I am trying to figure out is there is any rating on the maximum
switching speed on mechanical relays ...
I want to use dc current on these and
switch them possibly 1000Hertz or possibly 10,000Hertz.
Firstly, if the coil current is modulated at 1000 Hz, this is NOT DC
current
we're talking about. On every cycle, you'll generate some core heat
due to magnetization losses. This may be important. Smoke
is possible. Do not expect that 'normal' operating voltages are
sufficient, either
Secondly, the 'ON' position of the relay is achieved by hitting a pair
of parts together , and they either progress to hammer each other
out of shape OR they engage in elastic deformation. That elasticity
means there is bounce, and the 'ON' status is very much compromised
until the bouncing stops. This is the one, the only, item that a
relay
manufacturer is likely to specify about the short-time character of
the relay.
And third, the 'OFF' position usually is a long way from the 'ON',
so that sparks don't occur. If you expect 5 kV operation, or 50 mV
operation, the suitable delay-to-OFF time will be quite different.
Some small-signal (telephone) relays have impressive contact lifetime
with circa 50V stress; lower voltages have dirt-related reliability
issues, and higher voltages have wrath-of-Zeus related reliability
issues.
At 1 kHz your prospective device will hit millions of times per hour,
and contact life will be a major issue. Practical vibrators (I seem
to recall)
worked at tens of Hz.
The literature on this kind of application is heavily influenced by
Motorola
and relates to early car radios (which Motorola made); the oscillating
'relay' was called a vibrator, and failed as frequently as any of the
vacuum
tubes.