Unregulated power supply

[Niko58]

Hello, I'm in the process of designing a PCB for a simple dual polarity unregulated power supply and I have a question regarding zones and traces. The PSU is designed to supply 4A and 40V on each of the two rails. There are two 10mF capacitors implemented to avoid ripple. So through each of the caps there will be 4A of current and I chose the width of 2mm and did quite a thick zone around the cap.

My question is, do you think it's okay to use zone or will it affect the current too much, and is 2mm enough or should I go for more sience it's really huge capacitors?

Thank you for your help, I really appreciate it.

Niko

 

[rayma]

The peak to peak voltage ripple is approximately equal to:

(I in Amps) / ( 2 x (C in Farads) x (line frequency in Hz) )

Or you can experiment with calculators. You have to decide how much ripple is acceptable at full
current output, it's several volts now. You may need more than 10,000uF for the 4A current.
Be sure to choose high ripple current capacitors for this purpose. The more pcb copper the better.

Online Calculator .:. Linear Power Supply Designer
Smoothing and Filter Capacitor Calculator - ElectronicBase

 

[Vovk Z]

You may use all maximum possible surface area for wires. There is no need to make them thin.

 

[lcsaszar]

The voltage does not play any role, the ripple percentage depends on the load current and the capacitor. I wouldn't use a PCB for this much current; point-to-point wiring is better. I use a 105mF capacitor for 2.4A load. There are short wires from the 25A rectifier bridge to the screw terminals of the capacitor, and another pair of wires go from the capacitor to the load. Ripple is still very big, so I use a 0.47R ceramic resistor and another capacitor at the load (C-R-C filtering).