I have an electronic transformer (120v, 60Hz to 11.6V, 20KHz) designed for landscape lighting. http://www.cast-lighting.com/__userfiles/file/mini-trans-prod-sheet.pdf

When I tried to test the low voltage side with a volt-meter (under no load) I read 0 volts.

When I applied a 35W load, I read the correct 11.6v.

I have two questions:

Is it always the case that you must apply a load to this type of transformer to measure voltage?

Am I able to measure load on the secondary using a clamp-on amp-meter. I was wondering if the 20KHz current requires a different test.

Thanks.

 

Hi Steve,

It would help if you kept your question to the one thread. I've just replied to your other related thread and initially missed this one.

The device you are using may well require a load to be connected to enable correct operation.

I'm also not sure what is the usable operating frequency range for your clamp on current tester. Over 20kHz may be beyond the measuring capability - particularly as it may be intended primarily for use at mains frequency.

 

The spec sheet says it requires a minimum load.

I would strongly doubt your clamp-on ammeter would be able to do useful measurements at 20 kHz. I have three such instruments and their stated bandwidths are 400, 500, and 1000 Hz. For measuring 20 kHz currents, you're getting into the realm of expensive scope probes for current.