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Polarization Problem

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It really dont matter, i do like darlingtons but its a 6 pin package and to keep things tight it would be better with a 4 pin package like the one you found, then for even a better solution the Quad package would mean less chips as you get 4 in one package, i see the one you found is also in a quad package option.

What i would pick........the easiest i could source at the cheapest price........then im a cheap sod at times.
If you need 180 of these at close to a dollar it adds up quickly.

Pete.
 
The one I found I know is used on the SSR boards that the Grinch DIY board uses. So I know that it will work. Plus its ALOT cheaper. As long as you think it will open the gate on the Thyristor.
 
What is the voltage to the thyristor? AC? DC? how many volts?
 
I see no reason it wont work as the thyristor is only a logic level gate so should be no problem.

You can connect all the cathodes of the transistors to a common 5v+ rail and all the emitters to a thyristor each.
The leds will need an resistor on the anodes and the cathodes are connected to the led driver output pins.
 
What do you need a led for the opto has the led built into it, although you will not be able to see it if you want an indicator.

10K is a bit high, and what voltage do you intend to run the leds from.
I think the led driver can be used to limit the current the led draws but not sure so would add a RESISTOR to be safe.

Edit:- sorry i said led and it should have been resistor as in capitals now.
 
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Ah, No I would rather not have to power more LEDs. I already have 3 per channel. So your saying all I need is the OPTOs, No resistors, no LEDs to make it work?
 
NO........1 opto per channel and 1 resistor for the led in the opto per channel (i edited the last post)
 
Are you running 5 volt on the led side of the optos and if so how many optos will be ON at any one time, as all the leds will draw current, and then how are you supplying the 5 volts, if its a regulator it might not handle the current load.

See there is a lot of unanswered questions with your circuit so the answers are not black and white.

Here is a quick schematic that is not strickly correct as i just used the components i could find quickly to give the idea of where the resistors would go.
 

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I will never fire more than 2 OPTOs at the same time. It will be a regulator. but one for every 64 Channels. So they can handle the load. Im running everything (Grinch, OPTOs, and Thyristor Gate all at 5VDC. I have NO idea at all of how to wire this thing up. So im not sure. :p This OPTO stuff is all new to me.
 
If your SCR is driving LEDs tied to +5 DC it will not turn off once it has turned on.
Why don't you drive the LEDs from the LED driver? Not enough current?
 
Sorry ronv, again my failure to get alot of good info you yall.
The SCR (Thyristor) is pumping out 12VDC to my E-fuse. And that take alot of current. Because of the long distances
 
Ok if you are using 5 volt to the opto leds than 330 ohm would be as low as you can go but i would think 1K should be fine for the opto leds.

Your theory on lots of current for long distance is a bit flawed i think as the long wire distance will increase resistance and reduce current so might need a higher voltage to compenaste the resistive loss of current.

I think what Ronv meant was if you have a led powered by the scr then the scr wont turn off, where as if its only the Efuse then the circuit will be broken after it fires.......Or will it??? as the burnt wires could be then be shorted or fused together and overload the entire system if the scr is unable to switch off.
 
I built the circuit with LEDs and it does turn off. Took some time to figure out, but its posible :p And the E-Fuse can't be fused together, just the safety of how they are made. I understand now what he meant. I just ordered everything, and ill get some diagrams up here soon, and let yall know how it goes. THANKS SO SO SO MUCH guys
 
Lets all hope there is lots of smoke and fireworks in the right way with this circuit.

Good luck and hope it goes off with a BANG *****************

Pete.
 
OTPOs in and I'm testing. They work great, but here is the deal... it wont open the Gate on the Thyristor. Ive tired 5 and 12V. I had to put a big 15omh resistor on the gate in order to make it turn off. It worked great when hooked to 1.5-5V but now even though im reading 5V at the gate through to OPTO.... It still wont open with the resistor there.....
 
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Oh and also I put the 15ohm resistor on it because it kept firing on accident, by just me touching it, or hooking it up to the vga cable. I just tired it with a 1K resistor on the Gate, and it works great. But I know it will mess up as soon as I try to touch it.

So here is the deal, I can use a battery and open the Gate on the Thyristor, And I read 5V.
Now when I power the gate through to OPTO, even though I read 5V out, it drops to .10 at the gate? That make ZERO sense to me..... Is the OPTO not able to handle the Amps that is needs to over power the 15 OHM resistor on the gate? But that dont make any sense either....... hhhmmm

UPDATE: I didnt put the resistor to power the LED on the OPTO, and got 2.04V at the gate of the Thyristor. I gues there isnt enough Amps to open the gate. Any ideas?
 
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