Nice job. Thanks for taking the time to show how you did that. For what it's worth, I cut out panels the same way. The only difference is I drill out the corners first, & then file out the fine details. I have lots of different tools at hand, but that seems to work pretty good for me.
Like anything else. Practice & persistence. People around me think that I am smart ( I fooled them) because I build electronic things like you. A few years ago I didn't even know how to open a laptop computer, let alone use it. Now I'm building a CNC machine. I tell them they could do it to if they tried. The only difference between them & me is I'm doing it & their not.
Good job. Nice to see proper use of ferrules, sil wire, heat shrink, etc. Does the transformer quite down if you ground the center caps? One thing that would be good is a sil pad for that MOSFET. Never a good idea to leave a charged transistor sink. If is a giant noise injection system, especially with a motor right behind it. It cost nothing and would make a much safer and professional build. If you did this you could ground the transformer caps and the heat sink and be in good shape from a safety point of view.
Calibration is done close to the upper limit of the range. For 20V that would be between 15V and 20V and for 2A again slightly bellow. If you are concerned about the nonlinearity of the meter then mid range would also work.
My logic was that I need it to be accurate around 3-5V and if I calibrate at that value, it should be accurate there and slightly less accurate when I go up the range due to non-linearity.
Nice built. Reminds ne that i also wanted to build my own (actual i have the parts for 3 different models laying around here but no Time to build them). I like the mounting upside down. Never thought about this bit it could solve some spacing problems.
Hi! great video, informative and professional as always. I might have missed it but you clearly stated in the video that the plastic enclosure was bought from bangood; now i can't find anything like that typing "plastic enclosure" on bangood's search bar and there's no link for that particular item in the description. It would be perfect if you could add the link. Thank you
Thank you for the high quality videos. I am mounting this power supply, and I have a 12v and 7a transformer. Is it possible to use this transformer with this power supply? Thank you very much for your attention.
Funny, I'm also planning to do a Lab PSU with the exakt same PSU Kit, but a more advanced one with two channels (two kits), 2 LCD's + Arduino for data logging and measurements (:
:D thanks! I have a small question: Is it possible to exchange the potentiometers with a PWM signal (filtered through an RC filter + an opamp as buffer) from an μController like an Arduino? I'm thinking about to control the whole PSU with an Arduino, so it can be programmable with a Keypad and some rotary encoders.
I think it's going to be trickier than one would think. This power supply is not designed using the usual topology. Myself I wouldn't waste time on something like that. It would be better to try a different design for that approach.
hm... I had the same concerns (that's why I asked and I don't have so much experience in electronics, I'm a former electrician). I know there are digital potentiometers who can do the job, but I only found 10bit ones, but the resolution with 10 bits (1024 steps) would be ~30mV/~3mA. It's a bit low, but for most things I can think of it would be okey.
I have now stepped back, and bought the same panel meter because I had some problems with the Fan and the Arduino in the same supply line. I know i can decouple this. But for testing purposes i really need a Bench PSU, so I will later build my arduino powered one (: Thanks for the Video :D And as always: keep up the great work! I really enjoy your work and your engagement and passion (:
You should check it for an hour while drawing 3A with low output voltage of a few volts (use low value load resistors). Then measure the temperature of both the heatsink and the transformer. I'm afraid you will see that the transformer gets to a very high temperature because the current into a rectifier with capacitor load is taken by very high current value and narrow pulses that cause much higher heating than what is expected from the average power of 90W. I have checked a number of 3A transformers with disappointing results. Second test is to check the voltage ripple at the output when delivering 30V with 3A .In this case the transformer output voltage sags to lower than 24Vac because of the high current, additionally the main capacitor will have large 100 Hz ripple so at the lower voltage point on the capacitor you won't have enough voltage margin for the regulator. By the way, I can't find in Banggood the beautiful heatsink that you used. I will have to find another big one. Victor Koren
The heatsink I used is recovered from an old PC cpu cooler. I don't plan to use the power supply at 3A, I would of gotten a 4A transformer if I wanted to do that. Mostly this power supply will be used to power stuff at under 1A and occasionally maybe go up to 2A. But I will do some of these stress tests in a future video where I plan a couple of updates for this power supply build. If one really needs a high reliability, low noise, high current linear power supply it should get one of the used HP/Agilents available on ebay.
Very cool indeed, I had planned on building my kit using the same PS board but using an arduino Uno or perhaps a Nano with an lcd display, however after seeing how good that display works I may well buy one of those. I will have to sell off some of my toys to raise the funds for it, perhaps now is the time to get rid of all my Archos collection.
A nice build though I think you have under specified the transformer. You may well lose regulation at higher currents at 30v. The other issue with this kit is one of the op amps is run beyond its maximum voltage rating and the output transistor is at its maximum rating. So this PSU is ok for low current low voltage projects but will probably break under any sort of load. I have a Lamda PSU that supplies 12v at 8amp and that has six 2N3055 pass transistors though that is very much a professional unit still going strong almost 50 years after being built.
I know about the limitations you mentioned, I have read the entire thread on electronics-lab forum where this power supply has been discussed. However in general usage those limitations do not pose a problem. Original 2n3055 are quite robust, The first power supply I ever built was based on this schematic, but with 2n2055 transistor and it's still going after years of service.
Hi and thank you for the detailled presentation. Very good job. I have a question about the P.S. Is there a way to know in advance the limits of the Amps we want to give to a device? I mean, for instance we want to supply a device with max only 1A, eventhough the device at the moment consumes 0.8A. In case that for some reason the current increases, we don't want to give more than 1A. Is there a way to know in advance with the Indicator of the potensiometer where is the limit of 1A?
you could start with the PSU not connected, short the output and adjust the current limit to the desired value. You could also map some values like a silkscreen on the front panel, only rough values, like 0.25A, 0.5A, 0.75A, etc.
Thank you for your answer. Another question please: For a simple laboratory of general purpose, what do you think is better as a bench P.S.? For the same money, as the one you did, a switching P.S. consisted of a switching DC converter 220AC/ 24V dc and a switching module like the DPS 30V 0-3A , or an analog one like the one you did?
I use a larger and noisier fan. An idea for a temp control fan with the LM 2596 board ? , I replaced the 330 ohm resistor next to the 10K pot with a 5 Kohm NTC and glued this sensor to the collector pin of the power transistor (hottest point ) Now the fan only runs full speed when this transistor gets really hot.
I would build a DIY module to do that because modifying existing LM2596 board is harder to do. You can build either a switching regulator with an NTC in the control loop or a linear regulator. There are plenty of schematics available if you google temperature controlled fan circuit.
Hi, there are plenty of on off circuits but that is not good enough, I did not see one where the fan speed is controlled as a function of temp, except arduino pwm control but that is over the edge for most desigs. Do you know one? There are on ebay several commercial for sale those work fine but are bulky and expensive. I have those, my set up is a good alternative. But sure a great idea to DIY I am looking forward for the Voltlog covering that item
the problem itself is not simple because cooling fans have a motor driver and you can't simply pwm the power to the fan. Some will work this way while others will not. You will need an actual variable voltage to obtain the desired effect and that is not an easy job. In one of my designs I am using an inverted buck regulator that is driven with PWM from a microcontroller. (idea was stolen from the 60W dummy load circuit)
Thanks mate for the awesome video, I ordered the same power supply kit as well and this and also the previous video where you assemble the power supply kit was very helpful, I'll post the video up soon, still waiting for the transformer to arrive, and I'll make a separate one for the enclosure as well. Keep up the good work and all the best :) Cheers
Nice video. Im not sure this project gives any advantage to buying a cheap gophert power supply reviewed on this site, except of course if not for the fun of it.
But this linear supply is much less noisy than the Gophert supply. So for projects where you need a clean power source, this one could be worth the time and money.
My idea was to use an old MOT, instead of buying line cord and fuse, just use the cord from the Microwave, it includes a fuse. Im not a fan of DYI for the fun of it the only advantage would be if it breaks you can fix it easily.
Great video. Any future plans for a bluetooth speaker? I remember you mentioning it quite a while back. I'd be really interested to see what you do with some of those csr chips.
Hi, In one of your 'InTheMail' videos you mentioned that you would be using a 1A Fast Blow fuse for this power supply. I thought it was normal to use a Slow Blow fuse on the power input. Is that not your understanding? Nice work by the way and good video as always.
The transformer part number is Indel TST 80/003. It is sold by a couple of distributors in Romania, Bulgaria, Poland. Try a google search and see if you find anything close to you because buying it internationally is not a good option.
why is it hard to get a power supply with more current? i mean 30V is nice, but i dont like the current limit for lower voltages. i wish there was a cheap module which could take any kind of mosfet for switching and you could adjust the max current
Thanks for all the great videos you post for us. It's always very interesting and inspiring to watch your content. Keep up the great work! btw: do you have a subscriber goal for this year?
Nice job. Thanks for taking the time to show how you did that. For what it's worth, I cut out panels the same way. The only difference is I drill out the corners first, & then file out the fine details. I have lots of different tools at hand, but that seems to work pretty good for me.
Thank you for watching! I think I suck at mechanical work :)
Like anything else. Practice & persistence. People around me think that I am smart ( I fooled them)
because I build electronic things like you. A few years ago I didn't even know how to open a laptop computer, let alone use it. Now I'm building a CNC machine. I tell them they could do it to if they tried.
The only difference between them & me is I'm doing it & their not.
It's nice to hear you got into electronics this way, without any background. Thank you for watching my videos.
Good job. Nice to see proper use of ferrules, sil wire, heat shrink, etc. Does the transformer quite down if you ground the center caps?
One thing that would be good is a sil pad for that MOSFET. Never a good idea to leave a charged transistor sink. If is a giant noise injection system, especially with a motor right behind it.
It cost nothing and would make a much safer and professional build.
If you did this you could ground the transformer caps and the heat sink and be in good shape from a safety point of view.
Calibration is done close to the upper limit of the range. For 20V that would be between 15V and 20V and for 2A again slightly bellow. If you are concerned about the nonlinearity of the meter then mid range would also work.
My logic was that I need it to be accurate around 3-5V and if I calibrate at that value, it should be accurate there and slightly less accurate when I go up the range due to non-linearity.
Nice built. Reminds ne that i also wanted to build my own (actual i have the parts for 3 different models laying around here but no Time to build them). I like the mounting upside down. Never thought about this bit it could solve some spacing problems.
it took me a full day to figure out how to mount everything and still get adequate cooling :)
Will you make video on connecting the panel meter to the buck converter?
Another great video. I never thought of mounting to the top cover. Great idea!
thanks!
Hi! great video, informative and professional as always.
I might have missed it but you clearly stated in the video that the plastic enclosure was bought from bangood; now i can't find anything like that typing "plastic enclosure" on bangood's search bar and there's no link for that particular item in the description. It would be perfect if you could add the link.
Thank you
sorry, I just added a link in the description for the plastic enclosure.
thanks again! keep up the amazing work!
Thank you for the high quality videos. I am mounting this power supply, and I have a 12v and 7a transformer. Is it possible to use this transformer with this power supply? Thank you very much for your attention.
yes, it will work, reaching lower max voltage.
Many thanks for the quick reply. I was in doubt whether the larger current generated by the transformer could damage the power suppy.
Funny, I'm also planning to do a Lab PSU with the exakt same PSU Kit, but a more advanced one with two channels (two kits), 2 LCD's + Arduino for data logging and measurements (:
Nice. Good luck on your project!
:D thanks! I have a small question: Is it possible to exchange the potentiometers with a PWM signal (filtered through an RC filter + an opamp as buffer) from an μController like an Arduino? I'm thinking about to control the whole PSU with an Arduino, so it can be programmable with a Keypad and some rotary encoders.
I think it's going to be trickier than one would think. This power supply is not designed using the usual topology. Myself I wouldn't waste time on something like that. It would be better to try a different design for that approach.
hm... I had the same concerns (that's why I asked and I don't have so much experience in electronics, I'm a former electrician). I know there are digital potentiometers who can do the job, but I only found 10bit ones, but the resolution with 10 bits (1024 steps) would be ~30mV/~3mA. It's a bit low, but for most things I can think of it would be okey.
I have now stepped back, and bought the same panel meter because I had some problems with the Fan and the Arduino in the same supply line. I know i can decouple this. But for testing purposes i really need a Bench PSU, so I will later build my arduino powered one (:
Thanks for the Video :D And as always: keep up the great work! I really enjoy your work and your engagement and passion (:
So how has the case held up against the heat? Any warping?
very well so far, no warping but I've got a decent heatsink with a fan taking care of that..
VoltLog Thanks good to know - I have four of those cases awaiting future projects ;)
You should check it for an hour while drawing 3A with low output voltage of a few volts (use low value load resistors). Then measure the temperature of both the heatsink and the transformer. I'm afraid you will see that the transformer gets to a very high temperature because the current into a rectifier with capacitor load is taken by very high current value and narrow pulses that cause much higher heating than what is expected from the average power of 90W. I have checked a number of 3A transformers with disappointing results.
Second test is to check the voltage ripple at the output when delivering 30V with 3A .In this case the transformer output voltage sags to lower than 24Vac because of the high current, additionally the main capacitor will have large 100 Hz ripple so at the lower voltage point on the capacitor you won't have enough voltage margin for the regulator.
By the way, I can't find in Banggood the beautiful heatsink that you used. I will have to find another big one.
Victor Koren
The heatsink I used is recovered from an old PC cpu cooler. I don't plan to use the power supply at 3A, I would of gotten a 4A transformer if I wanted to do that. Mostly this power supply will be used to power stuff at under 1A and occasionally maybe go up to 2A. But I will do some of these stress tests in a future video where I plan a couple of updates for this power supply build. If one really needs a high reliability, low noise, high current linear power supply it should get one of the used HP/Agilents available on ebay.
Very cool indeed, I had planned on building my kit using the same PS board but using an arduino Uno or perhaps a Nano with an lcd display, however after seeing how good that display works I may well buy one of those. I will have to sell off some of my toys to raise the funds for it, perhaps now is the time to get rid of all my Archos collection.
Good luck with the project, it should turn out nice.
A nice build though I think you have under specified the transformer. You may well lose regulation at higher currents at 30v. The other issue with this kit is one of the op amps is run beyond its maximum voltage rating and the output transistor is at its maximum rating. So this PSU is ok for low current low voltage projects but will probably break under any sort of load. I have a Lamda PSU that supplies 12v at 8amp and that has six 2N3055 pass transistors though that is very much a professional unit still going strong almost 50 years after being built.
I know about the limitations you mentioned, I have read the entire thread on electronics-lab forum where this power supply has been discussed. However in general usage those limitations do not pose a problem. Original 2n3055 are quite robust, The first power supply I ever built was based on this schematic, but with 2n2055 transistor and it's still going after years of service.
Will you do some measurements on the noise etc of this psu?
yes I will do some measurement in a future video.
great built as usual. always informative and always a nice clean job fantastic. ..brilliant channel keep it up my friend. ...UK subscriber 😊
thank you for watching!
Hi and thank you for the detailled presentation. Very good job. I have a question about the P.S. Is there a way to know in advance the limits of the Amps we want to give to a device? I mean, for instance we want to supply a device with max only 1A, eventhough the device at the moment consumes 0.8A. In case that for some reason the current increases, we don't want to give more than 1A. Is there a way to know in advance with the Indicator of the potensiometer where is the limit of 1A?
you could start with the PSU not connected, short the output and adjust the current limit to the desired value. You could also map some values like a silkscreen on the front panel, only rough values, like 0.25A, 0.5A, 0.75A, etc.
Thank you for your answer. Another question please: For a simple laboratory of general purpose, what do you think is better as a bench P.S.? For the same money, as the one you did, a switching P.S. consisted of a switching DC converter 220AC/ 24V dc and a switching module like the DPS 30V 0-3A , or an analog one like the one you did?
The analog one is better for laboratory use because of the lower noise.
Thank you. Best regards.
But, do you mean the physical noise that can annoys the ears or the rippling frequency at the signal?
Hi . I have build the same circit but the problem is that is stack at 26 vdc. I tyred to change the voltage but nothing changes. What i have to do ?
I use a larger and noisier fan. An idea for a temp control fan with the LM 2596 board ? , I replaced the 330 ohm resistor next to the 10K pot with a 5 Kohm NTC and glued this sensor to the collector pin of the power transistor (hottest point ) Now the fan only runs full speed when this transistor gets really hot.
I would build a DIY module to do that because modifying existing LM2596 board is harder to do. You can build either a switching regulator with an NTC in the control loop or a linear regulator. There are plenty of schematics available if you google temperature controlled fan circuit.
Hi, there are plenty of on off circuits but that is not good enough, I did not see one where the fan speed is controlled as a function of temp, except arduino pwm control but that is over the edge for most desigs. Do you know one? There are on ebay several commercial for sale those work fine but are bulky and expensive. I have those, my set up is a good alternative. But sure a great idea to DIY I am looking forward for the Voltlog covering that item
the problem itself is not simple because cooling fans have a motor driver and you can't simply pwm the power to the fan. Some will work this way while others will not. You will need an actual variable voltage to obtain the desired effect and that is not an easy job. In one of my designs I am using an inverted buck regulator that is driven with PWM from a microcontroller. (idea was stolen from the 60W dummy load circuit)
You should try using a nibbler because you will get better results with it
Nice video. Do you have a link for the plastic enclosure?
sorry, I just added a link in the description for the plastic enclosure.
can not get plastic Enclosure & can not get VAM 9020 front panel Meter from Banggood dos not have
Thanks mate for the awesome video, I ordered the same power supply kit as well and this and also the previous video where you assemble the power supply kit was very helpful, I'll post the video up soon, still waiting for the transformer to arrive, and I'll make a separate one for the enclosure as well. Keep up the good work and all the best :) Cheers
Great video. This Toroidal Transformer only puts out 3 amp, is that really enough for a benchtop?
it depends on what types of circuits you working on
Nice video. Im not sure this project gives any advantage to buying a cheap gophert power supply reviewed on this site, except of course if not for the fun of it.
It was fun to build it for sure :)
But this linear supply is much less noisy than the Gophert supply. So for projects where you need a clean power source, this one could be worth the time and money.
My idea was to use an old MOT, instead of buying line cord and fuse, just use the cord from the Microwave, it includes a fuse. Im not a fan of DYI for the fun of it the only advantage would be if it breaks you can fix it easily.
hi there im building the same kit here but im a little confused with where to wire in the dc to dc convertor cheers peter uk
10:05 is where I talk about that.
Nice wideo as allways.
Why not use the onboard fan power supply, changing the 24v regulator to 12v
I did not have a compatible 12V regulator at that time.
So the current is calibrated by short circuiting the PSU with multimeter, no external load?
Are you sure that rocker switch is rated for mains voltage? I seem to recall that they are meant for 12/24V DC type applications.
It is rated for mains voltage, it was salvaged from an ATX power supply.
Ah, okay, should be safe then! Thanks for a great video!
Could not see how your pot's are wired from video. Could you tell me which colors go on what terminal on the pot?
Great video. Any future plans for a bluetooth speaker? I remember you mentioning it quite a while back. I'd be really interested to see what you do with some of those csr chips.
Yes, I still have that project on my todo list.
Hi, In one of your 'InTheMail' videos you mentioned that you would be using a 1A Fast Blow fuse for this power supply. I thought it was normal to use a Slow Blow fuse on the power input. Is that not your understanding? Nice work by the way and good video as always.
yes, a slow blow fuse would be better. I just couldn't find them for the same price on ebay. At 1A ceramic, slow blow seemed to cost twice as much.
🤔 a link for purchasing the toroid please?
The transformer part number is Indel TST 80/003. It is sold by a couple of distributors in Romania, Bulgaria, Poland. Try a google search and see if you find anything close to you because buying it internationally is not a good option.
Hai, great video..Where can i find the .PDF File
what PDF are you searching for?
The one with the layout of the front panel.
here is the pdf file link voltlog.com/pub/front-back-panel-drawing.pdf
Thank you very much...
Nice build and great detail!
thank you for watching!
why is it hard to get a power supply with more current? i mean 30V is nice, but i dont like the current limit for lower voltages. i wish there was a cheap module which could take any kind of mosfet for switching and you could adjust the max current
I think it's always a trade-off between noise and power, higher power higher noise, lower power lower noise.
is there any transformers that will work similar to the one you used there? the lowest price I could find is $55 and I'm not paying that much.
Have you tested this power supply (after assembly) more deeply, like gophert product ?
Nope, all the info you could possible want to know about this power supply has already been tested & discussed on the forums.
Thank you so much for the links . Great video thanks
You first changed range to amps and then just reconnect probes cables ^^ You aren't afraid of doing that?
not a problem :-)
the output is -0.65 what u can do
Change that transistor to a better one. Like a 200watt one atleast. Or 300watt.
Nice build.
Nice build!
And the display can't show t° ? Bummer...
That should be suitable.
This panel meter does not show temperature.. it would have been useful.
i think the box link is missing... btw, great video! I'll adding stuff to my shopping cart :D
and the toroidal transformer is missing, too ;)
sorry, I just added a link in the description for the plastic enclosure. The transformer was purchased locally, no link for that one.
Good project, nice video.
Thank you for watching!
Thanks for all the great videos you post for us. It's always very interesting and inspiring to watch your content. Keep up the great work!
btw: do you have a subscriber goal for this year?
Thank you. I would like to reach 5k subscribers by the end of this year.
I hope that you reach your goal and that you go even further! :)
I will do my best to reach my goals! thank you!
Analog??? I thought is Digital Meter?
Good project
the only thing I didn't have is the transformer
but avesome video
Nice build!
thank you!