01-04-2022, 12:39 PM
Thanks, Terry. I think I may have one of those FW bridge rectifiers here yet too.
But I'm thinking of going with plan A first to see if I can get 135v out of the B supply on the existing design.
For that, I need to borrow your math skills again...
What would the total resistance needed be for the two voltage divider resistors to get to 135v? For 90v you had figured 10K.
Using this calculator: https://ohmslawcalculator.com/voltage-di...calculator
and entering 140 as the voltage source, R1 (or from the + side of the 47 mfd to B +) would be a 50 ohm, and R2 (or between B + & B -) would be a 10K ohm resistor to get 139 volts output.
Now obviously that's without a load so it probably will drop under 135 in circuit but may be enough to power the radio.
But I'm thinking of going with plan A first to see if I can get 135v out of the B supply on the existing design.
For that, I need to borrow your math skills again...
What would the total resistance needed be for the two voltage divider resistors to get to 135v? For 90v you had figured 10K.
Using this calculator: https://ohmslawcalculator.com/voltage-di...calculator
and entering 140 as the voltage source, R1 (or from the + side of the 47 mfd to B +) would be a 50 ohm, and R2 (or between B + & B -) would be a 10K ohm resistor to get 139 volts output.
Now obviously that's without a load so it probably will drop under 135 in circuit but may be enough to power the radio.
Greg V.
West Bend, WI
Member WARCI.org
