@russc I originally used LM2596 ( ready made board ) it died on 2 amps at 20v consumption. Another board i changed the inductor with a toroid type from a PC PSU ( change windings myself for 47 uH if I remember correctly , as the original inductor, measured it's inductance with an LCR meter .) worked fine , again it died on high power consumption.
Look at the L200 IC. It’s a little more complicated than LM317, but it’s got adjustable current limit and it’s easy to add an external transistor.
PS, I also need to build myself a lab power design, if you want I will throw something together tomorrow, im ordering boards anyway, and il be happy to send you a board at cost.
Cheers, V4lve
You can use a buck regulator to supply 2-3V more than the output voltage of a linear regulator. This is called a switching-pre regulator. I have prototyped this in the past, it works very well.
Mains switching PSU is really hard I can tell you from experience. Look at “pulse transformers” made by feryster at TME.EU if you need a flyback transformer allready wound. Winding your own is very complicated.
Look at what components like transformer and heatsink you may all ready have and then determine what you are going to build. Parts cost money, and a Chinese 30V 2A power supply that works is about €60-70. The only way for DIY to make financial sense is if you have or can get cheap: enclosure, Transformer, heatsink.
Electronics for a basic power supply will run anywhere from €10-30. Depending on if you want good quality potentiometers for the current and voltage control.
A heatsink for a 30V 2A supply will need to be able to dissipate approx 75W worst case. This is 2.5-3Kg of aluminium and costs €20-30 new.
A transformer for such a supply needs to be 25V 3.5A minimum. Another 20-30
Tell us what you have, and i we will try to steer you into a direction. If you are a student: I will gladly send you some parts for a symbolic sum.
Cheers,
V4lve
Mains switching PSU is really hard I can tell you from experience. Look at “pulse transformers” made by feryster at TME.EU if you need a flyback transformer allready wound. Winding your own is very complicated.
Look at what components like transformer and heatsink you may all ready have and then determine what you are going to build. Parts cost money, and a Chinese 30V 2A power supply that works is about €60-70. The only way for DIY to make financial sense is if you have or can get cheap: enclosure, Transformer, heatsink.
Electronics for a basic power supply will run anywhere from €10-30. Depending on if you want good quality potentiometers for the current and voltage control.
A heatsink for a 30V 2A supply will need to be able to dissipate approx 75W worst case. This is 2.5-3Kg of aluminium and costs €20-30 new.
A transformer for such a supply needs to be 25V 3.5A minimum. Another 20-30
Tell us what you have, and i we will try to steer you into a direction. If you are a student: I will gladly send you some parts for a symbolic sum.
Cheers,
V4lve
Here is the power supply schematic for the Delta E030-1. Here its known as the Mercedes of power supplies, very low noise, conservatively designed, reliable.
It uses an extra transformer winding to produce +10V and -5.6V relative to the + output. With this floating 10V reference the opamp sees the entire error voltage and as a result this is one of the best linear supplies I know of.
Cheers,
V4lve
It uses an extra transformer winding to produce +10V and -5.6V relative to the + output. With this floating 10V reference the opamp sees the entire error voltage and as a result this is one of the best linear supplies I know of.
Cheers,
V4lve
@v4lve lover Thank you for your suggestions and time to respond. I already have a few transformers, heatsinks,
I have the case from an old Voltcraft powersupply ( it was 13.8v 10A for car batteries or audio testing idk exactly ) I dont have it's transformer anymore, it was a beefy overbuild in my opinion transformer , 17 - 0 - 17 v ac rated 8 amps made an audio amp with it for a friend., anyway.
I do have one 37v DC I cut a few turns to make it that voltage, I think around 3 amps , and also one that has two 13 - 0 - 13 2.2A , if I could cut it open but its sealed with varnish, to rewind it in parallel for 13 - 0 - 13 4.4 A .
I also have a few LM723 , I have a few TL494, I have only one LM317 on hand, lots of small transistors ( BC546, 2n, 2sa, 2sc , etc ) , BD's , TIP's,
These old " cases" are strong iron, I did diy the cut for that V/A Meter, I might sand/ repaint the front. Maybe print on Photopaper , with " proper writings" for , Voltage adj, Current, etc . and stick it to the front and maybe cover it with a few coats of varnish
I forgot I also have a toroid , 200VA 26.5 - 0 - 26.5v ac 3a But I think its a bit to much for a test bench psu.
Anyway, here are some pics.
PS: Sorry for the mess ,
I have the case from an old Voltcraft powersupply ( it was 13.8v 10A for car batteries or audio testing idk exactly ) I dont have it's transformer anymore, it was a beefy overbuild in my opinion transformer , 17 - 0 - 17 v ac rated 8 amps made an audio amp with it for a friend., anyway.
I do have one 37v DC I cut a few turns to make it that voltage, I think around 3 amps , and also one that has two 13 - 0 - 13 2.2A , if I could cut it open but its sealed with varnish, to rewind it in parallel for 13 - 0 - 13 4.4 A .
I also have a few LM723 , I have a few TL494, I have only one LM317 on hand, lots of small transistors ( BC546, 2n, 2sa, 2sc , etc ) , BD's , TIP's,
These old " cases" are strong iron, I did diy the cut for that V/A Meter, I might sand/ repaint the front. Maybe print on Photopaper , with " proper writings" for , Voltage adj, Current, etc . and stick it to the front and maybe cover it with a few coats of varnish
I forgot I also have a toroid , 200VA 26.5 - 0 - 26.5v ac 3a But I think its a bit to much for a test bench psu.
Anyway, here are some pics.
PS: Sorry for the mess ,
Attachments
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Okay, you got some of the major parts
I am designing a PCB for my personal use, when its done i will post pictures of the design here.
Cheers,
V4LVE
I am designing a PCB for my personal use, when its done i will post pictures of the design here.
Cheers,
V4LVE