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PeeCeeBee PSU GB

Hi, it looks like you didn't include the component for the transformer snubber !

Hi Patriz.

Since there are a lot of simulations and speculations and "expert opinions" on this matter, I felt confused and decided to run my own experiments and here are the results and my thoughts.

Here is switching curve traced in AC mode right at the output leg of the diode D1 and transformer center tap. The transient looks exacly as expected and there is also a tiny notch visible on the decay curve, sufficient to trigger ringing I suppose? But there is no ringing. Scope bandwidth 100MHz, bandwidth limiting and digital filters disabled. Interestingly, the curve is absolutely same with or without snubbers accross the diodes and/or secondary winding.

hVSEJaQkLW42WmdXFUtqjln1quJmshA2iqemycMGmtnJrO49i8XcHnaE5nzheWQ5atXdmWaxl5wjLPfVREy2rLzGDUUQ2HR0RDIBXtt-cWoHxFNfPD2v1o1HLZhUaICHhyE94kJcnwE=w1024

Indeed, in 50/60Hz rated linear PSUs the snubbers practically serve no purpose and can be safely omitted. Note that in the layout there are two 1nF ceramic capacitors between rectifier output and main capacitor bank. These are preferebly ceramics as ceramic capacitors have much better HF noise decoupling behavior (low HF impedance) than film types or electrolytics (silver-mica would probably be better yet but are expensive as hell). These capacitors ensure than any HF noise, if ever emerged at the rectifier outputs, are shunned to ground before reaching the main capacitors, which may have significant HF impedance at or above 100KHz.

I hope this explains it. If I missed something or there are better ways to evaluate the effects of subbers in linear supplies then do let me know.

Thanks
shaan
 
GB List:

Nisbeth - 4 PCBs
loafimus - 1 PCBs
fencki - 1 PCBs
yoaudio - 2 PCBs
asuslover - 1 PCBs
bvtrinh - 4 PCBs
NishantS - 1 PCBs
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB.
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
 
GB List:

Nisbeth - 4 PCBs
loafimus - 1 PCBs
fencki - 1 PCBs
yoaudio - 2 PCBs
asuslover - 1 PCBs
bvtrinh - 4 PCBs
NishantS - 1 PCBs
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB.
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
 
GB List:

Nisbeth - 4 PCBs
loafimus - 1 PCBs
fencki - 1 PCBs
yoaudio - 2 PCBs
asuslover - 1 PCBs
bvtrinh - 4 PCBs
NishantS - 1 PCBs
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB.
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
ecclesand - 2 PDBs

I'll take 2
 
Ok then. I´ll take 4
Piling up with pcbs here..... Not enough time..

Nisbeth - 4 PCBs
loafimus - 1 PCBs
fencki - 1 PCBs
yoaudio - 2 PCBs
asuslover - 1 PCBs
bvtrinh - 4 PCBs
NishantS - 1 PCBs
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB.
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
ecclesand - 2 PCBs
zebulo - 2 PCBs
bambadoo - 4 PCBs

-----------------------------
Total 96 PCBs
 
1 PCB for me

Nisbeth - 4 PCBs
loafimus - 1 PCBs
fencki - 1 PCBs
yoaudio - 2 PCBs
asuslover - 1 PCBs
bvtrinh - 4 PCBs
NishantS - 1 PCBs
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB.
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
ecclesand - 2 PCBs
zebulo - 2 PCBs
bambadoo - 4 PCBs
gopib - 1 PCB
-----------------------------
Total 97 PCBs
 
Nisbeth - 4 PCBs
loafimus - 1 PCB
fencki - 1 PCB
yoaudio - 2 PCBs
asuslover - 1 PCB
bvtrinh - 4 PCBs
NishantS - 1 PCB
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
ecclesand - 2 PCBs
zebulo - 2 PCBs
bambadoo - 4 PCBs
gopib - 1 PCB
steefdebruijn - 4 PCBs
 
Hi Shaan,
The PSU board is rated from +/-20V to +/-56V.
I have a 500VA toroidal transformer with secondarys @ 40VAC, giving a rectified rail voltage a smidge over 56VDC.
May I ask what particular components are critical for the rail voltage to go to +/-58VDC?
kind regards
stevet
 
Hi Shaan,
Looking at the circuit, the rectification part should not be a problem with slightly higher voltages. I see you have sized things up for a maximum of 10amps, and my transformer is 6amps-ish . I guess the area to look at for slightly higher voltage is the sensing side of the circuitry.
kind regards
stevet
 
Hi Shaan,
The PSU board is rated from +/-20V to +/-56V.
I have a 500VA toroidal transformer with secondarys @ 40VAC, giving a rectified rail voltage a smidge over 56VDC.
May I ask what particular components are critical for the rail voltage to go to +/-58VDC?
kind regards
stevet

Hi Shaan,
Looking at the circuit, the rectification part should not be a problem with slightly higher voltages. I see you have sized things up for a maximum of 10amps, and my transformer is 6amps-ish . I guess the area to look at for slightly higher voltage is the sensing side of the circuitry.
kind regards
stevet

Hi Stevet.

Other than a higher calculated value of R9,10,11,12 and 2Watt rating for them there is nothing that needs to be changed for 58V. I have tested it with maximum 56V so mentioned only that in first post.
 
Nisbeth - 4 PCBs
loafimus - 1 PCB
fencki - 1 PCB
yoaudio - 2 PCBs
asuslover - 1 PCB
bvtrinh - 4 PCBs
NishantS - 1 PCB
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
ecclesand - 2 PCBs
zebulo - 2 PCBs
bambadoo - 4 PCBs
gopib - 1 PCB
steefdebruijn - 4 PCBs
jls001 - 2 kits
 
2 more...

Nisbeth - 4 PCBs
loafimus - 1 PCB
fencki - 1 PCB
yoaudio - 2 PCBs
asuslover - 1 PCB
bvtrinh - 4 PCBs
NishantS - 1 PCB
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
ecclesand - 2 PCBs
zebulo - 2 PCBs
bambadoo - 4 PCBs
gopib - 1 PCB
steefdebruijn - 4 PCBs
jls001 - 2 kits
Dirttracker73 - 2 PCBs
 
Nisbeth - 4 PCBs
loafimus - 1 PCB
fencki - 1 PCB
yoaudio - 2 PCBs
asuslover - 1 PCB
bvtrinh - 4 PCBs
NishantS - 1 PCB
solviken - 2 PCBs
helfred - 4 PCBs
kokanee - 4 PCBs
Lutto - 4 PCBs
Gwrskien - 4 PCBs
craydive - 6 PCBs
CitizenKane - 4 PCBs
SigFire - 2 PCBs
tome - 4 PCBs
kpsthakur - 2 PCBs
waeah - 1 PCB
ckwong99 - 4 PCBs
spind - 4 PCBs
emynet - 4 PCBs
vvs07 - 4 PCBs
vasillis - 4 PCBs
nealj - 2 PCBs
leejh - 4 PCBs
gannaji - 1 PCB
muthumuthiah - 2 PCBs
reaper996 - 1 PCB
dcoff - 2 PCBs
pieter t - 3 PCBs
Malvin - 2 PCBs
ecclesand - 2 PCBs
zebulo - 2 PCBs
bambadoo - 4 PCBs
gopib - 1 PCB
steefdebruijn - 4 PCBs
jls001 - 2 kits
Dirttracker73 - 2 PCBs
mexakin - 2 PCBs

thank you
 
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