08-28-2015, 03:50 PM
http://www.nostalgiaair.org/pagesbymodel...017623.pdf
I'm still figuring out the math involved in calculating wattage on power resistors, so please bear with me. The schematic shows the voltage going into R14 is 250v. The voltage going out is 210v, so that's a voltage drop of 40v. The resistance of R14 is 1500 ohms, so amperage is V/R=.02666?
P=R(I squared), so P=1.06? Wattage should be three times the calculated value, so I need at least a 1500 ohm 3 watt resistor? Closest I have to that is a 1200 ohm 5 watt, so I guess a visit to the electronics store is in order.
Am I even close to correct here? What is currently in the radio looks to be a 1000 ohm wire-wound (possibly 10 watt) resistor?
Somebody with some math tutoring patience want to straighten me out here?
Also, what is the wattage on flex-ohm resistors? Or is that a function of length?
I'm still figuring out the math involved in calculating wattage on power resistors, so please bear with me. The schematic shows the voltage going into R14 is 250v. The voltage going out is 210v, so that's a voltage drop of 40v. The resistance of R14 is 1500 ohms, so amperage is V/R=.02666?
P=R(I squared), so P=1.06? Wattage should be three times the calculated value, so I need at least a 1500 ohm 3 watt resistor? Closest I have to that is a 1200 ohm 5 watt, so I guess a visit to the electronics store is in order.
Am I even close to correct here? What is currently in the radio looks to be a 1000 ohm wire-wound (possibly 10 watt) resistor?
Somebody with some math tutoring patience want to straighten me out here?
Also, what is the wattage on flex-ohm resistors? Or is that a function of length?
Charlie in San Antonio
