PS cap FPIII

[Laudanum]

I was interested in knowing why the FPIII uses the BH "standard" 220uf 250V caps for the first two caps in the supply but then follows those with a 47uF 450 volt cap?    Why not another 220uf 250V cap like in Crack and Seduction.   Just curious in learning a little something here.

Thanks

[Grainger49]

The first two caps are in series, so they are in effect a 110uF@500V cap.  (the resistors in parallel with each 220uF@250V cap keeps the voltage across the caps properly divided and they bleed the caps when power is not applied) 

Bottlehead already stocks those for other kits and it makes it simpler for them to stock fewer parts.  They get a discount making larger orders of the same parts. 

[Laudanum]

Nevermind, I think I answered my own question.   The 220uf 250 volt caps are in series so actually the voltage rating is double to 500 volt ... I think.   Yes?

[Laudanum]

Thanks Doc, I actually figured it out while you were posting.

[Paul Joppa]

More specifically, the power supply is what's called a "voltage doubler". The winding is 160 volts rms; one diode and cap makes +200 volts, the other diode and cap are reversed to make -200v, for a total of 400v. The 400 volts is used in stock Foreplay and in the SEX amp.

The same winding is used with a fullwave bridge rectifier to make 200 volts, for Crack, Smack, and eXtended Foreplay. This way we do not need different transformers, and can buy them in larger quantities at a better price.

[Grainger49]

Thanks Doc, I actually figured it out while you were posting.

Doc didn't post.  But I appreciate being confused with Doc, I'm flattered.

[Laudanum]

Thanks Paul and you're welcome Grainger.