Nombex Type 62 Cap/Res Bridge.

[pwdrive]

PF% = Power Factor.

Lawrence.

Thanks Lawrence, but I'm puzzled as to why that 100 Ohm variable resistor only comes into play on the 1uF range, and why the 'PF scale only goes to 70%, or what effect this setting would have on the null point of the dial. I won't know till I've got it working properly! (As it's a cap bridge I associated the term 'PF' to be pF - picoFarad, so thanks for clearing that up).

Really, this little project is yet one more diversion, which explains why it always takes an eternity for me to finish anything!

So far as I am aware the PF is proportional to difference between the impedance of the capacitor and it's reactance.
The test frequency is fixed so the higher the capacitance under test the lower it's reactance therefore the PF becomes more apparent and measurable.

I think a PF of 100% would suggest a perfect capacitor which doesn't exist.

Any corrections or additions to the above are welcome as my theory is a bit rusty...

The PF and Balance control will inter act, adjust both repeatedly for sharpest null then read off scales, it's a similar set up to the Marconi TF2700 bridge.

Lawrence.