Regulated PSU question

[athos56]

So I made two of Janneman's T-reg boards and I have a few questions about the rest of the supply. I originally had a C-LC-RC PSU planned for my kt-88 amp. The choke was 18h made by Electrprint and the last cap was going to be one of those big 600uf / 500v ASC caps. Now with the regulator is there any reason to have a choke or large cap in the psu? Or Should I keep the choke and cap and just run a C-LC-Treg? (4.7uf - 18H - 600uf - Reg) Thanks for your help. If it helps my Power transformer is rated for double my expected idle current draw of aprox 100ma.

[SY]

The choke is a nice thing to keep ripple currents low. The big cap on its other side is overkill; 40-100uF is big enough if you're using the reg. To be sure, model your raw supply in PSUDII, then see if the ripple voltage ever causes the voltage to go low enough to drop out the regulator. Run the sim at both nominal and at 10% below normal mains voltage (you can do that by reducing the unloaded secondary voltage by 10%).

[athos56]

I'll do as you suggest, removing the large cap saves me a lot of space. The other caps I have are 50uf motor runs which should work well. Should I put one after the regulator, or take the B+ from the reg's output??

[DougL]

To add to what SY was saying, I would also run PDUDII at 10% over nominal to make sure you are not going to over-voltage a cap.

Doug