Voltage increase in powersupply


I have a basic question on power supply circuit(take example of F5 or F5Turbo power supply circuit). It is stated that you need 18V secondary voltage to get 24V output, also there is a voltage drop across diodes.
How does voltage increase happens in F5 power supply circuit?
Last edited:


Paid Member
2007-09-15 8:14 am
There is no voltage increase. 18 volts AC is correctly quoted as an rms value. This means that the peak of each tip of the sinusoidal AC waveform is actually 18 multiplied by root 2

Vdc = Vrms * √2

This is the DC voltage that you see across the reservoir capacitors. The diodes do drop around 1.4 volts in total.