> Another subtlety to be aware of when doing this is the insulation between
> windings and core. If the core is grounded, as it should be, and one end
> of the series string is also grounded, the core at the high end of the
> string is experiencing twice the voltage it was designed for.
>
> In some configurations this is important and in others it is not. Just
> something to keep in mind during the design phase.
>
> Bill, W6WRT
Thanks Bill, and all. Seems as if I had forgotten some basic stuff!
This application is for low-voltage relays, through about 160' of cable,
which is still in a coil on the shack floor.
The two relays must draw a fair amount of current. I tested them, through
the rather light control line, with the power supply I had planned on using,
but the voltage at the other end was 19 volts, instead of 24.
I cobbled-up a power supply this AM using two larger 12 volt transformers in
series, which produce almost 30 volts at the supply end, and the voltage at
the relay end is now just above 24 volts when actuated.
I'd rather hit TR relays a little hard than not hard enough!
So, problem solved, thanks.
73, Barrie, W7ALW
>
>
>
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