Build a darn variable volts and current benchtop power supply

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paulrockwell

Joined May 17, 2021
2
I need a triat dot to dot how to build a benchtop power supply with detailed info I have hard time at figuring all ic,s transistors like i built the crappy hilego power supply 3 time all of them burned I have hole garage full of parts from amazon like what would be va better ic for the tl081??? but that power supplys not what i want i want one that easy to make not going to brake or burn that puts out from a 120ac wall to start with one please help me before i pull my hair out that puts out 60 to 100vdc and upto 10 to 20 amps current andcan be adjusted for volts and amps i have the fallowing,
IC kits ne555,5532/lm358,386,393,324,339 the kit and hole bag bor resistors,now beltrolitic caps i have 5,35v 3300uf,1000uf couple 200v 220uf, around same in 25vdc and 16vdc,all uf valusebunch old atx power supplysand 1zk-sjva-4x-v2 adustable converter,1boost converter 600w 10 to 60v and go 12 to 80v,1witch i would use is a comicox dc-dc 8-32 to 45-390 converter step up on 2 and buck boost on 1give me a dot to dot please. thank very very very much paul
 

Papabravo

Joined Feb 24, 2006
16,105
I don't know what a "triat" is, and I have no idea what "dot to dot" means. Can you help with a better explanation?
I have a feeling that you are going about this project all wrong. Nobody who knows anything about what they are doing starts with a pile of parts and says: "I'm going to make a 2000 watt (100 volts x 20 amps) power supply out of this collection of parts". That approach leads to the situation you are in: you have a pile of parts and nothing to show for it.

There are several steps to such a project that I do not feel you have taken:
  1. If you are having no luck at designing and building, you should consider purchasing something.
  2. You need a single, straight forward, set of requirements. Not a hodgepodge of run on sentences.
  3. You need a design
  4. You need to verify the design, with other eyeballs looking at it
  5. Then, and only then do you acquire the parts.
  6. Build and test the design in stages to build confidence that you understand what you are doing and what your testing shows.
 
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sparky 1

Joined Nov 3, 2018
539
The solderless protoboard uses a Hiletgo power adapter and you want to use a grab bag of ICs but they draw too much current ?
Did you check the schematic to set the jumpers. Is there a short across the power rails. Is the Vregulator getting power.
If it is burned out it still ok as a plug on board take out the old Vreg

http://www.hiletgo.com/ProductDetail/1949383.html
 
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BobaMosfet

Joined Jul 1, 2009
1,768
I need a triat dot to dot how to build a benchtop power supply with detailed info I have hard time at figuring all ic,s transistors like i built the crappy hilego power supply 3 time all of them burned I have hole garage full of parts from amazon like what would be va better ic for the tl081??? but that power supplys not what i want i want one that easy to make not going to brake or burn that puts out from a 120ac wall to start with one please help me before i pull my hair out that puts out 60 to 100vdc and upto 10 to 20 amps current andcan be adjusted for volts and amps i have the fallowing,
IC kits ne555,5532/lm358,386,393,324,339 the kit and hole bag bor resistors,now beltrolitic caps i have 5,35v 3300uf,1000uf couple 200v 220uf, around same in 25vdc and 16vdc,all uf valusebunch old atx power supplysand 1zk-sjva-4x-v2 adustable converter,1boost converter 600w 10 to 60v and go 12 to 80v,1witch i would use is a comicox dc-dc 8-32 to 45-390 converter step up on 2 and buck boost on 1give me a dot to dot please. thank very very very much paul
:: gobsmacked :: Is there anyone reading this that doesn't see the inherent warnings????
 

atferrari

Joined Jan 6, 2004
4,321
I need a triat dot to dot how to build a benchtop power supply with detailed info I have hard time at figuring all ic,s transistors like i built the crappy hilego power supply 3 time all of them burned I have hole garage full of parts from amazon like what would be va better ic for the tl081??? but that power supplys not what i want i want one that easy to make not going to brake or burn that puts out from a 120ac wall to start with one please help me before i pull my hair out that puts out 60 to 100vdc and upto 10 to 20 amps current andcan be adjusted for volts and amps i have the fallowing,
IC kits ne555,5532/lm358,386,393,324,339 the kit and hole bag bor resistors,now beltrolitic caps i have 5,35v 3300uf,1000uf couple 200v 220uf, around same in 25vdc and 16vdc,all uf valusebunch old atx power supplysand 1zk-sjva-4x-v2 adustable converter,1boost converter 600w 10 to 60v and go 12 to 80v,1witch i would use is a comicox dc-dc 8-32 to 45-390 converter step up on 2 and buck boost on 1give me a dot to dot please. thank very very very much paul
As a non native I find your post, a mass of text hard to understand.
I always believe that the way you write is the way you speak. Hard to follow.
Capitals, paragraphs and punctuation form part of natural efforts to convey what you want actually say.
 

Dodgy Geezer

Joined Nov 30, 2009
169
I find the words in this request a bit easier to understand. But then, I did Middle English as part of my degree, a language where there is no authoritative spelling and where the phonetics are a better clue to the meaning.

He wants someone to provide him with precise details for building a reasonably high capability power supply 'that will not brake or burn', unlike the last three Hilego ones that he built. Since Hilego mainly seem to offer 5v and 3.3v regulated power supplies, I wonder why he wants something which will output 100v at 20A max? Perhaps this gives a hint as to what happened to his last three...?
 

MrAl

Joined Jun 17, 2014
8,239
I need a triat dot to dot how to build a benchtop power supply with detailed info I have hard time at figuring all ic,s transistors like i built the crappy hilego power supply 3 time all of them burned I have hole garage full of parts from amazon like what would be va better ic for the tl081??? but that power supplys not what i want i want one that easy to make not going to brake or burn that puts out from a 120ac wall to start with one please help me before i pull my hair out that puts out 60 to 100vdc and upto 10 to 20 amps current andcan be adjusted for volts and amps i have the fallowing,
IC kits ne555,5532/lm358,386,393,324,339 the kit and hole bag bor resistors,now beltrolitic caps i have 5,35v 3300uf,1000uf couple 200v 220uf, around same in 25vdc and 16vdc,all uf valusebunch old atx power supplysand 1zk-sjva-4x-v2 adustable converter,1boost converter 600w 10 to 60v and go 12 to 80v,1witch i would use is a comicox dc-dc 8-32 to 45-390 converter step up on 2 and buck boost on 1give me a dot to dot please. thank very very very much paul
Hi,

There is quite a bit of thought put into these kinds of power supplies. You would think power supplies would be one of the simplest things to design but they can be very complicated because there are a lot of design goals that have to be met to get something decent out of it.
Cost of course is very important when the idea is to sell the end product commercially and there are some regulations that come into play too. If you are making a one off unit just for your own purposes then these things are not as important usually.

The basic higher powered power supply starts with a tracking switching regulator front end. That is a regulator that has decent efficiency so as to not waste too much energy and at the same time keep the unit cooler and also self adjusts to track the output of the back end to some degree. The back end would be a linear regulator that can provide a clean output free from most switching transients. The unit would also have a course and fine voltage and current limit adjustments. You may also want to have some built in meters to be able to monitor the output without having to connect meters to the unit when it is being used.

If you look around the web you can find entire schematics although the parts identifications may be a little difficult to figure out. You can improvise there, but i have a feeling you are not going to like the complexity found in any of these things. That may lead you to just want to buy a unit if you can find one that meets your needs. If you cant find one then you have to build your own.

As others have pointed out 100 volts at 20 amps is 2000 watts. That is nearly the maximum power available in an ordinary household 120vac 60Hz outlet. That may mean you need an entire circuit dedicated to that power supply alone. The question then comes up as to what you want to use this for. That's a lot of power especially for a DC supply. Maybe you want to test circuit breakers or something, but if you care to mention what you intend to use this for maybe there is a simpler solution.

An important point to remember also is safety. Power supply circuit elements can literally blow up like ash cans or even worse. The stuff i have seen over the years would make you afraid to work around a new design without some good face and eye protection as well as a blast shield. When circuit elements explode they can spew out molten metal in all directions. I have seen the metal cases of transistors that have exploded look like someone used one as a welding rod. Entire metal tops melted and blown right off. Little beads of copper left behind in place of the metal that once was the case of the power transistor.
Power devices work with lots of energy sometimes and energy can be released rapidly just like in any kind of explosion. You dont want to get hit by a wad of hot molten copper.

Of course there is the electrical potential present in any line operated equipment making shock hazard a reality. This also brings up the question of galvanic isolation input to output. Power supplies like this should have an output that is electrically isolated from the input so the user does not risk electric shock from the output to ground.
 
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anniel747

Joined Oct 18, 2020
1,034
I need a triat dot to dot how to build a benchtop power supply with detailed info I have hard time at figuring all ic,s transistors like i built the crappy hilego power supply 3 time all of them burned I have hole garage full of parts from amazon like what would be va better ic for the tl081??? but that power supplys not what i want i want one that easy to make not going to brake or burn that puts out from a 120ac wall to start with one please help me before i pull my hair out that puts out 60 to 100vdc and upto 10 to 20 amps current andcan be adjusted for volts and amps i have the fallowing,
IC kits ne555,5532/lm358,386,393,324,339 the kit and hole bag bor resistors,now beltrolitic caps i have 5,35v 3300uf,1000uf couple 200v 220uf, around same in 25vdc and 16vdc,all uf valusebunch old atx power supplysand 1zk-sjva-4x-v2 adustable converter,1boost converter 600w 10 to 60v and go 12 to 80v,1witch i would use is a comicox dc-dc 8-32 to 45-390 converter step up on 2 and buck boost on 1give me a dot to dot please. thank very very very much paul
Get a 20 Amp (or more) Variac followed by a bridge and capacitor(s), done deal.
 

MrAl

Joined Jun 17, 2014
8,239
Looks like a Darwin Award.
Not sure what you mean but these kinds of supplies tend to be very useful.
I have a couple 300 watter's and a small 30 watter too.
Another benefit of using a switcher front end is you can make it work at 120vac or 230vac with no change to the input circuit, or maybe a switch to switch between the two with nothing else added.
 

anniel747

Joined Oct 18, 2020
1,034
Not sure what you mean but these kinds of supplies tend to be very useful.
I have a couple 300 watter's and a small 30 watter too.
Another benefit of using a switcher front end is you can make it work at 120vac or 230vac with no change to the input circuit, or maybe a switch to switch between the two with nothing else added.
Do you really think the TS can manage to build this? Unless he's a troll.
 

MrAl

Joined Jun 17, 2014
8,239
Do you really think the TS can manage to build this? Unless he's a troll.
Well really i do not attempt to judge i just put the facts out there. Other people will eventually read this thread also.

Feel free to put your own design ideas here too.
 

anniel747

Joined Oct 18, 2020
1,034
Well really i do not attempt to judge i just put the facts out there. Other people will eventually read this thread also.

Feel free to put your own design ideas here too.
TS has not been seen since his second post stating he has figured it out and I already given the simplest way to easily achieve what he wanted.
 

MrAl

Joined Jun 17, 2014
8,239
TS has not been seen since his second post stating he has figured it out and I already given the simplest way to easily achieve what he wanted.
Oh yes i saw your post #16. I got a variac too for that same reason but i also needed AC variations for other things. The problem though is that it is not regulated. Around here we have variations in the AC line voltage that can sometimes dip as low as 80 volts although 100 is more typical, but for a 120vac nominal line voltage that is about a 20 percent variation. Regulated power supplies do much much better than that with not only line regulation but load regulation as well. Not sure if you ever tracked the voltage regulation of a bridge rectifier and filter cap with load changes even when the input line is constant, but it's not very good either.
Cant beat a variac and rectifier for simplicity but if you need decent regulation you have to do more.

Also, once a discussion starts we often talk about it a bit more even though the 'thread starter' doesnt return right away, and sometimes they do come back days or weeks later with more questions and other ideas.

One of my AC tests with the variac was quite interesting. It was to test the cooking power of a cheap microwave oven with reduced input line voltage. I wanted to see how much microwave cooking power could be varied in this way and compare it to inverter type microwave ovens that cook with continuous reduced power rather than pulsed peak power. Turns out it works although adjusting can be a little tricky sometimes and again that was because the output of the variac is not regulated.
 

anniel747

Joined Oct 18, 2020
1,034
Oh yes i saw your post #16. I got a variac too for that same reason but i also needed AC variations for other things. The problem though is that it is not regulated. Around here we have variations in the AC line voltage that can sometimes dip as low as 80 volts although 100 is more typical, but for a 120vac nominal line voltage that is about a 20 percent variation. Regulated power supplies do much much better than that with not only line regulation but load regulation as well. Not sure if you ever tracked the voltage regulation of a bridge rectifier and filter cap with load changes even when the input line is constant, but it's not very good either.
Cant beat a variac and rectifier for simplicity but if you need decent regulation you have to do more.

Also, once a discussion starts we often talk about it a bit more even though the 'thread starter' doesnt return right away, and sometimes they do come back days or weeks later with more questions and other ideas.

One of my AC tests with the variac was quite interesting. It was to test the cooking power of a cheap microwave oven with reduced input line voltage. I wanted to see how much microwave cooking power could be varied in this way and compare it to inverter type microwave ovens that cook with continuous reduced power rather than pulsed peak power. Turns out it works although adjusting can be a little tricky sometimes and again that was because the output of the variac is not regulated.
TS did not mention he needed any sort of regulation, he only wanted lots of power.
 

MrAl

Joined Jun 17, 2014
8,239
TS did not mention he needed any sort of regulation, he only wanted lots of power.
You serious? :)
When is the last time you saw a benchtop power supply that didnt have good regulation.
Usually they have not only voltage regulation but also current limit regulation, and even fine and coarse adjustments for both.
Re-read the first post in this thread and note the following in particular:
"benchtop power supply"
"and can be adjusted for volts and amps"
I dont know maybe i am reading too much into this but i cant see it being any other way.
Dont get me wrong though i do like the variac idea too for some things.

I need a triat dot to dot how to build a benchtop power supply with detailed info I have hard time at figuring all ic,s transistors like i built the crappy hilego power supply 3 time all of them burned I have hole garage full of parts from amazon like what would be va better ic for the tl081??? but that power supplys not what i want i want one that easy to make not going to brake or burn that puts out from a 120ac wall to start with one please help me before i pull my hair out that puts out 60 to 100vdc and upto 10 to 20 amps current andcan be adjusted for volts and amps i have the fallowing,
IC kits ne555,5532/lm358,386,393,324,339 the kit and hole bag bor resistors,now beltrolitic caps i have 5,35v 3300uf,1000uf couple 200v 220uf, around same in 25vdc and 16vdc,all uf valusebunch old atx power supplysand 1zk-sjva-4x-v2 adustable converter,1boost converter 600w 10 to 60v and go 12 to 80v,1witch i would use is a comicox dc-dc 8-32 to 45-390 converter step up on 2 and buck boost on 1give me a dot to dot please. thank very very very much paul
 

anniel747

Joined Oct 18, 2020
1,034
You serious? :)
When is the last time you saw a benchtop power supply that didnt have good regulation.
Usually they have not only voltage regulation but also current limit regulation, and even fine and coarse adjustments for both.
Re-read the first post in this thread and note the following in particular:
"benchtop power supply"
"and can be adjusted for volts and amps"
I dont know maybe i am reading too much into this but i cant see it being any other way.
Dont get me wrong though i do like the variac idea too for some things.
I have a few on the bench and some get daily usage.
 
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