Just wondering what the rule of thumb is for de-rating solid state relays.
My "control" output from the Nak Ca-5 is 24V but the control transistor is just a 2sc3333 which is a 50mA max part. No big 250 Ohm power relays in store for that. I was thinking a solid state relay as they only need about 10mA. So, de-rating for a power amp load, 2X? 4X? I can't find much of anything on surge current for the relays. Price goes up a lot after the 25A relays.
My "control" output from the Nak Ca-5 is 24V but the control transistor is just a 2sc3333 which is a 50mA max part. No big 250 Ohm power relays in store for that. I was thinking a solid state relay as they only need about 10mA. So, de-rating for a power amp load, 2X? 4X? I can't find much of anything on surge current for the relays. Price goes up a lot after the 25A relays.
Hi
I'm not sure what you mean by derating.
SSR's have minimum and maximum ratings and you cant exceed either of them. You'll either risk damaging it or it just won't work.
It would be helpful if you could be specific about what you want the SSR to do.
Is it switching AC or DC (there are different types for each)?
What voltages and currents are involved?
Is it for speaker protection?
Did you have any particular type/part number in mind?
I'm not sure what you mean by derating.
SSR's have minimum and maximum ratings and you cant exceed either of them. You'll either risk damaging it or it just won't work.
It would be helpful if you could be specific about what you want the SSR to do.
Is it switching AC or DC (there are different types for each)?
What voltages and currents are involved?
Is it for speaker protection?
Did you have any particular type/part number in mind?
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AC, 125 V, to allow the preamp external trigger to power up the power amp. I have no way of knowing what the inrush current of the amp would be. The "rated" load of a 60W amp is about 4 Amps, and this particular amp has a 10A circuit breaker, but that is only relevant for picking the heat sink. Is a 25A SSR sufficient?
Hi
Sorry for the delay.
SSRs usually have a surge rating double the rated current for 10mS so a 25 A device would be more than adequate. If you could find a 10A or 15A unit, they would be fine and cheaper.
Sorry for the delay.
SSRs usually have a surge rating double the rated current for 10mS so a 25 A device would be more than adequate. If you could find a 10A or 15A unit, they would be fine and cheaper.
Looking at the SCR C106 datasheet, its peak surge capability is nearly 5 times its rated current. SCRs are used in SSRs.
Gajanan Phadte
Gajanan Phadte
I think you will find that they are triacs as they need to conduct in both directions. My information was based on SSR data sheets. Perhaps I should have said at least twice the nominal current rating.
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