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boiss · 24th Oct 2006, 8:03 am

Hi Ed,
Unfortunately I dont have a variac, the only voltages that I could apply via a transformer are 6V and 110V, not a great deal of use. Another thing is the accuracy of the current reading I would obtain because unloaded the transformer only draws approx 10mA at 220V. I am unable to measure directly AC current, this value was obtained by measuring the voltage across a 68 Ohm resistor in series with the transformer (0.67V). Also I've no Idea what the value of "B" is.
I think that I will get hold of another one if I can and try and rewind it with 345 turns on each primary and a tapped secondary winding. I have seen one on ebay but there's still 7 days to go. As I said before the one that I have already will be used for the heaters. I intend to run the heaters on AC and play with the phase and balance the voltage across the heaters to reduce the hum. If it's not acceptable then it will have to be a stabilised DC supply with mega heatsinks. I guess it will keep me warm in the winter.
Mike.

24th Oct 2006, 8:03 am	#20
boiss Pentode Join Date: Jun 2006 Location: Malaga, Spain. Posts: 235	Re: Toroids as O/P trannies Hi Ed, Unfortunately I dont have a variac, the only voltages that I could apply via a transformer are 6V and 110V, not a great deal of use. Another thing is the accuracy of the current reading I would obtain because unloaded the transformer only draws approx 10mA at 220V. I am unable to measure directly AC current, this value was obtained by measuring the voltage across a 68 Ohm resistor in series with the transformer (0.67V). Also I've no Idea what the value of "B" is. I think that I will get hold of another one if I can and try and rewind it with 345 turns on each primary and a tapped secondary winding. I have seen one on ebay but there's still 7 days to go. As I said before the one that I have already will be used for the heaters. I intend to run the heaters on AC and play with the phase and balance the voltage across the heaters to reduce the hum. If it's not acceptable then it will have to be a stabilised DC supply with mega heatsinks. I guess it will keep me warm in the winter. Mike.