B grade is high current jFET, C grade is very hugh current jFET.
If A grade is specified, then you needto be able to redesign the circuit to suit the modification you are proposing.
If A grade is specified, then you needto be able to redesign the circuit to suit the modification you are proposing.
Friends, good morning,
I built this PSU, and I have a problem, turning the trimmer (from 4k7), both positive and negative, the voltage increase is adjusted to 11volt, then suddenly switches to 20V just tap to get to 38V full scale. I used the bf245a. and 'too sensitive !!? I have to change trimmer?
Friends, good morning,
I built this PSU, and I have a problem, turning the trimmer (from 4k7), both positive and negative, the voltage increase is adjusted to 11volt, then suddenly switches to 20V just tap to get to 38V full scale. I used the bf245a. and 'too sensitive !!? I have to change trimmer?
... But, if I replace instead of 4k7 trimmer a calculated resistor for voltage +/- 24V .. ??
This looks like a great next step after a 317/337 supply. Higher current than the super-shunt regs and easy adjustability 😀.
However, I can't find any stock of BF245A in any of the shops here, but I do have BF245B and C on hand. The original schematic, in post #1, simply specifies "BF245". I've reattached it here for simplicity.
Does the suffix not matter in this version? Or do I need to keep looking for the A variant?
Many thanks!
However, I can't find any stock of BF245A in any of the shops here, but I do have BF245B and C on hand. The original schematic, in post #1, simply specifies "BF245". I've reattached it here for simplicity.
Does the suffix not matter in this version? Or do I need to keep looking for the A variant?
Many thanks!
Attachments
measure to find the lowest Idss of the B grade.
Then add a source resistor to trim down the Id to what the circuit needs.
Then add a source resistor to trim down the Id to what the circuit needs.
Hello apexaudio
greetings i want to build your Aclass power supply for +/- 15 volts
will supply work with 18 0 18 AC 1 ampere transformer
warm regards
Andrew
greetings i want to build your Aclass power supply for +/- 15 volts
will supply work with 18 0 18 AC 1 ampere transformer
warm regards
Andrew
Hello apex audio
Can this psu deliver 1ampere output current.
Can i remove 22r resistor to increse output current and In place of 22r resistor add jumper.
My traffo is 18-0-18 2 ampere
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Can the shunt supply in post #46 be used as the front end supply for a class A amp, increasing the voltage to between 24 and 30 volts? Should the output stage supply also be ramped up slowly to match the settling time of the front end supply? Thanks in advance.
Can the shunt supply in post #46 be used as the front end supply for a class A amp, increasing the voltage to between 24 and 30 volts? Should the output stage supply also be ramped up slowly to match the settling time of the front end supply? Thanks in advance.
Sir, I have BF245B and I made the circuit wit 5K pot. I am unable to adjust the voltage.
What are the changes to be made for BF245B and for using with a 12-0-12 transformer?