This is for a regulated power supply that I am building.
Instead of single diodes, I intend to use a bridge rectifier to convert the transformer voltage to dc.
My mains is 120 v ac rms, and my transformer is
115 v // 20 - 0 - 20 volts. I intend to limit the current to about 3.5 amps.
The transformer is very rugged, and guaranteed for up to 4 amperes of current.
For a 20 volt ac rms input voltage, and a maximum dc load of about 3.5 amps, how big of a diode bridge would be needed?
I'm using about 4,700 mfds of capacitance as filters, immediately after the rectifier. Since current leads in a capacitor, I am thinking that the moment power is applied, the capacitors will act as a short, and the current will max out, at least for the first time constant, until the capacitors start to charge. During this brief period of time, won't the current be alot higher than the 3.5 amps that the circuit will see when loaded down while in use?
Because of this, should I use a bridge that is rated much higher than 4 amperes?
Or is such a brief surge in current not going to really matter to the diodes in the rectifier?
Thanks in advance for any replies.