My batch would all be covered by one resistor value. Can't remember what though!
Sorry Nic have been away...(Goodwood Festival of Speed)😃
680r !
https://www.diyaudio.com/community/...-ultrabib-shunt-regulator.322411/post-7012972
680r !
https://www.diyaudio.com/community/...-ultrabib-shunt-regulator.322411/post-7012972
Howdy. I am breadboarding a raw psu for my next gen bufferpre-channelselect-stepped attenuator-active xover-differential balanced out thingie. Opamp-based taking +/- 15 v regulated ca 180-200 mA per rail is my guess. I havent built it yet. Starting here for layout decisions, comp choices etc.
This is a for the usecase slightly overkill 2x18 v 80 VA to a quasimodo tuned crc network to stealth II soft recovery bridges to 3900uF-10R-4700-uF loading dummies to 300 mA with virtually no ripple left. They will feed a pair of 1.3 set to approximately that load I was thinking.
Workable?
This is a for the usecase slightly overkill 2x18 v 80 VA to a quasimodo tuned crc network to stealth II soft recovery bridges to 3900uF-10R-4700-uF loading dummies to 300 mA with virtually no ripple left. They will feed a pair of 1.3 set to approximately that load I was thinking.
Workable?
Attachments
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Got some scope pix as well. Probes on 10x, adjusted for in scope readings.
First and second C
A zoom in on the falling edge on the first C. Looks good.
Close up on second c rms ripple. Ca 5 mV and not so thick line.
Decent for a filter on a plank and probes with long ground clips.
First and second C
A zoom in on the falling edge on the first C. Looks good.
Close up on second c rms ripple. Ca 5 mV and not so thick line.
Decent for a filter on a plank and probes with long ground clips.
Before I blob the 3-leggers down, most my J1-J3 PF5102 from TB was in the 8 region IDSS (with DCA Pro) and one in the 5 region. It doesnt matter at all where i put them does it?
No, the donut gives a little more juice than needed so I take the voltage down some 3 volts with a C-R10 before the boards. Hence also the rectifying and the Quasimodo snubbing goes on another little pre-board. Also Rf. I ment room for that on the sink. After that it goes straight into C1/R1
You know about optionally using 4k7 NTC across R5 if you must counter BJT Vbe Tc drift in the Vref, yes?
I did not, I have not had the time to read the entire thread, just the manual. Please update me!
I got some scope readings after they have gone warm for an hour or so. Short gnd over output terminals. Ca 210 mA load and some 290 as current setting.
Positive rail. Scope measure said ca 169 uV RMS @ some 3-400 Hz
Negaitive rail about 340 uV RMS.
Edit, the frequency was lower. I think it is catching up from the 230 vac power in line, they are just a centimeter apart. I will rearrange that later.
I got some scope readings after they have gone warm for an hour or so. Short gnd over output terminals. Ca 210 mA load and some 290 as current setting.
Positive rail. Scope measure said ca 169 uV RMS @ some 3-400 Hz
Negaitive rail about 340 uV RMS.
Edit, the frequency was lower. I think it is catching up from the 230 vac power in line, they are just a centimeter apart. I will rearrange that later.
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Thanks, good to know. My drift is about -200 mV from start now. My load will be opamps gladly taking up to +/- 18 vdc. And since the drift seems to affect both positive and negative in the same manner I dont think it affects this application.
I will rearrange cabling and go down to 5k trim though. 20 k was like the gas pedal on a top fuel nitro dragster. I just had to think ”turn superlittle” and it went up 50 mV 🙂
I will rearrange cabling and go down to 5k trim though. 20 k was like the gas pedal on a top fuel nitro dragster. I just had to think ”turn superlittle” and it went up 50 mV 🙂