[Amps] Meaurements

[Steve Thompson]

A couple of measurements I made in a spare hour:

Philips 330uF 400V electrolytic (about 2 yrs old). I measured without dc 
bias on the cap - series resistance at 2MHz is a few tenths of an ohm, 
rising to about 1 ohm at 50MHz. At these resistances the network 
analyser (HP8714C) is not at its most accurate, but it reads a 1 ohm 
resistor to within 5% over the range, so I doubt the figures are 
massively out.

A couple of microwave oven transformers. I lifted the 'ground' end of 
the ht winding on both and put them on hipot. One (much bgger than 
standard) is happy at a prolonged 10kV. I put some Kapton tape under 
where the wire comes out on the other, and it's good to 8kV+. In other 
words, both appear suitable for normal use with a bridge rectifier. I 
know they have their limitations, but given they cost *nothing* it's 
good value for money! I couldn't recommend using a floating winding 
without the hipot test, but it's clearly worth the effort of trying.

Steve