Ac voltage regulator

[timmy]

Originally Posted by Yamamaya42

1k on the filament transformer places no noticeable load on it at all, especially with the heater being 3.4 ohms, with the CRT unhooked, the transformer and resistor should hardly get warm at all, and all power would go the crt when hooked up and adjusted right.

I know with the resistor in series the trans won’t get hot I’m not worried about that I’m worried about the crt heater opening if the resistor don’t react quick enough the heater will open.

[timmy]

This crts heater does not glow at the proper voltage

[timmy]

Ok 100 ohms was not good so I tried 200 ohms not good then tried 147ohms and I’m now getting.430v which will work maybe I’ll try to raise it alittle bit more to get it close to .52 or .53v the 100 ohm had a slight surge seeing the heater glow so that was not good.

[timmy]

The reason for all this is I managed to get a decent b&w picture on the pilot tv it’s a bit smaller then the green but it’s bright and clear so I needed to get this voltage right if it were to be played for any length of time. This crt is bearly used and I have a spare and should last, made in Germany.

[timmy]

Well I set up resistors for the target voltage which I had but I was using dc voltage so ac requires a lower ohm resistor 55 ohms for ac and about 150 for dc to reach target voltage that’s a big swing. Correction I screwed up it’s 143 ohms had to put 2 1/2watt resistors in series to get 1 watt brings voltage to .503v resistors get hot but not burning hot.