May 042012

A How-NOT-to-do-it guide

This Wave 2 owner decided that his PPG also requires a backlit display.
No problem so far. But the datasheet of the EL foil backlight stating that it need 200 to 250 volts AC obviously led to a very wrong decision:

What we see here is an AWG28 2-wire cable ripped off from some flat cable, soldered to the primary lugs of the mains transformer -or, in other words – directly to the 230 VAC mains.
The other end is connected to the EL foil behind the LCD. Even the cheapest alarm clocks from the 70’s running EL illumination from the mains had at least a protective resistor in series.


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