09-03-2018, 08:21 PM
>How did you get to figure the diode would do the rest?
It's a highly guarded secret but since your a member I'll spill the beans.
So how it works is that the diode doesn't conduct during the negative cycle
of the ac voltage applied to it. It does provide abt a 40v drop or 125vac X .7=88vdc
You need abt 100v so it is slightly low but is within reason. I suppose if it seem too
low you could add a SMALL cap from the 1N4007 cathode to B- and that will boost
the heater voltage. If you want to experiment I'd start with a .01mfd or so. No
big eletrolytics.
It's a highly guarded secret but since your a member I'll spill the beans.
So how it works is that the diode doesn't conduct during the negative cycle
of the ac voltage applied to it. It does provide abt a 40v drop or 125vac X .7=88vdc
You need abt 100v so it is slightly low but is within reason. I suppose if it seem too
low you could add a SMALL cap from the 1N4007 cathode to B- and that will boost
the heater voltage. If you want to experiment I'd start with a .01mfd or so. No
big eletrolytics.
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!
Terry
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