LED , Meanwell , Typhon and a circuit question

[oreo57]

[quote="pebe"]I'll ask again!

Put a 100K resistor in series with the DIM+ pin, ie. between 9V battery+ and DIM+. Do you still get same output as without the resistor?
[/quote]
Only have a 1K resistor handy..but it is dimmer between bat and bat/resistor in series.


[quote="pebe"]

If not, what is the voltage a) across the 9V battery, and b) between DIM- and DIM+?[/quote]

Using a 1K resistor:
V Bat= 7.57 V
V between Dim- and Dim + after the resistor 6.08
and 1.5V between ends of the series resistor

Using a 10k pot:
I get @10 k.. dimmer light.. 7.57 @ bat.
2.59V between Dim- and Dim +
and 5v between ends of the series resistor

[pebe]

[quote]Using a 1K resistor:
V Bat= 7.57 V
V between Dim- and Dim + after the resistor 6.08
and 1.5V between ends of the series resistor[/quote]

That’s what I wanted to know. So the DIM+ pin is drawing 1.5/1000 = 1.5mA. And that is at an applied 6.08V. It’s probably going into an NPN bipolar, and that would agree with the fact that (according to the ELN spec) you get no output for the first 1.1V input. That being so, the current with 10V applied would be 1.5mA x (10-1.1)/(6.08-1.1) = 2.68mA

That’s too much for a simple integrator, so a buffer will be needed., it would use the 5V PWM signal (to avoid any possible problems of using the 10V PWM) and combine an integrator with a X2 amplifier. The attached circuit should do the trick.

R1 and C1 deliver an analogue voltage of between 0V and 5V - depending on the PW duty cycle - to the non-inverting input of the opamp. The pulse rate of the Typhon is not given, but the 0.5sec time constant given should be OK. The loading on the Typhon is negligible.

R2 and R3 give the amp a gain of X2, so what appears at the opamp output will be an analogue voltage of between 0V and 10V depending on the PW duty cycle.

The maximum output for the CA3140 shown is 10mA so it can cope OK with the current required by the ELN. But in common with most opamps there is an overhead for the output voltage of about 2V. That means the supply voltage must be 12V minimum (you already have a 12V supply feeding the Typhon). In worst cases the overhead may be up to 3V so if you cannot get 10V out of the amp, it is cheaper to get a 15V power supply than to go for a rail-to-rail output opamp at considerably higher cost.

Any equivalent opamp can be used, provided it has a FET input that can accept input levels down to 0V level. JFET or bipolar inputs cannot.

I hope that sorts out your problem.

[oreo57]

Yes and no.. It gives me another way but creates the same solution of using another power tap point. I guess that is just the way it is though..
(more background for refernce and adrunos way of doing the 10V analog)
[quote]Did what I said I wasn't going to do.. Pulled the LCD off the main board. Underneath on the board there are 4 NPN transistors feeding the 10V PWM. (BC549)
W 1800Ohm 5% resistors.[/quote]


[quote]Also on the board there are 2 voltage regulators (I will assume 1 for 10V bus and another for 5V buss..[b]LM7805A[/b])[/quote]

http://playground.arduino.cc/Main/Regul ... ageBooster
Actually don't think this would give me a variable output but I found it here:
for your FYI:
http://forum.arduino.cc/index.php/topic,17548.0.html
[img]http://playground.arduino.cc/uploads/Main/RegVoltageBoosterSchematic.jpg[/img]
I really appreciate your time. I suppose there is no simple non-powered way to boost the mA out of my little passive circuit??? Such as another r/c circuit such as this:
http://www.ehow.com/how_8780713_increas ... iodes.html

I KNOW I'm beinfg stubborn re: something as simple as tapping the 12V wall wart.. but that is the fun of this..

[pebe]

[quote]I really appreciate your time. I suppose there is no simple non-powered way to boost the mA out of my little passive circuit??? Such as another r/c circuit such as this:
http://www.ehow.com/how_8780713_increas ... iodes.html

I KNOW I'm beinfg stubborn re: something as simple as tapping the 12V wall wart.. but that is the fun of this.. [/quote]
No, there is no way of boosting the current in a passive way. You cannot create energy and you cannot get a quart out of a pint pot.

The problem with a simple integrator is that you need a time constant at least 10 times the waveform period. With a passive RC filter the resistance will be in series with the 3.3K input resistance of DIM+ so must be kept small – probably less than 100ohms. That means a capacitor that is impracticably large.

There is the possibility of using an LC circuit because the resistance of the inductor would be much smaller, but it would depend on the frequency (repetition rate) of the PWM and whether the Typhon 10V output could supply enough current.

You might like to check the output current. Connect the 10VPWM output direct to DIM+ and ground of Typhon to DIM-. Then adjust Typhon for max pulse output. If you get full output from ELN then an LC filter is a possibility.

Now for the frequency. I notice from your earlier postings that you do not have a ‘scope. This link will get you free software that converts the soundcard in your computer into a simple scope.

http://www.zeitnitz.de/Christian/scope_en

It will show you what waveforms are present, and their amplitudes. But because it is capacitor coupled it cannot tell you the DC level of the waveform, ie. which part of the waveform is at ground level. But this scope also has a spectrum analyser feature that can tell you what the frequency is.

If you would care to try it to find the frequency, we can take it from there.

[oreo57]

Yes, I remembered Ohm's law after posting about the "Free lunch"..
anyways my VOM has a frequency section ( I bought it to dabble in crossover building for speaker systems)
On hooking it to the 20Mh range I got .917 Mhz on the 5v PWM.. Zero on the 10..
Yes the 10v PWM is approx. full on at 100%.. still not sure how to defeat the inverted PW part using an L/C circuit..........unless you were referring to substituting an inductor for the R and still using the V doubler circuit..


will be installing the software for the O-scope soon..and thanks.. again.......

EUREKA.. sort of..substituting an inductor for the resistor (L/C filter) and using the same circuit on the 5V line actually will light and dim the Meanwell driver..
One catch, I have the opposite problem as you will see:
100%=9.61V (close to full on)
88%=9.59v
75%=9.58V
63%=9.56V
50%=9.53v
38%=9.5v
25%=9.45v
13%=9.34V
.26mH many turn toroid choke..

[oreo57]

BTW: Bitdefender is blocking my browser from going to the program download for the scope (bitdefender cloud protection, page is unsafe)..............

[pebe]

[quote="oreo57"]BTW: Bitdefender is blocking my browser from going to the program download for the scope (bitdefender cloud protection, page is unsafe)..............[/quote]
Sometimes my antivirus says a file I want to load is faulty. If I can trust the sender I over-rule the antivirus. I have never downloaded a virus as a result.

I can assure you that program is virus-free because \i have downloaded it. Trust me, overrule Bitdefender.

[pebe]

[quote="oreo57"]Yes, I remembered Ohm's law after posting about the "Free lunch"..
anyways my VOM has a frequency section ( I bought it to dabble in crossover building for speaker systems)
On hooking it to the 20Mh range I got .917 Mhz on the 5v PWM.. Zero on the 10..[/quote]

That doesn't make sense to me! I expected it to be in the range 50Hz to about 5kHz.
"zero on 10.."? What is this?

[quote]Yes the 10v PWM is approx. full on at 100%.. still not sure how to defeat the inverted PW part using an L/C circuit..........unless you were referring to substituting an inductor for the R and still using the V doubler circuit.

EUREKA.. sort of..substituting an inductor for the resistor (L/C filter) and using the same circuit on the 5V line actually will light and dim the Meanwell driver..
One catch, I have the opposite problem as you will see:
100%=9.61V (close to full on)
88%=9.59v
75%=9.58V
63%=9.56V
50%=9.53v
38%=9.5v
25%=9.45v
13%=9.34V
.26mH many turn toroid choke..[/quote]
These figures don't make any. Wait till you get the scope software working and try again.

[oreo57]

Re: the VOM frequency.. Yes that is questionable since I am having some issues remembering exactly how to use that aspect of the meter (works fine for impedance though)and the low bat warning is on......
I did write to the author of the software just so he is "aware" of the Bitdefender freak out.. I [quote]This duration or period is the inverse of the PWM frequency. In other words, with [b]Arduino's PWM frequency at about 500Hz[/b], [/quote]
http://arduino.cc/en/Tutorial/PWM
Adruno's PW is not that high...

As to the voltage figures... they are what they are.. and in practice it actually does dim and light.. but in a very "subtle" manner.. Don't ask me how..

[oreo57]

[quote="oreo57"]Re: the VOM frequency.. Yes that is questionable since I am having some issues remembering exactly how to use that aspect of the meter (works fine for impedance though)and the low bat warning is on......Maybe it was .917kH which is 917Hz isn't it?
I did write to the author of the software just so he is "aware" of the Bitdefender freak out.. I [quote]This duration or period is the inverse of the PWM frequency. In other words, with [b]Arduino's PWM frequency at about 500Hz[/b], [/quote]
http://arduino.cc/en/Tutorial/PWM
Adruno's PW is not that high...

As to the voltage figures... they are what they are.. and in practice it actually does dim and light.. but in a very "subtle" manner.. Don't ask me how..[/quote]

[oreo57]

10pwm
@40%
straight out of typhon
[img]http://www.qualiteitems.com/images/10at40pcttone.bmp[/img]
5pwm
@40%
straight out of typhon
[img]http://www.qualiteitems.com/images/5at40notone.bmp[/img]

[pebe]

So the frequency is about 1kHz - but the voltages are irrational.

10pwm gives 1.35vpp and 5pwm gives 1.8Vpp ? It's a nonsense.

[oreo57]

[quote="pebe"]So the frequency is about 1kHz - but the voltages are irrational.

10pwm gives 1.35vpp and 5pwm gives 1.8Vpp ? It's a nonsense.[/quote]

I don't think the V is "calibrated".. in any of these bmp's and should be ignored..

5V PWM w/ my filter (using the Resistor, not choke)

[img]http://www.qualiteitems.com/images/5vpwmfilteredOhm.bmp[/img]
5V @ 70% out NO filter..
[img]http://www.qualiteitems.com/images/5pwm70pct.bmp[/img]

Having internet issues presently.. and many more important projects.. also that Scope software is a "trial version" as well as I have no clue what I'm doing AND am worried about blowing out my sound card.. bear w/ me..
USING Choke in place of resistor in R/c circuit...5V doubled output..30% PWM

[img]http://www.qualiteitems.com/images/5pwmwl30pct.bmp[/img]

[oreo57]

[quote="pebe"]So the frequency is about 1kHz - but the voltages are irrational.

10pwm gives 1.35vpp and 5pwm gives 1.8Vpp ? It's a nonsense.[/quote]

I take it you are adding the "spead".. as I mentioned the program has a "click to known voltage" to calibrate.. but I just ran "as is" for a wave comparison..

rounding would give you a 1:2 ratio.. 1V vs 2V which would make some sense..

[pebe]

Are you using the 'Zeitnitz' software?, because when I tried it I could get a display anything like yours.