Salas SSLV1.3 UltraBiB shunt regulator

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Works with IRF610:):up:
 

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1) Is there a preference for either the ES BP or KZ series of capacitors in positions C1 and C3?

2) I am considering to using flat aluminum bar sock 1/4" thick 5" long X 1" wide attached to the bottom plate of my enclosure for heat sinking of R1, M1 and M2 as shown in the photo in post #1. R1=5.6 Ohms, CC=105mA, Maximum Load 5mA Output +/-15V. Will this provide sufficient heat sinking in my application?
 
diyAudio Chief Moderator
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1) Is there a preference for either the ES BP or KZ series of capacitors in positions C1 and C3?

2) I am considering to using flat aluminum bar sock 1/4" thick 5" long X 1" wide attached to the bottom plate of my enclosure for heat sinking of R1, M1 and M2 as shown in the photo in post #1. R1=5.6 Ohms, CC=105mA, Maximum Load 5mA Output +/-15V. Will this provide sufficient heat sinking in my application?

1) C2 KZ C3 BP is a nice combo. C1 is the big reservoir cap.

2) R1 doesn't need heat sinking. That aluminum bar size you mentioned will do for your settings when attached to the enclosure's bottom plate, remember to use thermal paste between it and the bottom plate.
 
diyAudio Chief Moderator
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By the way, what is it for? Those +/-15V 5mA sound like its an op-amp. Max 5mA load seems bit small though. Is that about the max idle current datasheet spec? Maybe use 4.7R R1 for extra mA towards signal swing headroom while staying above the 100mA spare current recommendation.

Or do that simply against any chance of unfortunate parts tolerances conspiring to hit on your CC target short. Few more CC mA will not create an appreciable difference to M1 & M2's dissipation at such rails level anyway.
 
Yes. It is an AD744 Op Amp. There are two. One per channel. I am using 4 shunt regulators. Two for each Op Amp. One +15v one -15v for each Op Amp.
The Max Quiescent current is 5mA. The Typical Short Circuit Output Current is 25mA.

Also on the board I will be powering I am replacing 4 78 type regulators with the shunt regulators. There is currently a 220uF KZ type capacitor across the output of the regulator and the +/- supply for the Op Amps. Is it appropriate to leave them in place or remove them and only use the output cap on the shunt regulators?
 
diyAudio Chief Moderator
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Thus 4.7R R1 is better to use given the 25mA short circuit capability of those op-amps. In case they will ever drive signal to some demanding load or longer interconnects.

Other than small value local capacitors next to the power pins of the op-amps, further big capacitors on the rails are usually superfluous (resulting to heavier sound) when the shunt regs will be in the same box connected to the op-amp board with rather short and thick enough output cables.
 
O.K. I will omit the 220uF caps and tie the outputs of the regs directly to the Op Amps +/- pins.

I have 4 Ohm resistors on hand. That would give me CC 150mA. Would that provide acceptable dissipation with my proposed heat sink strategy using the 1/4" aluminum bars attached to the bottom of the chassis?
 
diyAudio Chief Moderator
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Are there 10uF//0.1uF decoupling caps at the op-amp power pins already? Those are important. How long the reg output cables are going to be?

4R for 150mA CC alright it will take it but keep the waste and temperature bit more moderate if you can. Do you have any 47R 1/4W resistors to parallel across each 5.6R R1 either piggyback or under the board? That will make 5R total. A sweet value.
 
My supply lines will be longer than 5cm. I will use the 5R for CC of 120mA.

Is the phasing/leading side of the transformer secondaries important when feeding AC to the +/- UBiB boards? The Custom Magnetics R Core transformers that I have do not have the winding phase indicated on the transformers.