Hi all,

I would like to discharge a electrolitic capacitor doing a shortcircuit between his pins with a resistor. I close the circuit to discharge the capacitor controlling it with a optocoupler controlled with a uC. I would like to open first the circuit which feeds the capacitor to avoid a shortcircuit in the feeding.

I would like to do that just using one optocoupler. Any idea?



Thank you!

 

What you are looking for is an SPDT (single-pole, double-throw) switch or relay. Very common in an electromechanical part, not so common as an optoisolator. What is the peak voltage across the capacitor, and the value of the resistor? Without this information, there is no answer. This might work, or it might burn up:

http://www.ixysic.com/home/pdfs.nsf/0/1D7C2FC89A5985B985256A2C006889F1/$file/Lcc120.pdf

ak

 

You might also consider an optoisolator with a triac/scr output. Trigger once and it conduits until current stops, then stops conducting until the next trigger.

https://www.digikey.com/products/en/isolators/optoisolators-triac-scr-output/904

 

You might also consider an optoisolator with a triac/scr output.

How would that prevent presenting a pseudo-short to the voltage source?

ak

 

thanks both for the answer

What you are looking for is an SPDT (single-pole, double-throw) switch or relay. Very common in an electromechanical part, not so common as an optoisolator. What is the peak voltage across the capacitor, and the value of the resistor? Without this information, there is no answer. This might work, or it might burn up:

http://www.ixysic.com/home/pdfs.nsf/0/1D7C2FC89A5985B985256A2C006889F1/$file/Lcc120.pdf

ak

with 170mA I can put a resistance low enough to discharge the capacitor in the time I need, so I think this option will be perfect, it's just what I was looking for

You might also consider an optoisolator with a triac/scr output. Trigger once and it conduits until current stops, then stops conducting until the next trigger.

https://www.digikey.com/products/en/isolators/optoisolators-triac-scr-output/904

It is a very elegant solution, but I will opt for the other because I save adding one more integrated, even though thanks for your answer, it is a device that I did not know and that will surely be useful in another situation