electronic transformers - Electricians Forum | Electrical Forum | An electrical forum for electricians in the UK

11-09-2007

what are they
how do they work
ho do you tests these are electrically safe - flash test etc
anyone got any info on em

21-09-2007

They're switching converters. The AC input is rectified and smoothed, a PWM pulse train is then driven through a small flyback transformer. A feedback winding is then used to estimate the voltage on the low voltage side of the transformer. More expensive converters will use an opto-isolator to determine the voltage on the low voltage side of the transformer.

They're sensitive to high voltages, so don't do flash tests on them.

26-09-2007

SteveyG thanks for the info , i did flash test them and they failed so i guess 1500 vac at 5 ma did these no good at all.

Quote:

Originally Posted by SteveyG

They're switching converters. The AC input is rectified and smoothed, a PWM pulse train is then driven through a small flyback transformer. A feedback winding is then used to estimate the voltage on the low voltage side of the transformer. More expensive converters will use an opto-isolator to determine the voltage on the low voltage side of the transformer.

They're sensitive to high voltages, so don't do flash tests on them.