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by MrAl
Sat Jan 19, 2002 2:26 am
Forum: General Discussion
Topic: TV Flyback Transformers
Replies: 7
Views: 2085

Re: TV Flyback Transformers

Hi again,<p>Does anyone know the max voltage that can appear across a standard 1/4 or 1/2 watt carbon resistor? If we allow 250 volts max across a single resistor, we need 80 resistors in series to get up to a max measureable voltage of 20,000 volts. The string would have to be carefully arranged me...
by MrAl
Fri Jan 18, 2002 11:10 am
Forum: General Discussion
Topic: TV Flyback Transformers
Replies: 7
Views: 2085

Re: TV Flyback Transformers

Another idea is that the winding with the highest resistance is probably the high voltage winding due to many turns. Also, since these things can put out over 20kv it can be a safety hazard. I saw a high voltage probe built one time with a string of series resistors. The values are selected to drop ...
by MrAl
Sun Jan 13, 2002 8:01 am
Forum: General Discussion
Topic: ac dimmer
Replies: 12
Views: 3676

Re: ac dimmer

Hi there,<p>A really nice way to drive the triac is with a zero crossing detector, delay circuit, and one shot. At the zero crossing, the delay circuit starts timing though 1/2 of the AC sine wave cycle. At the point you set it to trigger, the one shot applies a pulse to the triac gate which turns i...
by MrAl
Fri Jan 11, 2002 5:58 am
Forum: General Discussion
Topic: DC to DC voltage doubler
Replies: 4
Views: 1786

Re: DC to DC voltage doubler

Hello everyone, nice to see the forum is up and running again after such a long delay.<p>My idea is similar to Chris's, except you only use one capacitor and one DPDT switch. When the switch is, say, 'down', the capacitor is in parallel with the 2.4 volt battery which charges it to 2.4 volts. When t...