D
dd
Guest
A chip that gives good LC oscillator results should give crystal
performance that is better by the ratio of the Qs.
--
dd
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performance that is better by the ratio of the Qs.
--
dd
M
Michael A. Covington
Guest
That is exactly how large capacitors are made.
Medium-capacitance capacitors (e.g., 0.1 uF) have many thin layers of
metallized plastic film, very close together.
Large ones (e.g., 1000 uF) use an electrolytic process to make conductive
layers that are insulated from each other and yet very, very close together.
A coil and capacitor don't work as an AC battery because of resistance. (No
capacitor or inductor has zero resistance.) But a large capacitor can work
as a DC battery; for example, that's how HP calculators retain their
programming while you are changing the batteries.
"Paul" <paulw@mmail.ath.cx> wrote in message
news:3ba4d769.0409121445.3fdfca60@posting.google.com...
Medium-capacitance capacitors (e.g., 0.1 uF) have many thin layers of
metallized plastic film, very close together.
Large ones (e.g., 1000 uF) use an electrolytic process to make conductive
layers that are insulated from each other and yet very, very close together.
A coil and capacitor don't work as an AC battery because of resistance. (No
capacitor or inductor has zero resistance.) But a large capacitor can work
as a DC battery; for example, that's how HP calculators retain their
programming while you are changing the batteries.
"Paul" <paulw@mmail.ath.cx> wrote in message
news:3ba4d769.0409121445.3fdfca60@posting.google.com...
Hi
From our physics textbook, the capacitance is inversely proportional
to spacing between the 2 plates. what's to prevent us from making the
spacing very small and hence very high capacitance? Coupled with an
inductor, one can make a AC battery out of it. Will too small a
spacing cause a leakage and hence unpredictatible discharge? Thanks
T
Tim Wescott
Guest
Paul wrote:
you make the material thinner the voltage that the capacitor can
withstand goes down. You can see this in electrolytic capacitors, where
for a given size of case the capacitance diminishes as the voltage
rating goes down. In fact, I've noticed that for a given size of case
the capacitance is roughly inversely proportional to the square of the
voltage rating, indicating that you can store so much energy in the
given volume, and no more.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Dielectric strength of any given material is is in volts/meter, so asHi
From our physics textbook, the capacitance is inversely proportional
to spacing between the 2 plates. what's to prevent us from making the
spacing very small and hence very high capacitance? Coupled with an
inductor, one can make a AC battery out of it. Will too small a
spacing cause a leakage and hence unpredictatible discharge? Thanks
you make the material thinner the voltage that the capacitor can
withstand goes down. You can see this in electrolytic capacitors, where
for a given size of case the capacitance diminishes as the voltage
rating goes down. In fact, I've noticed that for a given size of case
the capacitance is roughly inversely proportional to the square of the
voltage rating, indicating that you can store so much energy in the
given volume, and no more.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
Guest
paulw@mmail.ath.cx (Paul) wrote:
No, it'll cause arcing, and immediate discharge.Will too small a
spacing cause a leakage
C
Chaos Master
Guest
Data received from Lewin A.R.W. Edwards on port COM1:
[]s
--
Chaos MasterŽ, posting from Brazil. REPLY TO GROUP!
"People told me I can't dress like a fairy.
I say, I'm in a rock band and I can do what the hell I want!"
-- Amy Lee
Note: this e-mail address goes to /dev/null.
BZX1019 looks like a ZENER diode.I'm repairing a fuel pump from a friend's 1971-vintage car, and I
encountered this component that I can't identify. It's a black plastic
cylindrical body with the part# (AMPOHM BZX 1019) silkscreened on it,
and two stranded wires (red and black) coming out of one end.
ampohm.co.uk has no information. It looks rather like some kind of
custom hybrid part.
[]s
--
Chaos MasterŽ, posting from Brazil. REPLY TO GROUP!
"People told me I can't dress like a fairy.
I say, I'm in a rock band and I can do what the hell I want!"
-- Amy Lee
Note: this e-mail address goes to /dev/null.
L
Lewin A.R.W. Edwards
Guest
Chaos Master wrote:
Any idea what voltage?Data received from Lewin A.R.W. Edwards on port COM1:
cylindrical body with the part# (AMPOHM BZX 1019) silkscreened on it,
and two stranded wires (red and black) coming out of one end.
BZX1019 looks like a ZENER diode.
C
Chaos Master
Guest
Data received from Lewin A.R.W. Edwards on port COM1:
[]s
--
Chaos MasterŽ, posting from Brazil. REPLY TO GROUP!
"People told me I can't dress like a fairy.
I say, I'm in a rock band and I can do what the hell I want!"
-- Amy Lee
Note: this e-mail address goes to /dev/null.
10V or 19V, I think.Chaos Master wrote:
Data received from Lewin A.R.W. Edwards on port COM1:
cylindrical body with the part# (AMPOHM BZX 1019) silkscreened on it,
and two stranded wires (red and black) coming out of one end.
BZX1019 looks like a ZENER diode.
Any idea what voltage?
[]s
--
Chaos MasterŽ, posting from Brazil. REPLY TO GROUP!
"People told me I can't dress like a fairy.
I say, I'm in a rock band and I can do what the hell I want!"
-- Amy Lee
Note: this e-mail address goes to /dev/null.
T
Tom S
Guest
How about your head??
"G.K. Konnig" <bullmordt@yahoo.co.nz> wrote in message
news:3ff97a0d.0409111912.4dc06ae@posting.google.com...
"G.K. Konnig" <bullmordt@yahoo.co.nz> wrote in message
news:3ff97a0d.0409111912.4dc06ae@posting.google.com...
I need it for my weekly anal-inspection, because my boyfriend left me
a couple of days ago.
What do I need for a good anal-probe?
N
nospam
Guest
larwe@larwe.com (Lewin A.R.W. Edwards) wrote:
maximum current). .
voltage if you try to stop it. The diode allows the current to continue to
flow through the diode and coil in a circle. There is no 'kickback' because
you are not trying to stop the current.
The initial diode current will be the same as the coil current when the
contacts opened. The circulating current does work against the coil
resistance and diode voltage drop. The current decays as the energy stored
in the coil is turned into heat. The magnetic field reduces with the
current.
If you put a zener diode in series with the diode then the 'kickback' is
limited to the zener voltage and the circulating current has to work
against the zener voltage and will decay much more quickly.
The frequency the pump 'buzzes' at would be higher with a zener diode. That
would probably increase the pumping capacity maybe that is how it is
supposed to be?
If the BZX 1019 is a diode and zener in series then you would not measure
anything with a meter. You would need to apply more than the zener voltage
to get any current to flow. I would try to test if on a bench power supply,
with a low current limit wind up the voltage to see if and when current
starts to flow.
For the current it is (assuming the coil is powered long enough to reachHi,
AMPOHM seem to make a range of encapsulated parts for automotive
applications, mostly capacitors.
Right, I browsed their www site, but they don't provide much specific
info.
In this application I suspect a simple diode would do the job. A diode
That was my _guess_ but I wanted opinions. I couldn't see why a zener
would be necessary here, since it's known that the kickback voltage
will be the opposite polarity from the battery pulse.
The peak current in the diode will be the same as the current in the coil
which you can measure or work out from measuring the coil resistance.
It's hard to measure I in-ckt, but the coil has a resistance of about
6 ohm, so I can take it from there if it's a simple Ohm's law
calculation.
maximum current). .
The current in the coil wants to continue to flow, it will generate a highBut I thought the kickback voltage could be considerably
more than the supply voltage - like, hundreds of volts. What regulates
the speed with which the magnetic field collapses?
voltage if you try to stop it. The diode allows the current to continue to
flow through the diode and coil in a circle. There is no 'kickback' because
you are not trying to stop the current.
The initial diode current will be the same as the coil current when the
contacts opened. The circulating current does work against the coil
resistance and diode voltage drop. The current decays as the energy stored
in the coil is turned into heat. The magnetic field reduces with the
current.
If you put a zener diode in series with the diode then the 'kickback' is
limited to the zener voltage and the circulating current has to work
against the zener voltage and will decay much more quickly.
The frequency the pump 'buzzes' at would be higher with a zener diode. That
would probably increase the pumping capacity maybe that is how it is
supposed to be?
If the BZX 1019 is a diode and zener in series then you would not measure
anything with a meter. You would need to apply more than the zener voltage
to get any current to flow. I would try to test if on a bench power supply,
with a low current limit wind up the voltage to see if and when current
starts to flow.
D
Dieter Wiedmann
Guest
Ajay schrieb:
Regards,
Dieter
Use a complementary emitter follower to drive the MOSFET.Hi,
I am using an LM3485 to design a power conditioning cicuit that can
drive 10A at 12V (i/p 12 to 30V) . I am facing this interesting issue
-
As I need to have higher current the device size (of the PFET)
increases which in turn increases the input capacitance. However the
LM3485 can drive PFETs with less that 1000pF input capacitance. It is
very difficult to get a PFET with lower i/p capacitance
This does not turn on the transistor properly. Has anybody dealt with
this situation and is there a solution to this.
Regards,
Dieter
D
dd
Guest
In message <bec993c8.0409140126.1e18be52@posting.google.com>, Tim Shoppa
<shoppa@trailing-edge.com> writes
the 60s
The particular crystal design shows very little change of frequency
until the crystal dissipation exceeds 2.5uW, note that because of the
2.5M Q the displacement causes the quartz to approach the stress strain
non-linearity region above this dissipation and slight frequency changes
occur.
I design crystal maintaining circuits by determining the negative
resistance to commence oscillation, say -250 ohms for the 2.5MHZ , then
designing the bias / supply reduction to be able to reduce the negative
resistance to -50 ohms thus encompassing the range necessary to meet
start up and manufacturing tolerance.
You will find that this limited range of activity enables a linear swing
of 3V pp or so with a resistance in the collector.
If an inductor (parallel LC) is employed the swing can be greater but
stability may be compromised does not limit the linear swing. Again
note that as the servo reduces the collector current the start up swing
may be limited but as the activity reduces to a loop gain of 1 the
amplitude can me maintained in the linear swing region.
Note email no longer interrogated due to spam.
can equal a significant
--
dd
<shoppa@trailing-edge.com> writes
competition to Sulzer!. the state of the art for crystal standards indd <dd@ddwyer.demon.co.uk> wrote in message
news:<6lUnG9AMqdRBFwjo@ddwyer.demon.co.uk>...
A technique I first employed in 1968:
The activity of a colpitts type bipolar amplifier is dependent on the
gain of the device this can be reduced by changing the biassing to
decrease the collector current.The gm of colpitts / pierce oscillator
with collector to base feedback resistor to autobias can be reduced by
reducing the entire supply voltage by servo control .
One thing that I'm learning (or I knew but never realized) is that many
ways of implementing AGC will inherently reduce large and even medium-signal
handling ability as bias points shift around and (in recommendations like
yours) you explicitly reduce the headroom available for output swing.
This isn't a problem if you keep the amplitudes low...
For example, the AGC loop in the Sulzer oscillator keeps the amplitude
of the 2.5MHz oscillator at 0.02V P-P. I always thought this was really
miniscule, but I'm beginning to realize that with classic AGC implementations
this may be a sweet spot.
The "new way", using gold-plated variable-gain amps like the AD603
don't seem quite so limited. (I'm sure there's a sweet spot for minimum
THD and it's not having the output go from rail to the other, though!)
Tim.
The circuit I described was also for a 2.5MHz 5th overtone crystal in
the 60s
The particular crystal design shows very little change of frequency
until the crystal dissipation exceeds 2.5uW, note that because of the
2.5M Q the displacement causes the quartz to approach the stress strain
non-linearity region above this dissipation and slight frequency changes
occur.
I design crystal maintaining circuits by determining the negative
resistance to commence oscillation, say -250 ohms for the 2.5MHZ , then
designing the bias / supply reduction to be able to reduce the negative
resistance to -50 ohms thus encompassing the range necessary to meet
start up and manufacturing tolerance.
You will find that this limited range of activity enables a linear swing
of 3V pp or so with a resistance in the collector.
If an inductor (parallel LC) is employed the swing can be greater but
stability may be compromised does not limit the linear swing. Again
note that as the servo reduces the collector current the start up swing
may be limited but as the activity reduces to a loop gain of 1 the
amplitude can me maintained in the linear swing region.
Note email no longer interrogated due to spam.
can equal a significant
--
dd
W
Watson A.Name - \"Watt Su
Guest
"Lewin A.R.W. Edwards" <larwe@larwe.com> wrote in message
news:dC61d.25711$Wv5.1114@newsread3.news.atl.earthlink.net...
[snip]
assume it's a capacitor? And that's usually what's put across these
kinds of things, for RFI and spark suppression. I would try to get
another one from a junk yard or some other source, and measure both to
see if the original is okay. If not, then replace it.
news:dC61d.25711$Wv5.1114@newsread3.news.atl.earthlink.net...
[snip]
Since Ampohm seems to be a capacitor maker, wouldn't it seem prudent toAny insights appreciated.
assume it's a capacitor? And that's usually what's put across these
kinds of things, for RFI and spark suppression. I would try to get
another one from a junk yard or some other source, and measure both to
see if the original is okay. If not, then replace it.
W
Watson A.Name - \"Watt Su
Guest
"Tim Wescott" <tim@wescottnospamdesign.com> wrote in message
news:10k9o9dslepvn48@corp.supernews.com...
the following.
news:10k9o9dslepvn48@corp.supernews.com...
I think you got that backwards. At least that's the way it sounds, fromPaul wrote:
Hi
From our physics textbook, the capacitance is inversely proportional
to spacing between the 2 plates. what's to prevent us from making
the
spacing very small and hence very high capacitance? Coupled with an
inductor, one can make a AC battery out of it. Will too small a
spacing cause a leakage and hence unpredictatible discharge? Thanks
Dielectric strength of any given material is is in volts/meter, so as
you make the material thinner the voltage that the capacitor can
withstand goes down. You can see this in electrolytic capacitors,
where
for a given size of case the capacitance diminishes as the voltage
rating goes down.
the following.
In fact, I've noticed that for a given size of case
the capacitance is roughly inversely proportional to the square of the
voltage rating, indicating that you can store so much energy in the
given volume, and no more.
--
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
J
Jamie
Guest
look for serial rom chips with a 4 or more bit output.
you will need a programmer etc..
of permanet data is not what you need then look for a
serial ram chip.
chenzen wrote:
you will need a programmer etc..
of permanet data is not what you need then look for a
serial ram chip.
chenzen wrote:
Hi to all,
I would like to record tones or simple voice messages on IC's and get
the output through a speaker.
I would be grateful if somebody could help me with the type of IC needed
and the way to go about it.
D
Dbowey
Guest
<< Anyone sell off the shelf inductors in the range of 1 Henry? Everyone
I call can make it custom but doesn't have off the shelf items.
Here's one.
CA03 Pi Filter Choke 1 Henry 500 mA Ł46.33
<A
HREF="http://www.sowter.co.uk/numindexbody.htm">http://www.sowter.co.uk/nu
mindexbody.htm</A>
Don
I call can make it custom but doesn't have off the shelf items.
Here's one.
CA03 Pi Filter Choke 1 Henry 500 mA Ł46.33
<A
HREF="http://www.sowter.co.uk/numindexbody.htm">http://www.sowter.co.uk/nu
mindexbody.htm</A>
Don
D
Dbowey
Guest
Better yet (smaller, less costly):
CB01 Pi Filter Choke 1 Henry 200 mA Ł33.44
Don
CB01 Pi Filter Choke 1 Henry 200 mA Ł33.44
Don
F
Franc Zabkar
Guest
On 15 Sep 2004 03:27:30 -0700, hellokula@yahoo.com (chenzen) put
finger to keyboard and composed:
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
finger to keyboard and composed:
Check Winbond's range of speech processor ICs.I would like to record tones or simple voice messages on IC's and get
the output through a speaker.
I would be grateful if somebody could help me with the type of IC needed
and the way to go about it.
- Franc Zabkar
--
Please remove one 's' from my address when replying by email.
M
Michael A. Covington
Guest
You may be able to use one side of a commonly available transformer. How
much current does it need to carry?
"Asa Cannell" <acannell@wwc.com> wrote in message
news:51ca721c.0409151242.4001e583@posting.google.com...
much current does it need to carry?
"Asa Cannell" <acannell@wwc.com> wrote in message
news:51ca721c.0409151242.4001e583@posting.google.com...
Anyone sell off the shelf inductors in the range of 1 Henry? Everyone
I call can make it custom but doesn't have off the shelf items.
Asa
C
Clarence
Guest
"Asa Cannell" <acannell@wwc.com> wrote in message
news:51ca721c.0409151242.4001e583@posting.google.com...
Analog filter or power?
How much current?
Do you hace a limit on Resistance?
AC ripple?
news:51ca721c.0409151242.4001e583@posting.google.com...
Anyone sell off the shelf inductors in the range of 1 Henry? Everyone
I call can make it custom but doesn't have off the shelf items.
Asa
Analog filter or power?
How much current?
Do you hace a limit on Resistance?
AC ripple?
G
Gareth Magennis
Guest
Look for ISD2560P and ISD1416P
Gareth.
"chenzen" <hellokula@yahoo.com> wrote in message
news:19765984.0409150227.7b4d66d0@posting.google.com...
Gareth.
"chenzen" <hellokula@yahoo.com> wrote in message
news:19765984.0409150227.7b4d66d0@posting.google.com...
Hi to all,
I would like to record tones or simple voice messages on IC's and get
the output through a speaker.
I would be grateful if somebody could help me with the type of IC needed
and the way to go about it.