SONGLE Mini 12V DC Power Relay SRD-12VDC-SL-C voltage limit for quick on/off DC

I'm doing a photography project, where I want to wirelessly set off a series of old flashes (Vivitar 283) with staggered time delay.
These flashed are cheap robust and plentifull (I have about 10), but has a high voltage over the flash shoe of about 280V in the "worst" examples.

The time delay relay switches that are most common, cheap (by far) and simple, is the ones equipped with a 555 and the Songle relay mentioned in the heading.

The Songle has a max spec of 250V AC 10amp and 30V DC 10 amp.

The switching time for the wireless flash triggers is about 5 to 20 milliseconds (from what I can gather), with no continuous current.

My question is: will I be fine with such a short switching time even if it goes over spec?
Isn't the spec meant for continuous current (of AC or DC)?
Would 280V and whatever small amperage into the relay do immediate or long term damage?
Also remember in this particular application the relay is not going to see more than at the very most 10.000 actuations over it's lifetime.

It's a quick (when the relays arrive) and cheap experiment to do.
But is it worth bothering?
Or is there a better option?

There is much on the internet about doing this as a remote flash. You can probably use a MOC3020 opto isolator and keep everything electrically isolated from the logic circuits. Try something in the 200 Ohm range for the LED side of the isolator, it should get you in the ballpark. This is not a cheap solution but it is inexpensive, less then a buck each. If the connections to the LED of the MOC3020 get more them about a foot use buffers to isolate the arduino, cheap insurance:-)

When I did this years ago I just used SCRs for remote flash. If you want a sequence I would look at using 400 volt rated SCRs which are common and inexpensive. Gate trigger them using whatever you want for a sequence and timing. The SCR works well with the older flash units. The idea being is it fires, you get a flash and the SCR current drops to zero. The only issue is a flash which when fired the current does not drop enough to have the SCR turn off. I doubt that will be a problem with the old Vivitar 283 units.

Use a clock be it 555 derived or other to drive a counter like a CD4017 which could drive 10 flashes. Count to N with N = 10 and reset. The clock frequency determines the sequence rate. An NTE 5426 SCR should work. That or similar.


The MOC3021 sounds perfect for this application. 400 V rating so no problem there; you have complete isolation from the high voltage. 15 mA current to trip it.

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