BBS Coil question

[bklein]

Ok, interesting. I'm out of town for a few days but the unsoldered connections are what are left over after connecting the coil wires.

[Skippy]

Interesting point: The pre-amp is powered by a full-wave bridge rectifier, whereas the meter gets its power from a two-diode rectifier, such as is found in centre-tapped transformer power supplies. The DC smoothing capacitors are small ( a few microfarads) as the AC frequency is high, and the DC current drain is low.