I'd like to use some solid state relays to turn on and off a
high voltage, low current DC inductive circuit (120-150VDC, 20-60ma). The SSR would only be switched on and off at a maximum of once every few minutes-- it would not be used for signaling.
(EDIT: Details about the SSR added below)
The specific SSR itself is a Fotek SSR-25 DD-- the DC 25A model sold here, rated between 5-220VDC and up to 25 amps. It's definitely a counterfeit, however, so it can only be trusted at up to around 10 amps according to my research (AC counterfeit versions were reviewed well here and here; I'd expect the DC version to have similar results, but I haven't found reviews for the DC version specifically). I can't seem to find a datasheet even for the "real" component, perhaps because Fotek never manufactured one named SSR-25 DD. The Fotek DC to DC SSR datasheet is here, rated up to 10 amps load for the 220VDC version.
Since I have such a low current requirement (60ma max), I felt comfortable enough to test these out for how inexpensive they are and spent $10 on a few after I originally asked this question. I will post results of my tests for posterity later.
The load is inductive. I've read about inductive AC loads potentially having issues with SSRs depending on the type of SSR, but I don't see anything about inductive DC loads thus far. This leads me to believe the issue must only be with AC circuits due to AC modulation, but I'd like to be sure.
1. The first question is simple-- would an inductive DC load have any issues running through an SSR?
The second and third questions are in regards to the signaling that will pass through the load side of the SSR after it is switched on. The circuit will pulse off and on at a speed of up to 45 modulations per second (45 baud, or up to about 1 modulation per 22ms; also remember that this signaling is being reliably generated by another component on the circuit, not the SSR).
2. If an SSR is rated to operate a load between certain voltages (5-220VDC in this case), when the circuit modulates between 0 and n volts, would the SSR effectively turn off and on even though the control circuit has never turned off, thus introducing a delay in each signal modulation?
3. Would an SSR having an inductive DC load modulating at a frequency like this cause any problems, particularly a delay or distortion in signaling?