micrel.com/_PDF/mic5021.pdf
Now, perhaps they make that statement on the datasheet because the
chip actually also has a voltage doubler and the high side drive needs
that kind of voltage to turn on a mosfet, and it's possible the chip
itself will actually run on a much lower voltage. But the datasheet
doesn't say anything to this effect. Has anybody used the MIC5021 and
know if it might actually turn on at say 5 volts or perhaps know of
any other through hole chips for current sensing?

That Micrel chip is not a current sensor, it is a mosfet driver. Looking
for
a highside current sensor, try the MAX4374. A ZXCT1008 or ZXCT1009 may be
even better. But I doubt you to need that special (and expensive) chips.

Can't be sure what current you want to limit, but usually the field
current
is limited to limit the output voltage of the generator. Which in turn
prevents the battery from being overloaded. This is exactly what the
circuit
of your schematic is supposed to do. Just use R1 to set the correct
voltage.
For a 6V lead-accid battery this will be about 6,9V. So even for fully
loaded battery the voltage should never exceed that value. You may have to
take some voltage loss accross D6 into account which is about 0.2V for
this
particular diode.

petrus bitbyter- Hide quoted text -

- Show quoted text -

| Don't say the micrel chip is not a current sensor. It does current
| sensing.
| And current limiting is for the generator, not the battery.

Hmm... Did you check the high-side current sensors I mentioned? As you know
the datasheet of the mic5021 can you explain how you get a signal from it
that is proportional to the measured current? I don't see it, but I like to
learn.

I am not aware of an automotive generator with a current limiter other then
the fields. Normaly the generator is big enough to provide the required
power for the vehicles appliances with a wide margin but yes, you can damage
it by overloading it. Most of the times however you will blow one or more
fuses when you try.

petrus bitbyter

 

[gearhead]

On Apr 8, 5:59 pm, "petrus bitbyter"
<pieterkraltlaatdit...@enditookhccnet.nl> wrote:

"gearhead" <nos...@billburg.com> schreef in berichtnews:7226e6a4-ddd0-4da5-807a-5799069d795d@k13g2000hse.googlegroups.com...
On Apr 8, 1:30 pm, "petrus bitbyter"





pieterkraltlaatdit...@enditookhccnet.nl> wrote:
"gearhead" <nos...@billburg.com> schreef in
berichtnews:e66fa9e8-d621-4ba3-8c47-fc5752b3f045@m36g2000hse.googlegroups.com...

Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project. One of them built a
regulator on perfboard and posted the schematic. It has a couple of
things I'd tweak, but it works.
The main challenge: his regulator design doesn't incorporate current
limiting. Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.
Somebody on the forum suggested the zxct1009, but it only comes in
surface mount which means we can't rejigger the existing perfboard
project to include the new chip. It would mean having a custom-
printed circuit board, and soldering techniques perhaps a little too
demanding for somebody building his first circuit -- which probably
describes a lot of the guys on the forum.
pdf of the circuit:
http://www.hydra-glide.com/phpBB2/download.php?id=1173
I've tried to find a through-hole component that fits the bill, but
can't seem to come up with anything just right. I saw the micrel
MIC5021, but it supposedly operates on 12 volts and up.
http://www.micrel.com/_PDF/mic5021.pdf
Now, perhaps they make that statement on the datasheet because the
chip actually also has a voltage doubler and the high side drive needs
that kind of voltage to turn on a mosfet, and it's possible the chip
itself will actually run on a much lower voltage. But the datasheet
doesn't say anything to this effect. Has anybody used the MIC5021 and
know if it might actually turn on at say 5 volts or perhaps know of
any other through hole chips for current sensing?

That Micrel chip is not a current sensor, it is a mosfet driver. Looking
for
a highside current sensor, try the MAX4374. A ZXCT1008 or ZXCT1009 may be
even better. But I doubt you to need that special (and expensive) chips.

Can't be sure what current you want to limit, but usually the field
current
is limited to limit the output voltage of the generator. Which in turn
prevents the battery from being overloaded. This is exactly what the
circuit
of your schematic is supposed to do. Just use R1 to set the correct
voltage.
For a 6V lead-accid battery this will be about 6,9V. So even for fully
loaded battery the voltage should never exceed that value. You may have to
take some voltage loss accross D6 into account which is about 0.2V for
this
particular diode.

petrus bitbyter- Hide quoted text -

- Show quoted text -

| Don't say the micrel chip is not a current sensor.  It does current
| sensing.
| And current limiting is for the generator, not the battery.

Hmm... Did you check the high-side current sensors I mentioned? As you know
the datasheet of the mic5021 can you explain how you get a signal from it
that is proportional to the measured current? I don't see it, but I like to
learn.

The MIC5021 does not put out a proportional signal, it trips at 50mV.
Yes, maybe it would make the lights flicker if it were to toggle on
and off too slowly. And I looked at the sensors you mentioned, okay?

I am not aware of an automotive generator with a current limiter other then
the fields. Normaly the generator is big enough to provide the required
power for the vehicles appliances with a wide margin but yes, you can damage
it by overloading it. Most of the times however you will blow one or more
fuses when you try.

petrus bitbyter- Hide quoted text -

- Show quoted text -

You need to know, this isn't an alernator. Are you familiar with the
old-fashioned generators with the long, skinny armatures with
segmented commutators? They are different from modern alternators in
that they will burn themselves up if you overload them.
Is English a second language for you?

 

[gearhead]

On Apr 8, 3:53 pm, Wimpie <wimabc...@tetech.nl> wrote:

On 8 abr, 23:32, gearhead <nos...@billburg.com> wrote:





On Apr 8, 2:13 pm, Wimpie <wimabc...@tetech.nl> wrote:

On 8 abr, 22:34, gearhead <nos...@billburg.com> wrote:

On Apr 8, 10:03 am, Tim Wescott <t...@seemywebsite.com> wrote:

gearhead wrote:
Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project.  One of them built a
regulator on perfboard and posted the schematic.  It has a couple of
things I'd tweak, but it works.
The main challenge:  his regulator design doesn't incorporate current
limiting.  Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.
Somebody on the forum suggested the zxct1009, but it only comes in
surface mount which means we can't rejigger the existing perfboard
project to include the new chip.  It would mean having a custom-
printed circuit board, and soldering techniques perhaps a little too
demanding for somebody building his first circuit -- which probably
describes a lot of the guys on the forum.
pdf of the circuit:
http://www.hydra-glide.com/phpBB2/download.php?id=1173
I've tried to find a through-hole component that fits the bill, but
can't seem to come up with anything just right.  I saw the micrel
MIC5021, but it supposedly operates on 12 volts and up.
http://www.micrel.com/_PDF/mic5021.pdf
Now, perhaps they make that statement on the datasheet because the
chip actually also has a voltage doubler and the high side drive needs
that kind of voltage to turn on a mosfet, and it's possible the chip
itself will actually run on a much lower voltage.  But the datasheet
doesn't say anything to this effect.  Has anybody used the MIC5021 and
know if it might actually turn on at say 5 volts or perhaps know of
any other through hole chips for current sensing?

This is just a suggestion, but consider the circuit below.  If the
transistors are well matched Vchg should come pretty close to Vgen/10 +
47 * 0.02 * Ibatt -- and you can jigger your component values around to
change the numbers.  You'll _probably_ be able to make this work OK with
any two unmatched (but like part-number) PNP transistors, like 2N3904's,
but you'd do better to get a matched pair (DigiKey has some Zetex parts
that would do, if there are any through-hole ones).

Try this out with SPICE before you run with it: I just threw it down off
the top of my head, it's not exactly like anything I've done before nor
is it tested at all.

      Vgen        ___        Vbatt
       o-----o---|___|---o-----o
             |           |   -----
             |   0.02    |    Ibatt
            .-.         .-.
            | |100      | |100
            | |         | |
            '-'         '-'
             |           |
             |           |
              >|       |
               |---o---|
              /|   |   |\
             |     |     |
             |     |     |
     Vchg    |     '-----o
       o-----o           |
             |           |
            .-.         .-.
            | |4.7K     | |47K
            | |         | |
            '-'         '-'
             |           |
             |           |
            ===         ==> > > > >             GND         GND

I've done plenty of scheming about how to do it with discretes.  But
like you said, I'd still want to use a chip in the end, to get matched
transistors.  Pairs and arrays, I see ony surface mount, including
zetex.
If I have to go that way, might as well use the ZXCT1009F in SOT-23
with pins 1.9 mm apart according to the diagram.  Almost a tenth of an
inch, could probably solder it right onto the pads of a perfboard, eh?

Hello,

When you buy about 10 general purpose PNP transistors from one batch,
you will probably find several transistors that are within some mV
with same Ic.

Doesn't gain determine the balance in a current mirror?  If so, one
would have to match for gain.  I did match for gain last time I
experimented with current mirrors.  I'd like to hear from the experts
about the need for this.

When you design the 2 transistor current sensor at low
bias current, self heating can be neglected and it saves you from
soldering SMD devices like NXP's BCM857.  When matching is impossible,
you might add a trimmer potentiometer for nulling.

best regards,

Wim
PA3DJSwww.tetech.nl

About temperature matching.  I calculate that one tenth of a  degree
centigrade difference between the transistors in a mirror would add
about one percent error to the current mirror.  I wouldn't want
temperature vagaries causing any more error than that.  I'm wondering
if you could count on discrete transistors on a board to stay within a
tenth of a degree to each other.  More fodder for the experts.

Hello,

For such circuits matching on Vbe with constant collector current is
sufficient. I normally do it by connecting B to C, bias at required
current and measure the voltage across the diode.  Of course for high
volume applications I use a matched pair.

When 1% additional tolerance is unacceptable, you also should evaluate
all other components. I think of current sensing  resistor, other
resistors, voltage variatons, offsets in control loop etc. Regarding
temperature, put them close together, take some epoxy resin and some
piece of coper/alu, and temperature difference due to environment will
be negligible.

I can hardly imagine that your original application requires that high
accuracy.   Last year I designed several current limiting circuits for
hot swap applications and inrush current limiting and less then 5%
accuracy without adjustment and cheap components will be very
difficult.

Best regards,

Wim
PA3DJSwww.tetech.nl
please remove abc from the address.- Hide quoted text -

- Show quoted text -

My first dog was named Wimpie.
And there was a Wimpie character in the old Popeye comic that used to
say,
"I will gladly pay you Thursday for a hamburger today!"
Ah, Saturday mornings in front of the TV.

Thanks for the tip about testing Vbe, it makes sense. I guess putting
a bunch of diode-connected transistors in series would really be the
best way, you could go down the line testing voltage and sort them out
right quick.

73 de KF2HI

 

[Scott Seidman]

gearhead <nospam@billburg.com> wrote in news:e66fa9e8-d621-4ba3-8c47-
fc5752b3f045@m36g2000hse.googlegroups.com:

if it might actually turn on at say 5 volts or perhaps know of
any other through hole chips for current sensing?

I'd pick up a surfboard and give up on the thruhole idea.

--
Scott
Reverse name to reply

 

[petrus bitbyter]

"gearhead" <nospam@billburg.com> schreef in bericht
news:b694b51d-ac34-4e3b-9886-18e95b7ea735@e39g2000hsf.googlegroups.com...
On Apr 8, 5:59 pm, "petrus bitbyter"
<pieterkraltlaatdit...@enditookhccnet.nl> wrote:

"gearhead" <nos...@billburg.com> schreef in
berichtnews:7226e6a4-ddd0-4da5-807a-5799069d795d@k13g2000hse.googlegroups.com...
On Apr 8, 1:30 pm, "petrus bitbyter"





pieterkraltlaatdit...@enditookhccnet.nl> wrote:
"gearhead" <nos...@billburg.com> schreef in
berichtnews:e66fa9e8-d621-4ba3-8c47-fc5752b3f045@m36g2000hse.googlegroups.com...

Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project. One of them built a
regulator on perfboard and posted the schematic. It has a couple of
things I'd tweak, but it works.
The main challenge: his regulator design doesn't incorporate current
limiting. Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.
Somebody on the forum suggested the zxct1009, but it only comes in
surface mount which means we can't rejigger the existing perfboard
project to include the new chip. It would mean having a custom-
printed circuit board, and soldering techniques perhaps a little too
demanding for somebody building his first circuit -- which probably
describes a lot of the guys on the forum.
pdf of the circuit:
http://www.hydra-glide.com/phpBB2/download.php?id=1173
I've tried to find a through-hole component that fits the bill, but
can't seem to come up with anything just right. I saw the micrel
MIC5021, but it supposedly operates on 12 volts and up.
http://www.micrel.com/_PDF/mic5021.pdf
Now, perhaps they make that statement on the datasheet because the
chip actually also has a voltage doubler and the high side drive needs
that kind of voltage to turn on a mosfet, and it's possible the chip
itself will actually run on a much lower voltage. But the datasheet
doesn't say anything to this effect. Has anybody used the MIC5021 and
know if it might actually turn on at say 5 volts or perhaps know of
any other through hole chips for current sensing?

That Micrel chip is not a current sensor, it is a mosfet driver. Looking
for
a highside current sensor, try the MAX4374. A ZXCT1008 or ZXCT1009 may
be
even better. But I doubt you to need that special (and expensive) chips.

Can't be sure what current you want to limit, but usually the field
current
is limited to limit the output voltage of the generator. Which in turn
prevents the battery from being overloaded. This is exactly what the
circuit
of your schematic is supposed to do. Just use R1 to set the correct
voltage.
For a 6V lead-accid battery this will be about 6,9V. So even for fully
loaded battery the voltage should never exceed that value. You may have
to
take some voltage loss accross D6 into account which is about 0.2V for
this
particular diode.

petrus bitbyter- Hide quoted text -

- Show quoted text -

| Don't say the micrel chip is not a current sensor. It does current
| sensing.
| And current limiting is for the generator, not the battery.

Hmm... Did you check the high-side current sensors I mentioned? As you
know
the datasheet of the mic5021 can you explain how you get a signal from it
that is proportional to the measured current? I don't see it, but I like
to
learn.
|

| The MIC5021 does not put out a proportional signal, it trips at 50mV.
| Yes, maybe it would make the lights flicker if it were to toggle on
| and off too slowly. And I looked at the sensors you mentioned, okay?

I am not aware of an automotive generator with a current limiter other
then
the fields. Normaly the generator is big enough to provide the required
power for the vehicles appliances with a wide margin but yes, you can
damage
it by overloading it. Most of the times however you will blow one or more
fuses when you try.

petrus bitbyter- Hide quoted text -

- Show quoted text -
|

| You need to know, this isn't an alernator. Are you familiar with the
| old-fashioned generators with the long, skinny armatures with
| segmented commutators? They are different from modern alternators in
| that they will burn themselves up if you overload them.
| Is English a second language for you?

I remember those old things and the electromecanical circuits that
controlled them, though I never got into their inner workings. So I do not
know about current control and how it was done.

English is not my native tongue.

Consider a ZDX1009. It is SMD but large enough to be mounted on perf board.
The datasheet shows the internal schematic which is very simple so you can
also build it using discretes. You have to use matched transistors as others
stated already.

petrus bitbyter

 

jeans:
cheap EVISU jeans wholesale www.king-trade.cn
cheap ED hardy jeans wholesale
cheap COOGI jeans wholesale www.king-trade.cn
cheap GINO GREEN GLOBAL jeans wholesale
cheap LACOSTE jeans wholesale
cheap G-STAR jeans wholesale
cheap KED ROBOT jeans wholesale
cheap RED MONKEY jeans wholesale
cheap ADIDAS jeans wholesale
cheap BBC jeans wholesale www.king-trade.cn
cheap BOSS jeans wholesale
cheap LRG jeans wholesale www.king-trade.cn
cheap HELEN jeans wholesale
cheap JUICY jeans wholesale
cheap THE CROUN HOLDER jeans wholesale
cheap SMET jeans wholesale
cheap SEVEN jeans wholesale www.king-trade.cn
cheap TRUN NORTH FACE jeans wholesale
cheap children jeans wholesale
cheap ARMANI jeans wholesale www.king-trade.cn
cheap BAPE jeans wholesale
cheap LEVIS jeans wholesale
cheap ANTIK jeans wholesale www.king-trade.cn
cheap true religion jeans wholesale

 

[Arfa Daily]

"Sally" <me@anon.net> wrote in message news:469a8679@dnews.tpgi.com.au...

Without taking sides on any other issues, IMO the old rule not to top post
is out of date! It is much more appropriate in today's environment to top
post.

Not on Usenet ...

Arfa

 

[gearhead]

Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project. One of them built a
regulator on perfboard and posted the schematic. It has a couple of
things I'd tweak, but it works.
The main challenge: his regulator design doesn't incorporate current
limiting. Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.

(snip)

I remember those old things and the electromecanical circuits that
controlled them, though I never got into their inner workings. So I do not
know about current control and how it was done.

English is not my native tongue.

Consider a ZDX1009. It is SMD but large enough to be mounted on perf board.
The datasheet shows the internal schematic which is very simple so you can
also build it using discretes. You have to use matched transistors as others
stated already.

petrus bitbyter

You mean the ZDS1009, petrus.
Check out that circuit in the datasheet -- if it doesn't leak, it
won't turn on.
The circuit below shouldn't have any problem starting up.
Below Ilimit, the collector output will not source any current. Just
as load current passes Ilimit the output collector should start
sourcing a small current. I can use this collector current in a
feedback loop with the voltage regulator and make the load current
settle at Ilimit.



V+----+-----Rs-------+-----+---load
| | |
Re | |
| | |
| | |
\ PN2907 / |

| x2 |< |
|---+----| |

/| | |\ |
/ | \ |
| | | |
+------' | /
| | |<
| ,-------+--|
| | | |
\ | / \
\| | |/ \
|---+----| '---out
/| |\
< PN2222x2 >
| |
'------+-------'
|
current sink
I = 2 Ilimit Rs / Re
|
|
gnd

For example, Isink = 200 uA, Re = 1k, Rs = .01, Ilimit = 10 A
The current mirrors reach an equilibrium at Ilimit, with 100 uA on
each side.
Below Ilimit, the right side of the current mirror pulls up and the
left side pulls down. The output transistor stays turned off.
Above Ilimit, the left side pulls up and the ride side pulls down,
drawing some current from the base of the output transistor.

Whaddya think, it might work?

 

[Tim Williams]

LM360 is blinding fast TTL. Single per package and gobs of current, so not
exactly just "a little" quicker.

LM319 as mentioned is about inbetween the 393 and 360. IIRC, the 319 comes
in single units as well.

Tim

--
Deep Fryer: A very philosophical monk.
Website @ http://webpages.charter.net/dawill/tmoranwms

"Eeyore" <rabbitsfriendsandrelations@hotmail.com> wrote in message
news:473F4AC0.4A8072DC@hotmail.com...

Looking for an inexpensive commodity dual comparator that's a little
quicker
than the ubiquitous LM393.

Suggestions ?

Graham

 

[gearhead]

On Apr 9, 4:09 pm, gearhead <nos...@billburg.com> wrote:

Hi all, I'd like to help out some friends on an antique motorcycle
forum that have a 6 volt regulator project. One of them built a
regulator on perfboard and posted the schematic. It has a couple of
things I'd tweak, but it works.
The main challenge: his regulator design doesn't incorporate current
limiting. Even the original relay-style mechanical regulators
incorporated current limiting, because the generators required it.

(snip)



I remember those old things and the electromecanical circuits that
controlled them, though I never got into their inner workings. So I do not
know about current control and how it was done.

English is not my native tongue.

Consider a ZDX1009. It is SMD but large enough to be mounted on perf board.
The datasheet shows the internal schematic which is very simple so you can
also build it using discretes. You have to use matched transistors as others
stated already.

petrus bitbyter

You mean the ZDS1009, petrus.
Check out that circuit in the datasheet -- if it doesn't leak, it
won't turn on.
The circuit below shouldn't have any problem starting up.
Below Ilimit, the collector output will not source any current.  Just
as load current passes Ilimit the output collector should start
sourcing a small current.  I can use this collector current in a
feedback loop with the voltage regulator and make the load current
settle at Ilimit.

 V+----+-----Rs-------+-----+---load
       |              |     |
       Re             |     |
       |              |     |
       |              |     |
        \   PN2907   /      |
         >|   x2   |<       |
          |---+----|        |
         /|   |    |\       |
        /     |      \      |
       |      |       |     |
       +------'       |    /
       |              |  |
       |      ,-------+--|
       |      |       |  |
        \     |      /    \
         \|   |    |/      \
          |---+----|        '---out
         /|        |\
        <  PN2222x2  
       |              |
       '------+-------'
              |
         current sink
     I = 2 Ilimit Rs / Re
              |
              |
             gnd

For example, Isink = 200 uA, Re = 1k, Rs = .01, Ilimit = 10 A
The current mirrors reach an equilibrium at Ilimit, with 100 uA on
each side.
Below Ilimit, the right side of the current mirror pulls up and the
left side pulls down.  The output transistor stays turned off.
Above Ilimit, the left side pulls up and the ride side pulls down,
drawing some current from the base of the output transistor.

Correction: instead of a mirror it needs separate current sinks on

the ground in order to work.

V+----+-----Rs-------+-----+---load
| | |
Re | |
| | |
| | |
\ PN2907 / |
| x2 |< |
|---+----| |
/| | |\ |
/ | \ |
| | | |
+------' | /
| | |
| +--|
| | |
| | \
| | \
Isink = 100uA = Isink '---out
| |
'------+-------'
|
gnd

And another transistor on the output for more gain, if necessary.

 

--------------------------------------------------------------------------------

PA2487, PA2487U, PA2487UG, PA2487UR Laptop Battery
Replacement for TOSHIBA Satellite 200, 210CDT, 430, 1830 / Dynabook
T2, T3, T4, T5, T6 Series / Dynabook Satellite 1800 Series... Product
Type:TOSHIBA Laptop BatteryProduct Price :USD$89.96Details:
PA2505, PA2505UR, PA2506UR Laptop Battery
Replacement for TOSHIBA Portege 7000, 7010, 7020, 7140, 7200, 7220
Series Laptop Battery... Product Type:TOSHIBA Laptop BatteryProduct
Price :USD$75.97Details:
PA2510, PA2510U, PA2510UR Laptop Battery
Replacement for TOSHIBA Tecra 8000 Series Laptop Battery... Product
Type:TOSHIBA Laptop BatteryProduct Price :USD$72.95Details:
PA2522U, PA2522U-1BAS, PA2522U-1BRS Laptop Battery
Replacement for TOSHIBA Satellite 2450, 2455 Series / Satellite A20-
S103 Laptop Battery... Product Type:TOSHIBA Laptop BatteryProduct
Price :USD$96.98Details:
PA3001, PA3001U-1BRM, PA3002U-1BRL Laptop Battery
Replacement for TOSHIBA Portege 7000, 7010, 7020, 7140, 7200, 7220
Series (High Capacity) Laptop Battery... Product Type:TOSHIBA Laptop
BatteryProduct Price :USD$81.90Details:
PA3009, PA3009U, PA3009U-1BAR Laptop Battery
Replacement for TOSHIBA Tecra 8100 Series Laptop Battery... Product
Type:TOSHIBA Laptop BatteryProduct Price :USD$79.98Details:
PA3031, PA3031U, PA3031U-1BAS Laptop Battery
Replacement for TOSHIBA Satellite 1600 Series Laptop Battery...
Product Type:TOSHIBA Laptop BatteryProduct Price :USD$70.98Details:
PA3098, PA3098U, PA3098U-1BAS, PA3098U-1BRS Laptop Battery
Replacement for TOSHIBA Satellite 1200, 3000, 3005 Series Laptop
Battery... Product Type:TOSHIBA Laptop BatteryProduct Price :USD
$79.99Details: << Previous Next >>

 

[Joerg]

David DiGiacomo wrote:

In article <p3TIj.4014$p24.3690@nlpi061.nbdc.sbc.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:
I usually need more extreme tap ratios (or impedance ratios). But even
these 3.58MHz will likely go lalaland soon because analog TV is gone for
good in the US next year. It's going to be a 100% cut, there won't be
any analog stations left by the end of February. Meaning no chroma
carriers either.

Not true, there will still be LPTV and analog cable... not to mention
Canada, Mexico, etc. Also, parts that are useful in ATSC to NTSC
converter boxes will be popular for a while longer.

Right, but the sets will most likely do all this in a baseband DSP
setting. The ATSC to NTSC modulators won't have LC, just a 3.58MHz
crystal. Maybe not even that if they contain a modulator and generate it
from another reference. Last time at CostCo it seemed the regular sets
have already gone extinct, all flat screens.

The converter coupons arrived yesterday BTW. However, so far it looks
like OTA DTV isn't going to very reliable out here, pretty much as I had
expected :-(

--
Regards, Joerg

http://www.analogconsultants.com/

"gmail" domain blocked because of excessive spam.
Use another domain or send PM.

 

[Michael A. Terrell]

Kris Wilk wrote:

On Apr 9, 4:18 pm, JeffM <jef...@email.com> wrote:
Neither of the groups to which you posted this is a buy-and-sell
group.
You would know this if you bothered to actually READ either of the
groups.

It is also stated explicitly in the charter.http://groups.google.com/group/sci.electronics/msg/13651a897337a7a9?q...

You have just labelel yourself and your company as SPAMMERS.

Jeff,

I read both sci.electronics.components and sci.electronics.design.
What I see is that they are being polluted by spam. Spam like "Top
Quality Rolex...." and "Good quality versace shoes...".

Dump Google Groups and subscribe to a real NTTP news server. If yo
take a look at that spam you will see that it being posted through
Google groups, so you are aiding and abetting the spammers by letting
Google make money from their sponsored ads.

What I also
see on a regular basis are your futile attempts to stop the influx of
this garbage by posting replies it. In the process you are aggravating
me and I would venture to say most other readers by further reducing
the signal-to-noise ratio here.

Which is why most of the regulars are filtering out all traffic from
Google Groups.

Replying to an automated spambot will
do nothing...except reinforce to the spammer that their message is
being seen.

My message was perfectly innocent and relevant. I have some unused
components and wanted to offer them up to my friends here for next to
nothing. I almost threw them away, but figured someone might be able
to use them. A quick look at my posting history will show that I don't
make a business of selling chips in usenet.

Honestly, if not in "sci.electronics.components", in which newsgroup
would it have been more appropriate to offer electronic components?

In the newsgroup that was create for selling electronic components
and test equipment: news:misc.industry.electronics.marketplace


--
aioe.org is home to cowards and terrorists

Add this line to your news proxy nfilter.dat file
* drop Path:*aioe.org!not-for-mail to drop all aioe.org traffic.

http://improve-usenet.org/index.html


Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM

 

[test equipment buyer]

Test equipment needed, please quote , used with deep discounts
prefered
QTY 1 each

Agilent 8922F
IFR 1500S
Agilent 8163a
Agilent 81633a
Agilent 81618a
Agilent 81623a
Agilent 8703b
Keithley 2400

Kind Regards,
Ben Youngblood

http://www.networkinghardware.net

DCR is your one stop solution for Datacom, Networking & Telecom
hardware, new and used at 60% to 90% off list.

We buy & sell 3com, ADC/Kentrox, Adtran, Ascend/Lucent, AVAYA,
Cisco, Enterasys/Cabletron, Extreme, JUNIPER NETWORKS, Larscom,
Lucent PSAX, N.E.T. Promina & IDNX, Nortel, Cisco/Stratacom,
Newbridge,
Verilink, Nortel Networks, TELLABS and more...

Over 5,000 items in stock. Please visit out our website @

http://www.networkinghardware.net

SOME INVENTORY ON-LINE. PLEASE CALL
OR REPLY FOR UPDATED OR INCOMING INVENTORY

posted by Benny Youngblood

please quote by Ben "Benny Youngblood networkinghardware.net
http://www.networkinghardware.net test equipment needed, please quote
by Ben "Benny Youngblood networkinghardware.net http://www.networkinghardware.net

 

[sr]

I'm looking for a data level translator chip to connect a 5V mcu to a
3.3V radio modem. The ideal chip should provide full 4 way level
translation for rxd,txd,rts and cts signals with no external parts (sort
of a 4x MAX3370). A double 2 way arrangement using two chips would be
still ok though.
Speed and price are not a problem: the data rate will never exceed 38.4
kbps and I'll need only a dozen of these beasts for now; my only
requirement is the DIP package: being still not skilled/equipped for SMD
soldering I'm forced to go for a stone age old DIP part, which makes it
harder to find.
Could anyone suggest some chips with these features? Thanks!

 

[JeffM]

JeffM wrote:
Neither of the groups to which you posted this
is a buy-and-sell group.
You would know this
if you bothered to actually READ either of the groups.
[...]
You have just [labeled] yourself and your company as SPAMMERS.

Kris Wilk wrote:
I read both sci.electronics.components and sci.electronics.design.

In that case, your ability to perceive patterns is severely lacking.

What I see is that they are being polluted by spam.

....so, having YOU adding to it is suddenly acceptable?

....as well as adding to the perception of *It's OK to spam here*.

Spam like "Top Quality Rolex...." and "Good quality versace shoes...".

I expect more of people who read s.e.d than *Monkey see, monkey do*.

your futile attempts to stop the influx of this garbage
by posting replies it.
[. . .]Replying to an automated spambot[...]

1) Most of what you think are bots are low-wage humans.

2) Got an example of me replying to one of these
that isn't trying to hawk something ostensibly related to electronics
pros?

As in *this* case, I try to choose my targets carefully.
YOUR unwillingness to heed the admonitions is the issue here
--especially after having acknowledged that you have read them.

My message was perfectly innocent and relevant.

If you actually HAD been reading the groups,

the patterns of posts being made would tell you that is CRAP.
When ads for the buying and selling of ostensibly-on-topic stuff
appears in the sci.* hierarchy, those are chastised.
Even a casual reader of the groups knows that.
Again: The problem is YOUR inability to perceive patterns.

Kris Wilk wrote:
espite disagreeing with your characterization of me and my company
:
I call 'em like I see 'em.
If you don't want to be lumped together with certain people,
don't ACT like those people.

Honestly, if not in "sci.electronics.components", in which newsgroup
would it have been more appropriate to offer electronic components?

You finally clicked my link

http://groups.google.com/group/sci.electronics/msg/13651a897337a7a9?q=Charters+misc.industry.electronics.marketplace+Discussions+Advertisement-*-*+only.advertise+*-design-of-*-circuits+sci.electronics.design-*-*-design+combining.components.into.circuits+the.rec.hierarchy+*.*.not.a.forsale.group+zz-zz+Discussion
and answered the question for yourself.

Some Usenet history: (NO ADS is the rule--NOT the exception)
http://groups.google.com/group/sci.electronics.components/browse_frm/thread/a016359c368157dd/68434e5260ed7821?q=when-*-*-*-*-*-created+*-doesn't-mean-*-*-*+at.a.higher.level.than.a.*.charter+no-*+qq+*.had.no.reason.to.*.mention.*+*-*-*-find-out-about-Usenet+*-*-antisocial-one+*-*-stumble-*-*-*-*-*-*

**How NOT to Advertise on Usenet by Joel K. Furr**
http://www.google.com/search?q=cache:W6rxVAYEMg8J:www.use-net.ch/advo_engl.html+rude.to.advertise.*.*+*-*-*-*-*-*-the-word-forsale-or-marketplace-in-their-names+preserve.*.culture.of.open.discussion+reads.*.advertisement+pays+*.most.pervasive.form.*.*.*.*-*+How-*-to-Advertise-on-Usenet+biz+hated+rude+lose-*-account
..
..
As Terrell noted, Google Groupers get a distorted picture of Usenet.
Your inability to mentally filter out junk exacerbates the condition.

Perhaps you should look into Damian Penney's Google Groups Plus
or David Rice's Google Groups Filter at holysmoke.org
or Mark Meulendyk's TrollKiller.
http://groups.google.com/group/sci.electronics.repair/browse_frm/thread/45c21143c598ed41/46529731e2e29c45?q=*-Meulendyk+holysmoke+*-Penney

....or as Mike suggested, get a real newsreader/provider.

 

[Michael Black]

On Thu, 10 Apr 2008, jusme wrote:

Ross, You are a trouble-maker.

I came here asking for a transistor. You and a few others piped up saying
that it is proprietary. I know that it is not proprietary and you demanded
to know how I know that. Well, if you had more experience and knowledge in
this field, you would know that, too.

Now, you can continue to demand this or that, make trouble and issue forth
sarcasm. However, you won't get any education from me.

If you read from the beginning, I have been courteous right up to the point
that you tuned up.

You assume much. You assume that I don't have the datasheet.

From your original message:

or equivalent. I only need one but would like to have
some spares.

I have looked all over. I would even take a datasheet.

We never assumed, you told us.

You've fallen into the common error, that of people thinking that
if they can throw around a degree other people will actually believe
it. "I'm an electrical engineer, but I'm trying to fix my stereo
and ...." The dot, dot, dot actually explains they don't know anything
and it was all ploy of the clueless.

That may not be your case, but how are we supposed to know? All
the time we see barely literate posts, people who expect us to know
what they want when they don't throw in the details. So someone asks
about how they can't use the XR2206 at 2MHz, and they get a long thread
about it all, and then finally it's revealed that the original poster
knows nothing and doesn't have the background to see beyond the XR2206
that they are familiar with because they've used it as an audio generator.

You post about a device that you don't know where to get, or find a
datasheet, but that is identical to the beginner who posts the
same sort of question.

You didn't even bother telling us that it was a Russian device, which
probably wouldn't have helped your quest but at least gives your post
context.

Without that context, it most definitely looks like a house number.
And since you didn't deal with the real issue, but instead blustered
about your experience, you made the whole thing worse. If you can't
be bothered explaining how you need these devices that you know
nothing about, then how is your post different from someone asking
about where to get a tunnel diode? We've had those too over the years
and all of them were from some beginner who found some old schematic
on the internet and couldn't know that the schematic is old and that
tunnel diodes had a very brief reign. There actually are legitimate
reasons for someone needing a tunnel diode, not very many at this point
but they do exist, but the poster who says they need it for the sweep
trigger in their oscilliscope, or as some exotic pulse generator, I
believe we have had people ask for those reasons, they would actually
provide the need for that tunnel diode, because they know that otherwise
the device is useless at this point.

Even now that we know it's a Russian device, one of your multi-posted
messages in another newsgroup said something about that, the answer
will still likely be a resounding nothing.

You're still the expert. How can someone have Russian devices but
not have insight into where they might find replacements or datasheets?
There are likely very few people reading this newsgroup that deals with
Russian devices. You at least have the advantage of knowing what
this device is used in (or we are led to assume that), that context
should help you at least find replacement devices.

Find a company in Russia that sells transistors. Find a Russian newsgroup
and ask there. Get a browser that deals with Cyrillic and start browsing.
The same technics for finding information about exotic devices should
apply here, with the caveat that the suitable webpages may be in Russian.
Have you even done a websearch on the part number, just in case it
actually gets a hit? If there are multiple hits, it most may be
unrelated, but sometimes you actually are lucky.

Of course, we still don't actually know that it's Russian, all we
know is that you claim it to be so. No context, no information about
what equipment has these devices so we can't actually decide ourselves.

Post about the equipment, post about the package the device is in, post
about the results you get when you test it with an ohmmeter, and then
a general picture will build up that at least starts to allow suggestions
of suitable substitutes.

The truth remains, either none of this is new to you, or it all is.
Which means either you expect too much, or you are clueless.

Michael

 

[Michael A. Terrell]

Arlowe wrote:

krw used his keyboard to write :
In article <2933ea53-af2a-43a8-86c7-d9e2ec400d99@
35g2000pry.googlegroups.com>, altzone@gmail.com says...
On Jan 21, 10:40 pm, krw <k...@att.zzzzzzzzz> wrote:
In article <9caaa5aa-54e2-4f21-a324-1f2ca8bdd389
@n33g2000pri.googlegroups.com>, altz...@gmail.com says...



On Jan 21, 2:09 pm, krw <k...@att.bizzzzzzzzzzz> wrote:
On Tue, 20 Jan 2009 19:06:15 -0800 (PST), "David L. Jones"
altz...@gmail.com> wrote:
On Jan 21, 12:22 pm, krw <k...@att.bizzzzzzzzzzz> wrote:
On Tue, 20 Jan 2009 22:05:27 -0300, YD <ydtech...@techie.com> wrote:
Late at night, by candle light, Arlowe <bare.ar...@gmail.com> penned
this immortal opus:

krw used his keyboard to write :
In article <mn.a5307d9188b78d0d.90...@gmail.com>,
bare.ar...@gmail.com says...
krw explained on 19/01/2009 :
On Sun, 18 Jan 2009 19:35:00 +1100, Arlowe <bare.ar...@gmail.com
wrote:

on 16/01/2009, Paul supposed :
On Jan 15, 2:19 pm, "David L. Jones" <altz...@gmail.com> wrote:
"Paul" <energymo...@gmail.com> wrote in message
news:54c2d7cf-c506-4647-b272-17d608c8854a@x8g2000yqk.googlegroups.com...
I'm testing a new DMM I purchased, AM-240 by Amprobe. It
claims *over* 100Mohm impedance in 400.0mV mode.
Nothing new there, many DMM's have selectable "high impedance"
or "HI-Z" modes on the mV range. e.g. the Fluke 87.
I've looked at the specs of ~ 30 DMM's today, include a lot of
fluke's, and never seen anything near 14Gohms impedance.
Keithley has an electrometer that's probably higher. Most DMM's
are around 10Mohms (not gigaohms) input impedance. Don't you
think 14 gigaohms is a bit high?

PL

The evil thing about Voltmeters with very high impedance is they
will read induced voltages that analog meters wouldn't.
It makes a voltmeter useless for checking for live circuits in a
crowded panel.

A craftsman never blames tools for his failures. Hackers, on the
other hand...

If you work with electricity you had better know the limitations of
your tools or you will find them...the hard way.
That is certainly true (though perhaps your heirs are the ones who
will find you), but doesn't modify my statement. In this case, the
tool *can* be used as long as the one using it knows what he's
doing.

Ok....everything seems to pass right over your head....
I pointed out a limitation of a DMM and you seem to be inferring that
I am somehow a hack who blames his tools...
BTW> I am not a "craftsman" I am an electrcian..
You don't do what I do for as many years as I have without knowing
what the fuck you are doing.

What's wrong with using a hi Z voltmeter in a live panel? I do it more
often than I really care for, and never have a problem.
There isn't anything wrong with it. Analog meters are dead. High
impedance digital meters are only a problem if there is a loose nut
inside the panel, holding the leads.
Then I suppose Fluke and others make all those purpose designed Low-Z
electrical meters for loose nuts then?
...and electricians who know nothing about electricity, perhaps.
But at least smart enough to chose the right tool for the job.

For an electrician who know nothing about electricity (99.44% of
them, apparently), or if that's all one is ever going to do with
the meter, perhaps.

Yes, electricians generally just do just the one similar job. That's
why they make meters designed for just such specific purposes.
Giving your average electrician say a Fluke 289 is a bit overkill and
would likely not be as productive as a more job specific instrument.

That wasn't at issue here. The statement was made that a high
impedance meter couldn't be used and that a low impedance *ANALOG*
meter was a necessity. It's certainly not true, though one has to
understand what one is doing, again a rarity in this group.

I didn't say you had to use an analog meter.
I said that they do not have the same problem. An analog meter "IS A
LOAD" a DMM is NOT.

Really? They both use resistive divider networks across the DUT.


--
http://improve-usenet.org/index.html

aioe.org, Goggle Groups, and Web TV users must request to be white
listed, or I will not see your messages.

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm


There are two kinds of people on this earth:
The crazy, and the insane.
The first sign of insanity is denying that you're crazy.