I'll guess you have pretty many opamps to choose from and NE5534 is not so bad. You should look for speed around 10-20 V/µs. If you want to choose faster opamps you may check the "super regulator" which has a class driver for the pass transistor.
What are you going to use the regulator for?
What are you going to use the regulator for?
I want only make test in phono preamp, line preamp and my analog circuit cd player because i use 78XX. As i wrote i have 32V. unreg. for PS phono and line preamp but i have 24V. reg for my 2 circuits. My PCB for this PS circuit is already design. I think used the AD817/DIP8. Can i use it this opamp?thank you!!
I think AD817 is a bit too fast but you can always test. In a super regulator it will work very nicely but then the pcb layout is very important.
maxpou said:
If you supply the opamp from the regulated output voltage rather than the unregulated input voltage, the improvement is more than you can do with any opamp swap - and is basically free.
You really should read the super reg threads.
Jan Didden
janneman said:
It's no improvement at all IMHO.
All those super-duper high-speed opamps is asking for trouble.
:bs:
The thing is that only some opamps will start if you do that unless you add some "trick", one of them can be found in the mentioned threads.janneman said:
In that schematic, the LM317 is set up to force the pass transistor to work at a fixed Vce of 1.25*(1000+825)/1000=2.28V. You can imagine it as an "active cascode". Knowing bipolar transistor behaviour at low Vce levels, I don't think that such a low Vce can provide any advantage, 5V would seem more reasonable.
No doubt that it can work that way, but the lower the Vce, the lower the current level and the frequency above which which hFE starts to roll-off.
Hi Peranders
is there much better result in the way than you connect the LM317 versus Borbely and what that changes? thank you!!!
is there much better result in the way than you connect the LM317 versus Borbely and what that changes? thank you!!!
I don't know if it's much better but it's rather practical and you don't have to trim the LM317.
hi, i send you the schematic and pcb with the modification for supply of IC1. please i would to know if it's correct or i can have problem.
IC1:AD817
D1,D2: BY255
C1,C2,C7,C11: WIMA MKP10 .01
C3,C4,C5,C6: NICHICON FW 4700UF
Q1: D44H11
C8,C9: 47UF ELNA CERAFINE
C10: 100UF ELNA CERAFINE
D3,D4: 1N4148
D5: LM329
I TRY LM317 AS JUNG LATER
IC1:AD817
D1,D2: BY255
C1,C2,C7,C11: WIMA MKP10 .01
C3,C4,C5,C6: NICHICON FW 4700UF
Q1: D44H11
C8,C9: 47UF ELNA CERAFINE
C10: 100UF ELNA CERAFINE
D3,D4: 1N4148
D5: LM329
I TRY LM317 AS JUNG LATER
Attachments
I'm afraid your design probably won't work. Have you thought about the startup? At zero volts, how will the opamp work?
Elso Kwak said:
It's no improvement at all IMHO.
All those super-duper high-speed opamps is asking for trouble.
:bs:
That fateful phrase from Audio Amateur "It oscillates, now what" --
- Status
- Not open for further replies.