Hello all. After very long I am posting & this time I want help for making a dual rail high current variable power supply for testing projects. I already have a dual supply with Lm317 and Lm337 supply but the current is insufficient for testing projects upto 3 Ampere so I want to know how can I increase the current upto 3 Ampere or more upto 5 Ampere in future. I also made a variable power supply using switch mode buck converter with XL4016 but it's only single output that's positive and ground but I want positive ground and negative output which is not available readily and I can't buy those expensive bench supplies like from Siglent so please advise me
You can use a transistor as an emitter follower to increase the output of the the LM3x7 like this:
For the negative powerrail you have to use PNP transistors instead oF NPN.
Example schematic comes from
this website.
For the negative powerrail you have to use PNP transistors instead oF NPN.
Example schematic comes from
this website.
There are indeed much better ways but as he asked about increasing the output this is the most easy option. If he wants to stay with the LM3x7 regulators he could use a transformer with multiple taps and use a relay to switch between those. Plenty of example schematics can be found.
On the other hand, if you have to buy a transformer and heatsinks a second hand linear lab power supply might be cheaper.
On the other hand, if you have to buy a transformer and heatsinks a second hand linear lab power supply might be cheaper.
Build a simple linear CLC or CRC power supply which can supply the maximum voltage and current that you need and adjust the voltage with a variable autoformer (Variac).
A Variac is a handy device to have when testing amplifiers, as well.
Edit: Just to be clear, when I said "Build a linear ... power supply", I meant one complete with a power transformer, since an autoformer does not provide isolation from the AC mains,
A Variac is a handy device to have when testing amplifiers, as well.
Edit: Just to be clear, when I said "Build a linear ... power supply", I meant one complete with a power transformer, since an autoformer does not provide isolation from the AC mains,
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Recieved some parts for psu project.
The teensy 4.1 (i now get its name, its very small)
And the nextion 7 inch touch display.
Stil missing dac8830 for Analog control.
I started layout on prototype pcb for teensy, terminals for easy connection, trimpots as Voltage dividers, converting psu 0-5 volt into 3.3 volt, which teensy sadly only accept. Maybe i should go with resistors instead.
Next up soldering, and the try to produce a nice gui interface in nextions editor.
The teensy 4.1 (i now get its name, its very small)
And the nextion 7 inch touch display.
Stil missing dac8830 for Analog control.
I started layout on prototype pcb for teensy, terminals for easy connection, trimpots as Voltage dividers, converting psu 0-5 volt into 3.3 volt, which teensy sadly only accept. Maybe i should go with resistors instead.
Next up soldering, and the try to produce a nice gui interface in nextions editor.
So where at it again, me and my buddy, calibrating dsc boards.
I thought it would be easy , but guess again, the chips are not totally linear, so have done many measuring points and calibrated for non linearities, can hit 3.0000 vollt om both outputs , same with other values to, very nice.
I thought it would be easy , but guess again, the chips are not totally linear, so have done many measuring points and calibrated for non linearities, can hit 3.0000 vollt om both outputs , same with other values to, very nice.
I would put the reference of the LM317 to the output. Check stability but I don't see a quick reason why it shouldn't work.
A linear bipolar supply would look something like this:
But ironically if you need help designing such a supply, then you probably need a professional supply that has all the protection, metering etc that comes with a professional product. The idea of using a variac driving a simple supply is not a bad idea. There are switching variable regulator modules available that could be used with off the shelf fixed supplies, could be a good way to go. In this simulation, the negative supply tracks the positive supply which could be improved, but perhaps not worth the trouble.
https://www.amazon.com/Adjustable-R...sprefix=variable+voltage,aps,243&sr=8-29&th=1
But ironically if you need help designing such a supply, then you probably need a professional supply that has all the protection, metering etc that comes with a professional product. The idea of using a variac driving a simple supply is not a bad idea. There are switching variable regulator modules available that could be used with off the shelf fixed supplies, could be a good way to go. In this simulation, the negative supply tracks the positive supply which could be improved, but perhaps not worth the trouble.
https://www.amazon.com/Adjustable-R...sprefix=variable+voltage,aps,243&sr=8-29&th=1