Author Topic: Opto - Transistor Pulsing Circuit  (Read 14575 times)

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Re: Opto - Transistor Pulsing Circuit
« Reply #24 on: August 23, 2010, 13:45:20 pm »

I think i'll start with the first circuit even though it has an inverting signal, then modify the code from the micro controller to deal with it, if that doesn't suit me i'll track down an npn transistor to add to the circuit.
Oh why didn't you say that earlier?  ;D
You just have to change the HIGH and LOW values on input or output (if the optocoupler gets his signal from the mikrocontroller you can just switch the output to low when there is a pulse and to high when there is none)

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Re: Opto - Transistor Pulsing Circuit
« Reply #25 on: August 23, 2010, 13:52:19 pm »
haithar if i said that right away i wouldn't have learned as much :)

is the cap in the JLN circuit needed?
10k resistor still good?

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Re: Opto - Transistor Pulsing Circuit
« Reply #26 on: August 23, 2010, 14:28:46 pm »
yes you can use a 10k or something in that range. if you have 9k or 13k or something like this it should work.


the cap is not absolutely needed, but always good for stabilizing everything.

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Re: Opto - Transistor Pulsing Circuit
« Reply #27 on: August 23, 2010, 17:14:11 pm »
I will draw for you a good circuit... this evening...


The capacitor conected to drain and source is a must because this allow the transistor to switch of... otherwise you will aways see it warming a lot...

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Re: Opto - Transistor Pulsing Circuit
« Reply #28 on: August 23, 2010, 18:43:44 pm »
I do not know about the capacitor between d and s , perhaps somebody could find a link to more information and circuits showing this .

My circuit works , just make sure you put a 1k-800 ohm type resistor to protect from over on base of both transistors . I use cmos for everything using square logic , I simply love cmos cd4000 , unfotunately these cannot be salvaged since its too old but digikey has all of them for 25 cents each , most electronics stores also have them for 1$ each . Imo only capacitors should be salvaged , I cannot imagine myself being in a position where I look for small little components on old stuff and then unsoldering , only in a post-apocalyptic  world where all silicon ship makers were destroyed .

If someody wants an easy schematic he will have to suffer humiliation , that is the rule . My comment was adressed only to Donald , even if it was in the plural form .

Donald , you should stop being distracted by these trivial activities and return to your studies , mister engineer student .

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Re: Opto - Transistor Pulsing Circuit
« Reply #29 on: August 23, 2010, 20:54:00 pm »
Awesome thread donald! i am lost in this area too and this topic is shining some light.... i would throw some insight in too but most likely it would be off subject lol.

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Re: Opto - Transistor Pulsing Circuit
« Reply #30 on: August 23, 2010, 21:33:04 pm »
The thing about ordering components is I don't know exactly what I'm looking for, and then there is shipping time and the cost of the chips... if I can get something going without spending much, then I can order new components and make a fresh circuit once I know exactly what I need. I have no training in this type of thing at all, so sometimes I miss the obvious solutions when searching for what I 'think' might be a reasonable  approach...

Thanks for your help everyone, I should have something together tonight hopefully.

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Re: Opto - Transistor Pulsing Circuit
« Reply #31 on: August 24, 2010, 00:37:53 am »
wow I can't follow that, try neater