Frans: I have replaced the 1R - C-R-C - filter resistor by a 33R one (look at it - keeping in mind the voltage drop across it) and have connected the output to my Tektronix 465B.
I am not able to show you any variances on the output voltage!
The layout of this PSU seems to be quite o.k. then!
Best regards - Rudi
I am not able to show you any variances on the output voltage!
The layout of this PSU seems to be quite o.k. then!
Best regards - Rudi
Attachments
The "shape" of the ripple waveforms should look VERY different on the two Cs of the CRC.
Have another look.
If you can't see any difference in the shape, then 33r is still too small !!!!
Have another look.
If you can't see any difference in the shape, then 33r is still too small !!!!
Yes, it all depends on the current through R (and the voltage over as it is I * R). Also check Ft at '1 / (2 pi R C)' where C is the buffer capacitor, the -3db point should be considerably below 100Hz (I would say the 10 Hz is a nice target).
The point of this all is, by removing noise from the regulator input it (the regulator) will be able to do a better job. To see how this job is performed, you should load the regulator with a (as large as possible within the design limits of the PSU) dynamic load. Then you check the currents flowing in and out of the first and second capacitor (of the C R C) and there you will see large differences. Also you will see that the PSRR of the PSU has improved, the output/line regulation will only marginally improve (but there will be an improvement) and this is harder to spot (a FFT analyzer may be needed).
And you should load the supply with the approximate current your sink will draw when measuring ripple! 35mA for the calvin buffer? Try 500Ohms/min. 1W.
Forget my last post! I've just seen that you connected a load and Frans also suggested the same 
I should just stop working that much...
I should just stop working that much...
Frans, I do not have the time to go on evaluating my PSU, since I am very (too) busy with a TO3/DX - SYMASYM edition, offered to German DIYers currently.
Will you please go on?
You will have the PCBs in a couple of days (have them already?).
Best regards - Rudi_Ratlos
Will you please go on?
You will have the PCBs in a couple of days (have them already?).
Best regards - Rudi_Ratlos
Buffer PSU
Hi Rudi
Boards just arrived in Ireland they are brilliant
Thank a lot😀
Take care
Werner
Hi Rudi
Boards just arrived in Ireland they are brilliant
Thank a lot😀
Take care
Werner
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I will try to find some time for testing (but I was not planning on building the supply immediately, more like saving them for a later day).
Werner: give Frans some time, please! I am sure that he will evaluate my PCB very soon.
I am very unhappy that I cannot do this myself, but my workbench is crowded with plenty of TO3 - transistors (MJ21195G/MJ21196G) currently that need some matching due to a very special offer
of a "TO3/XD - SYMASYM" - version that I have offered to my German DIY-friends.
Best regards - Rudi_Ratlos
I am very unhappy that I cannot do this myself, but my workbench is crowded with plenty of TO3 - transistors (MJ21195G/MJ21196G) currently that need some matching due to a very special offer
of a "TO3/XD - SYMASYM" - version that I have offered to my German DIY-friends.
Best regards - Rudi_Ratlos
I m too late for a party with calvin buffer, Rudi. So no joy for me. Have to wait for another gb.
Calvin buffer as HP driver.
Hi Calvin,
what do you mean as "beefed up"?
I've got a couple remaning pcbs from Paradise phono pre and I'd like to try your buffer as HP driver.
As buffer in the phono pre it's Manifico!
Frank
Hi Calvin,
what do you mean as "beefed up"?
I've got a couple remaning pcbs from Paradise phono pre and I'd like to try your buffer as HP driver.
As buffer in the phono pre it's Manifico!
Frank
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