11-06-2014, 03:42 PM
The valve heaters and dial bulbs chain is a 200 ma chain in total, regarding R25 the two 100 ohm resistor sections across the dial bulbs will dissipate approx .36 watts each, the 1k ohm section will dissipate approx 10 watts, the 130 ohm section will dissipate approx 5.2 watts.
Regarding R24, the 450 ohm section will dissipate approx 18 watts and as a guess the 300 ohm section will dissipate approx 5 watts, I'm assuming that the 450 ohm section is part of the valve heaters/dial bulbs chain and that the 300 ohm section is the rectifier limiter.
The above is based on normal operation with 230 v mains input once everything has warmed up.
You might want to factor in what might happen if one of the valve heater goes open circuit...I didn't get that far.
I don't know why I wrote this..
Lawrence.
Regarding R24, the 450 ohm section will dissipate approx 18 watts and as a guess the 300 ohm section will dissipate approx 5 watts, I'm assuming that the 450 ohm section is part of the valve heaters/dial bulbs chain and that the 300 ohm section is the rectifier limiter.
The above is based on normal operation with 230 v mains input once everything has warmed up.
You might want to factor in what might happen if one of the valve heater goes open circuit...I didn't get that far.
I don't know why I wrote this..
Lawrence.
