Author Topic: Power Supply OVP Protection  (Read 1766 times)

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Offline echen1024Topic starter

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Power Supply OVP Protection
« on: July 13, 2014, 06:54:43 pm »
Hi,

So I have designed an HV supply with the Ultravolt modules, which output a 0-2.5v signal proportional to the output signal. For OVP protection, I have a comparator configured as a discriminator, with the reference divided into the non inverting pin of the comparator, and the output signal into the inverting pin. Thus, when the output is above the reference, the comparator pulls the output low and sinks the secondary reference, thus pulling the HV out low.

In this circuit, once the voltage is lowered, the HV out is enabled again, and operation returns to normal. I want it to require a hard reset before the output returns to normal. Anyone here have any suggestions?

Thanks.
I'm not saying we should kill all stupid people. I'm just saying that we should remove all product safety labels and let natural selection do its work.

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Offline Rerouter

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Re: Power Supply OVP Protection
« Reply #1 on: July 14, 2014, 10:19:01 am »
add some biasing to make it more of a schmitt trigger, (diode and resistor adding into the signal to make it stay higher than the reference,) that way when it trips it will stay tripped,
 

Offline rob77

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Re: Power Supply OVP Protection
« Reply #2 on: July 14, 2014, 10:30:53 am »
make an RS flip-flip out of a comparator - i did a over-current protection with hard reset exactly that way (for H-bridges - CNC).
so in fact one comparator as RS flip-flop - it's output pulling down the reference and a second comparator watching the output voltage and triggering the RS. + a button to reset the RS flip-flop of course - to manually return back to normal.
 


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