If you really want to go the relay route, you'll probably need to go to a
vacuum relay

See

http://www.jenningstech.com/ps/jen/p...?action=relays

I've been using one for a number of years for switching 1200V dc @ 0.5A and
have had no problems.

Coil voltages are normally 12 or 24VDC but I don't think they are available
in 5V



"Ian Bell" wrote in message
...
I am trying to select a relay for a delayed HT switch (which will also
discharge the HT when off). Most relays I can find have contacts rated at
250VAC which translates into a peak of about 350V. However, data is scarce
on what dc voltage these relays can switch. So far I have found only one
that gives a dc current versus voltage curve and that stops at 210V dc (and
200mA) and I really want to be able to switch up to 350V at up to 200mA.
The rest just give a dc voltage at max current value.

So, I am guessing that this problem has been faced before and there are
relays that are known to work fine in this application. Any
recommendations?

By the way I prefer a 5V coil.

Cheers

Ian