Excel Sheet For Power Supply Calculation

Hi

Recently I've seen many threads here with people struggling with the basic calculations of linear power supplies. That's a pity I'd say as linear power supply design is--at least for low-power DIY audio needs--a simple task, once you got your head around a few formulas.

As the calculations required are repetitive and boring I decided to publish the Excel spreadsheet I put together to speed up the design task: PSUCalculator.xls

Based on several input values (such as transformer secondary voltage, filter capacitor values, output current and output voltage) it will calculate important parameters such as regulation headroom, regulator dissipation and transformer power rating.

I hope the short documentation will be sufficient for successful use of this spreadsheet--otherwise feel free to ask here and I'll give more information.

Samuel

Thank you, Samuel. That spreadsheet would certainly be useful for quick and dirty calculations.

I have also found the Duncan Amps PSU Designer II to be very useful.

Samuel,

thank you very much.

awesome and very useful calculator Samuel! :thumb:
Thank you very much!
-grant

Hi Samuel,
you've done a great job.
If you don't mind, I would suggest a couple of changes for even better results, particularly in calculating small voltage-high current power supplies. This is what I have in mind:

"Cell D7":

Change from "Voltage drop of rectifier diode, 1 V typical"
to "Voltage drop on rectifier diodes, 1.5V typical, 2V recommended for currents exceeding 2A".

"Cell D14":

Change from "Worst-case ripple before regulator, should be around 1 V"
to "Worst-case ripple before regulator, should not exceed 1V"

"Cell D16":
Change from "Worst-case headroom before regulator drops out, should be around 1 V"
to "Worst-case headroom before regulator drops out, should be minimum 1V"

"Cell B16":
Change from "=B6*SQRT(2)*(1-B4/100)-B7-B11-B14-B8"
to "=B6*1,3*(1-B4/100)-B7-B11-B14-B8"

(The shape of the mains voltage is never an ideal pure sinus wave, at least not where I live,
and power transformers tend to show a slight saturation at their rated power).

Regards,
Milan