Hi
How to make current limit for PC supply, but not that kind that shuts down the supply. Something like small current sensing resistor, optocoupler that is connectet to error amplifier or somewhere else on driving chip...
When over current would occurred, opto would start to open and narrowed the gate pulses...
How to do that?
How to make current limit for PC supply, but not that kind that shuts down the supply. Something like small current sensing resistor, optocoupler that is connectet to error amplifier or somewhere else on driving chip...
When over current would occurred, opto would start to open and narrowed the gate pulses...
How to do that?
Try any opto with a good CTR (current transfer-ratio) of, say, ~100%. The CNY17-2 & CNY17-3 are a couple of good examples. You could use a transistor to drive the opto, but an op-amp would probably be better. Also, use an op-amp on the primary side coming off the opto as your signal-conditioning amp. This one will drive the deadtime pin.
As drawn current increases to the selected trip point, the circuit will insert additional deadtime until the "overload" condition is removed.
As drawn current increases to the selected trip point, the circuit will insert additional deadtime until the "overload" condition is removed.
You could, but your operation would be crude, at best. try a 0.01W 2-5W resistor in series with your (+) output and take the voltage developed across this resistor to drive your op-amp in differential fashion. Have that op-amp drive the LED-half of the opto.
Using op-amps will give you tighter control and allow some adjustability.
Using op-amps will give you tighter control and allow some adjustability.
Hi
Never mind uper one, what I tried to do was when there would be 0.6-0.7V on resistor, transistor would open and draw current from E to B and C.
Other one is better one. I don't think I can change R1 or R3, since at this point as it is, R1 would need to be low value as possible, but so is R3 too to react to lowest voltage cross resistor. Am I thinking this right?
I really don't want to use op-amp here if not necessary.
Never mind uper one, what I tried to do was when there would be 0.6-0.7V on resistor, transistor would open and draw current from E to B and C.
Other one is better one. I don't think I can change R1 or R3, since at this point as it is, R1 would need to be low value as possible, but so is R3 too to react to lowest voltage cross resistor. Am I thinking this right?
I really don't want to use op-amp here if not necessary.
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