The Resistive Power Supply
Friday, October 31st, 2008
When designing a resistive power supply, the value of the “dropper resistor” is obtained by taking 12v from 240v = 230v. This is the voltage across the dropper resistor.
Let us allow 20mA current through the dropper resistor.
The value of the dropper resistor is: 230/0.02 = 11,500 ohms = 11k5.
The wattage of the resistor = 4.6watts [...]
