[Test-Equipment] Question Regarding Fluke 8050A

[David]

I think the simple way would be to use a small solid state relay
powered from the DC side after the switch to control the second
transformer.  Alternatively leave the auxiliary transformer powered
and switch the secondary side.

This brings up something I have wondered about; is it best to switch a
transformer using a zero crossing switch or switch it at the peak of
the input voltage?  With a zero crossing switch, the transformer will
see a peak flux higher than normal but if switched at the peak, the
surge current into the secondary will be maximum.

On Wed, 3 Jun 2015 14:34:17 -0400 (EDT), you wrote:

>A good suggestion.
>
>With another transformer, I'll need a way to turn its output off.  The 8050A's transformer is "on" anytime it is plugged in.  The + and - lines from the rectifier are switched on and off with the power switch so I'll need to add something to turn on and off the new power supply.  More stuff to add...
>
>I plan to see if this is all going to work by powering the LED array with an external supply.  If that works, then great, but if not, I think I'll resort to normal 7-segment displays and dropping resistors.
>
>Thanks again,
>Barry - N4BUQ