18-09-2015, 04:12 PM
Well, as a result of all your help, I do believe we've cracked it!
Sorry Mark, although I understand the principal of the saturation test, I don't know how to connect a current meter in series on a transformer. Oops! embarrassing
Does it entail taking a current reading off the taps into which I am applying the voltage?
So in ignorance I just went for the 'matter of elimination approach' and I have established (I think) that winding 1 and 2 is just one winding with 7 taps - the primary. By keeping a constant 20v across the taps I measured the output on what was winding 4 and worked out that if taps 1 and 7 (see pic) are the start and end of the winding then winding 4 is a 4v heater winding (now re-labelled winding 3). The high voltage winding is 300-0-300v (now re-labelled winding 2) and the final winding is 2-0-2v.
To see if this was consistent with the Philips 795A I managed to find the Philips Service Manual online and all the valves are 4v heater types (FC4, VP4B, TDD4, PEN A4, 1821) and the maximum voltage across C2 is 275v.
Do you think the values I have calculated make sense?
Nick
Sorry Mark, although I understand the principal of the saturation test, I don't know how to connect a current meter in series on a transformer. Oops! embarrassing
Does it entail taking a current reading off the taps into which I am applying the voltage?
So in ignorance I just went for the 'matter of elimination approach' and I have established (I think) that winding 1 and 2 is just one winding with 7 taps - the primary. By keeping a constant 20v across the taps I measured the output on what was winding 4 and worked out that if taps 1 and 7 (see pic) are the start and end of the winding then winding 4 is a 4v heater winding (now re-labelled winding 3). The high voltage winding is 300-0-300v (now re-labelled winding 2) and the final winding is 2-0-2v.
To see if this was consistent with the Philips 795A I managed to find the Philips Service Manual online and all the valves are 4v heater types (FC4, VP4B, TDD4, PEN A4, 1821) and the maximum voltage across C2 is 275v.
Do you think the values I have calculated make sense?
Nick
