B
BeeJ
Guest
Ian Field brought next idea :
I could live with that. Where can I buy a complete unit?
D
default
Guest
On Wed, 24 Apr 2013 02:18:02 +0000, passerby
<f6ceedb9c75b52f7fcc0a55cf0cfbf5d_911@example.com> wrote:
automobile wheel hubs (a stupid idea IMO, but what the customer
wanted). The idea was to give the spokes some forward/reverse
appearance whilst driving down the street (this is the Fast and
Furious mind set)...
The white leds show quite a bit of "tailing" when observed on a scope
via a photo diode, and didn't have the sharp definition of a xenon
strobe (blurry spokes).
Xenon was out of the question for size and ruggedness, but a RGB led
in a "Piranha" style package worked well (and added a whole new level
of complexity since the customer now wanted fading colors or the
ability to match the color scheme of the F&F decor).
I thought blue-white had the greatest impact.
<f6ceedb9c75b52f7fcc0a55cf0cfbf5d_911@example.com> wrote:
I built a strobe like that. We were making these strobes to go on
automobile wheel hubs (a stupid idea IMO, but what the customer
wanted). The idea was to give the spokes some forward/reverse
appearance whilst driving down the street (this is the Fast and
Furious mind set)...
The white leds show quite a bit of "tailing" when observed on a scope
via a photo diode, and didn't have the sharp definition of a xenon
strobe (blurry spokes).
Xenon was out of the question for size and ruggedness, but a RGB led
in a "Piranha" style package worked well (and added a whole new level
of complexity since the customer now wanted fading colors or the
ability to match the color scheme of the F&F decor).
I thought blue-white had the greatest impact.
I
Ian Field
Guest
"BeeJ" <spamnot@nospam.com> wrote in message
news:kl9uro$s6i$1@speranza.aioe.org...
the red & green are fairly close but the blue is almost double. You can't
just strap the 3 in parallel.
The first place I'd look is probably Farnell, but outlets may be different
where you are.
news:kl9uro$s6i$1@speranza.aioe.org...
There is yet another tiny problem - the 3 LEDs require different Vf each,
the red & green are fairly close but the blue is almost double. You can't
just strap the 3 in parallel.
The first place I'd look is probably Farnell, but outlets may be different
where you are.
U
Uncle Steve
Guest
On Mon, May 06, 2013 at 02:35:52PM -0500, Tim Wescott wrote:
something and then delete the references header, which I forgot to do
in this case. What happens next is dependant on the newsreader you
use.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
Sorry. My newsreader crashes when I 'post' so I have to reply to
something and then delete the references header, which I forgot to do
in this case. What happens next is dependant on the newsreader you
use.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
U
Uncle Steve
Guest
On Mon, May 06, 2013 at 12:01:44PM -0400, Uncle Steve wrote:
mistake that I did not remove the references header.
At any rate, I set up a separate pair of 2n2222, 10K resistor, and
BC557 similar to the input stage above as well as a LED. Then I
connected a small spool of insulated wire to the base of the 2n2222
and then let it out a couple of feet until the LED stayed onish without
my hands being near the device.
The result is a strong 6-7MHz signal for a bunch of cycles and then
some dead time. It looks like there could be some FM in there, and on
the high part of the cycle there appears to be an additional small
signal, but I can't resolve any detail with my equipment.
If I hold the spool in my hand the amount of on time changes
considerably depending how much of my hand is in contact with the
plastic and insulation. With palm open, there is one rise/fall cycle
at about 6.5MHz when my hand is about 6in from the wire. As my hand
gets closer, a second peak appears and so on until there is a train of
several dozen cycles at or near the measured frequency.
Any idea what the hell that signal might be?
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
As suggested, I moved this out of the existing thread. It was an
mistake that I did not remove the references header.
At any rate, I set up a separate pair of 2n2222, 10K resistor, and
BC557 similar to the input stage above as well as a LED. Then I
connected a small spool of insulated wire to the base of the 2n2222
and then let it out a couple of feet until the LED stayed onish without
my hands being near the device.
The result is a strong 6-7MHz signal for a bunch of cycles and then
some dead time. It looks like there could be some FM in there, and on
the high part of the cycle there appears to be an additional small
signal, but I can't resolve any detail with my equipment.
If I hold the spool in my hand the amount of on time changes
considerably depending how much of my hand is in contact with the
plastic and insulation. With palm open, there is one rise/fall cycle
at about 6.5MHz when my hand is about 6in from the wire. As my hand
gets closer, a second peak appears and so on until there is a train of
several dozen cycles at or near the measured frequency.
Any idea what the hell that signal might be?
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
A
amdx
Guest
On 5/6/2013 3:01 PM, Uncle Steve wrote:
Fix your newsreader!
T
Tim Wescott
Guest
On Mon, 06 May 2013 16:15:36 -0400, Uncle Steve wrote:
its emitter to +18V and its collector to the base of Q1. (Q1 should have
its collector _connected_!!). Q3 is configured to deliver current to the
base of Q2, but it needs to pull current -- ?!?!?!?!
Could you be showing the emitters and collectors of Q2 and Q3 reversed?
If it's doing anything at all (which presumably it is) then amongst your
various transistors you have tons of uncontrolled gain, so it's not
surprising that its oscillating or doing other weird stuff.
What's your goal? A charge current that's proportional to the voltage at
the SW1 end of R3?
I'd have to think about how to take that collection of transistors and
make a stable circuit out of it, but if you're really building to that
schematic then I suspect that you need to make some changes!
Note that if you're charging a lead-acid battery (gel or flood) the ideal
charge profile is to limit both voltage and current. Voltage is limited
to some magic number (which I can never remember -- look it up), and
current is limited either by the charger's capabilities or the
battery's. When the charge of the battery is low it accepts charge at
the constant current, but then as it charges you must drop the current to
hold the voltage constant.
--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?
Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
I'm not making sense of your schematic. If Q2 is a PNP it should have
its emitter to +18V and its collector to the base of Q1. (Q1 should have
its collector _connected_!!). Q3 is configured to deliver current to the
base of Q2, but it needs to pull current -- ?!?!?!?!
Could you be showing the emitters and collectors of Q2 and Q3 reversed?
If it's doing anything at all (which presumably it is) then amongst your
various transistors you have tons of uncontrolled gain, so it's not
surprising that its oscillating or doing other weird stuff.
What's your goal? A charge current that's proportional to the voltage at
the SW1 end of R3?
I'd have to think about how to take that collection of transistors and
make a stable circuit out of it, but if you're really building to that
schematic then I suspect that you need to make some changes!
Note that if you're charging a lead-acid battery (gel or flood) the ideal
charge profile is to limit both voltage and current. Voltage is limited
to some magic number (which I can never remember -- look it up), and
current is limited either by the charger's capabilities or the
battery's. When the charge of the battery is low it accepts charge at
the constant current, but then as it charges you must drop the current to
hold the voltage constant.
--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?
Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
U
Uncle Steve
Guest
On Mon, May 06, 2013 at 03:38:19PM -0500, amdx wrote:
similar to Larry Wall's story and I fear it will be a while yet before
I have running code.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
I started doing that, but the path I went down is superficially
similar to Larry Wall's story and I fear it will be a while yet before
I have running code.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
U
Uncle Steve
Guest
On Mon, May 06, 2013 at 03:40:00PM -0500, Tim Wescott wrote:
is described at the following URL:
http://www.talkingelectronics.com/projects/TheTransistorAmplifier/TheTransistorAmplifier-P1.html#THEDARLINGTON
and will operate at 488Hz PWM as described above.
sort of capacitance issue with Q2/Q3. I fiddled with a few small
ceramic capacitors in a naive fashion, but I did not accomplish
anything other than destroying a 2n2222. I simply haven't
internalized enough information about how these things operate to
figure out what I should do to eliminate the distortion.
charge voltage should be 13.8V and the float voltage 13.5V.
The current strategy I'm working on will limit the average current
over time with PWM, measuring instantaneous current when Q1 is on to
drive a feedback loop to set PWM duty-cycle. I'll be reading supply
voltage, and voltage at either side of the .5 Ohm sense resister at
various times throughout the PWM cycle. The software will do ADC at
about 125KHz so there's lots of room to average things nicely. I
assume there's no real problem with allowing current to spike at short
intervals if the battery naturally wants more amps than my PS will
supply on a continual basis. I may be wrong, and it may be a simple
matter to install a load resistor with the sense resistor. I'm still
in larval stage so this stuff is still a little mysterious.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
I don't think so. The arrangement is described as a Sziklai Pair, and
is described at the following URL:
http://www.talkingelectronics.com/projects/TheTransistorAmplifier/TheTransistorAmplifier-P1.html#THEDARLINGTON
SW1 is a stand in for the TTL level output from a microcontroller pin
and will operate at 488Hz PWM as described above.
The oscillation showing up at the base of Q1 may be the result of some
sort of capacitance issue with Q2/Q3. I fiddled with a few small
ceramic capacitors in a naive fashion, but I did not accomplish
anything other than destroying a 2n2222. I simply haven't
internalized enough information about how these things operate to
figure out what I should do to eliminate the distortion.
I understand that. The preliminary figures I have suggest that the
charge voltage should be 13.8V and the float voltage 13.5V.
The current strategy I'm working on will limit the average current
over time with PWM, measuring instantaneous current when Q1 is on to
drive a feedback loop to set PWM duty-cycle. I'll be reading supply
voltage, and voltage at either side of the .5 Ohm sense resister at
various times throughout the PWM cycle. The software will do ADC at
about 125KHz so there's lots of room to average things nicely. I
assume there's no real problem with allowing current to spike at short
intervals if the battery naturally wants more amps than my PS will
supply on a continual basis. I may be wrong, and it may be a simple
matter to install a load resistor with the sense resistor. I'm still
in larval stage so this stuff is still a little mysterious.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
T
Tim Wescott
Guest
On Mon, 06 May 2013 18:04:51 -0400, Uncle Steve wrote:
Sziklai pair is only going to work well when it's all the way off or all
the way on -- PWM is good, but don't expect it to work in anything
resembling a linear fashion.
+18V Q1 ___ battery
o---------------- ------|___|-----o
\ ^
---
|
|
.-.
| |
| |
'-'
|
|
|<
.---| Q2
| |\
| |
| |
| |
PWM |/ |
o---------| Q3 |
|> |
| |
| |
=== ===
GND GND
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)
--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?
Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
Look again -- I don't think you're there. One huge thing to note: your
Sziklai pair is only going to work well when it's all the way off or all
the way on -- PWM is good, but don't expect it to work in anything
resembling a linear fashion.
+18V Q1 ___ battery
o---------------- ------|___|-----o
\ ^
---
|
|
.-.
| |
| |
'-'
|
|
|<
.---| Q2
| |\
| |
| |
| |
PWM |/ |
o---------| Q3 |
|> |
| |
| |
=== ===
GND GND
(created by AACircuit v1.28.6 beta 04/19/05 www.tech-chat.de)
--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?
Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
U
Uncle Steve
Guest
On Mon, May 06, 2013 at 06:32:52PM -0500, Tim Wescott wrote:
suggests I was counting on current-limiting to occur in the wrong
place.
The software feedback loop ought to allow the ideal pulse width to
'fly' automatically at the correct setting, assuming the ADC readings
are reasonably accurate. Theoretically, I should also be able to
detect collapse (?) of the transformer flux if the current draw grows
too large, which would be a nice bonus.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
I will consider that, but note that Q1 is NPN. What you propose
suggests I was counting on current-limiting to occur in the wrong
place.
The software feedback loop ought to allow the ideal pulse width to
'fly' automatically at the correct setting, assuming the ADC readings
are reasonably accurate. Theoretically, I should also be able to
detect collapse (?) of the transformer flux if the current draw grows
too large, which would be a nice bonus.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
J
Jasen Betts
Guest
On 2013-05-07, Uncle Steve <stevet810@gmail.com> wrote:
+18V ----+---+ _+----->|--[Rsense]-----> BAT+
| \ /|
| ----- '3055
| |
+ +
_\| /
------ BC557
|
[100] 0.25W
|
+
/
pwm in |/
---[1K]--| PN2222
|\
_\|
+
|
0V ---+---
in the secondary circuit and the by detecting it you're measuring the
line voltage more than any other variable.
--
ââ 100% natural
--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
You can do it like this using the transistors you have.
+18V ----+---+ _+----->|--[Rsense]-----> BAT+
| \ /|
| ----- '3055
| |
+ +
_\| /
------ BC557
|
[100] 0.25W
|
+
/
pwm in |/
---[1K]--| PN2222
|\
_\|
+
|
0V ---+---
saturation will show in the primary current much more than anything on
in the secondary circuit and the by detecting it you're measuring the
line voltage more than any other variable.
--
ââ 100% natural
--- news://freenews.netfront.net/ - complaints: news@netfront.net ---
U
Uncle Steve
Guest
On Tue, May 07, 2013 at 06:43:00AM +0000, Jasen Betts wrote:
close to the threshold where it allows something like full power to
flow through the 3055. With 100k or less I was seeing my (cheap)
meter show fluxuating nonsense voltages at the emitter of up to 1500V,
although my scope showed nothing much amiss at lower frequency
settings. I was thinking that the 3055 was somehow generating large
spikes with the rising edge of the pulse, but I did not test it
exhaustively.
am not familiar enough with the nomenclature to avoid stepping on my
dick. I probably should say that the PWM will limit the average
/power/ going in the battery, which is what really matters.
As I understand it, volts are sort of like the size of the pipe;
amperes are like the pressure or the rate of flow, and power is the
throughput. Of course it isn't plumbing and there isn't any water.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
How do you arrive at 100 ohms? I was using 200K because the value is
close to the threshold where it allows something like full power to
flow through the 3055. With 100k or less I was seeing my (cheap)
meter show fluxuating nonsense voltages at the emitter of up to 1500V,
although my scope showed nothing much amiss at lower frequency
settings. I was thinking that the 3055 was somehow generating large
spikes with the rising edge of the pulse, but I did not test it
exhaustively.
That's what I meant. I don't like to be wrong, so it bugs me that I
am not familiar enough with the nomenclature to avoid stepping on my
dick. I probably should say that the PWM will limit the average
/power/ going in the battery, which is what really matters.
As I understand it, volts are sort of like the size of the pipe;
amperes are like the pressure or the rate of flow, and power is the
throughput. Of course it isn't plumbing and there isn't any water.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
U
Uncle Steve
Guest
On Tue, May 07, 2013 at 08:52:59AM -0400, Uncle Steve wrote:
the primary effect of using anything lower than 10K is damage to
either the 2n2222 or the BC557. The failure mode appears to be mainly
permanently shorting collector and emitter, but I observed partially
damaged transistors which would produce 1V at the base of Q1 in the
idle state. Since I've been doing a fair bit of fooling around in the
last 24 hours, it seems I've collected a half-dozen damaged
transistors, which probably contributed to some of the anomalous
readings I have had.
Using fresh parts and 100K between Q3 and Q2, everything is good. The
battery is only drawing 1.6A at this time so I can't easily test the
circuit at higher currents without draining the battery a whole lot.
The ripple at the base of Q1 is still there at 60mVpp which propagates
to the emitter, although I wouldn't see it without the diode. My
guess is that the Sziklai pair is too sensitive for this application,
but I don't really know why or what to do about it. The proximal
sensitivity to mass is another concern, and I don't know whether there
is an internal oscillation occuring that is amplified by a proximal
mass, or whether a proximal mass is triggering the amplification of
power-line hum. An extra .22uF filter capacitor on the 5V rail has no
effect.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
I quickly experimented with some lower value resisters and found that
the primary effect of using anything lower than 10K is damage to
either the 2n2222 or the BC557. The failure mode appears to be mainly
permanently shorting collector and emitter, but I observed partially
damaged transistors which would produce 1V at the base of Q1 in the
idle state. Since I've been doing a fair bit of fooling around in the
last 24 hours, it seems I've collected a half-dozen damaged
transistors, which probably contributed to some of the anomalous
readings I have had.
Using fresh parts and 100K between Q3 and Q2, everything is good. The
battery is only drawing 1.6A at this time so I can't easily test the
circuit at higher currents without draining the battery a whole lot.
The ripple at the base of Q1 is still there at 60mVpp which propagates
to the emitter, although I wouldn't see it without the diode. My
guess is that the Sziklai pair is too sensitive for this application,
but I don't really know why or what to do about it. The proximal
sensitivity to mass is another concern, and I don't know whether there
is an internal oscillation occuring that is amplified by a proximal
mass, or whether a proximal mass is triggering the amplification of
power-line hum. An extra .22uF filter capacitor on the 5V rail has no
effect.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
T
Tom Biasi
Guest
On 5/7/2013 8:52 AM, Uncle Steve wrote:
Power is the rate of doing work.
J
Jim Thompson
Guest
On Tue, 07 May 2013 13:15:10 -0400, Tom Biasi <tombiasi@optonline.net>
wrote:
equivalent to resistance.
Volts equates to pressure
Current equates to flow rate
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
wrote:
The length of the pipe divided by the diameter is proportionally
equivalent to resistance.
Volts equates to pressure
Current equates to flow rate
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
T
Tom Biasi
Guest
On 5/7/2013 1:18 PM, Jim Thompson wrote:
On Tue, 07 May 2013 13:15:10 -0400, Tom Biasi <tombiasi@optonline.net
wrote:
On 5/7/2013 8:52 AM, Uncle Steve wrote:
As I understand it, volts are sort of like the size of the pipe;
amperes are like the pressure or the rate of flow, and power is the
throughput. Of course it isn't plumbing and there isn't any water.
Regards,
Uncle Steve
Even with water, pressure and rate of flow are not the same thing.
Power is the rate of doing work.
The length of the pipe divided by the diameter is proportionally
equivalent to resistance.
Volts equates to pressure
Current equates to flow rate
...Jim Thompson
I thought he might look it up himself Jim
U
Uncle Steve
Guest
On Tue, May 07, 2013 at 09:43:54AM -0700, George Herold wrote:
less at random for the purpose of experimentation. I'm not really
concerned with the fact that the BC557 is 'smaller' than the 2n2222,
only that there is enough juice getting to the base of the MJE3055,
which appears to be true at this point. Before I hooked up the
battery, I used a 36VDC permanent magnet motor and stalled it by hand
to show almost 4A going through the sense resistor.
I suppose you're correct, as the diagrams of Darlington pairs don't
include anything like the 100K I have installed on the Emitter of the
2n2222, and clearly the last BC557 I blew up was due to the greater
driving power of the 2n2222. I see 26mA going out of the PNP.
Perhaps I don't really need the BC557, and could get away with just
the 2n2222 and an appropriate current limiting resistor.
What led to using the PNP transistor was my initial misunderstanding
of how the 3055 worked, and I assumed the base-emitter voltage of 5V
meant that it should have 5V going in to it max, but I failed to
appreciate that I have the 3055 and battery configured in the emitter-
follower configuration. Perhaps I should move the 3055 to the other
side of the battery and try again.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
Those are just the parts I have on hand, which were selected more or
less at random for the purpose of experimentation. I'm not really
concerned with the fact that the BC557 is 'smaller' than the 2n2222,
only that there is enough juice getting to the base of the MJE3055,
which appears to be true at this point. Before I hooked up the
battery, I used a 36VDC permanent magnet motor and stalled it by hand
to show almost 4A going through the sense resistor.
I suppose you're correct, as the diagrams of Darlington pairs don't
include anything like the 100K I have installed on the Emitter of the
2n2222, and clearly the last BC557 I blew up was due to the greater
driving power of the 2n2222. I see 26mA going out of the PNP.
Perhaps I don't really need the BC557, and could get away with just
the 2n2222 and an appropriate current limiting resistor.
What led to using the PNP transistor was my initial misunderstanding
of how the 3055 worked, and I assumed the base-emitter voltage of 5V
meant that it should have 5V going in to it max, but I failed to
appreciate that I have the 3055 and battery configured in the emitter-
follower configuration. Perhaps I should move the 3055 to the other
side of the battery and try again.
Regards,
Uncle Steve
--
There should be a special word in the English language to identify
people who create problems and then turn around and offer up their own
tailor-made bogus non-solutions designed to completely avoid the root
causes of the situation under consideration. 'Traitor' might be a
good choice, but lacks the requisite specificity. One of the problems
with contemporary English is it lacks many such words that would
otherwise categorically identify certain kinds of person, place, or
thing -- making it difficult or impossible to think analytically about
such objects. These shortcomings of the English lexicon are
representative of Orwellian linguistics at work in the real world.
J
Jim Thompson
Guest
On Tue, 07 May 2013 13:27:24 -0400, Tom Biasi <tombiasi@optonline.net>
wrote:
;-)
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
wrote:
Ooooops! Sorry! He is flailing quite a bit. I remember being thereOn 5/7/2013 1:18 PM, Jim Thompson wrote:
On Tue, 07 May 2013 13:15:10 -0400, Tom Biasi <tombiasi@optonline.net
wrote:
On 5/7/2013 8:52 AM, Uncle Steve wrote:
As I understand it, volts are sort of like the size of the pipe;
amperes are like the pressure or the rate of flow, and power is the
throughput. Of course it isn't plumbing and there isn't any water.
Regards,
Uncle Steve
Even with water, pressure and rate of flow are not the same thing.
Power is the rate of doing work.
The length of the pipe divided by the diameter is proportionally
equivalent to resistance.
Volts equates to pressure
Current equates to flow rate
...Jim Thompson
I thought he might look it up himself Jim
;-)
...Jim Thompson
--
| James E.Thompson | mens |
| Analog Innovations | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice
480)460-2350 Fax: Available upon request | Brass Rat || E-mail Icon at http://www.analog-innovations.com | 1962 |
I love to cook with wine. Sometimes I even put it in the food.
D
Daniel Pitts
Guest
On 5/7/13 5:52 AM, Uncle Steve wrote:
Ohms are like 1/(pipe size).
Watts are work performed.
Sans quantum and gravitational effects, electricity is very much like a
electron fluid. There are differences, but it is a useful comparison for
intuitive reasoning.
Amperes are like flow-rate.
Ohms are like 1/(pipe size).
Watts are work performed.
Sans quantum and gravitational effects, electricity is very much like a
electron fluid. There are differences, but it is a useful comparison for
intuitive reasoning.