I'm an insatiable kit builder when I can afford the time and expense, so, when I saw this cheap kit with some potentially mysterious features, I couldn't resist the temptation. The lack of printed paper instructions wasn't a problem, as the silk-screen on the PCB is adequate enough to let you see where to put things, so the overall build was trouble-free. Then came the power-up test ... when I switched the unit on I could see more clearly the function and capability of the "other features" built into this unit, and I could also test the actual PSU to see what it could do. So, regarding "those features", there's a pulsed square-wave output that one can use externally for situations that need some form of clock-pulse; for example, as a source for the drive pulse to a stepper-motor. Then there's a logic-level tester, which might be useful for beginners, but will only work correctly if the output of the PSU itself is set past 5v. Then there's a facility that I'd call ... "the positive voltage present test", where a buzzer sounds if a positive voltage is probed for and found. I have to say here that, all of these things; the pulse source, the logic level tester, and the positive voltage level tester, are superfluous to the basic function of this PSU. In fact, you can happily take out the 4069 CMOS chip and operate the unit as a straightforward PSU if you like. It seems to me a bit strange that these things, which are in fact rather inadequate for the jobs they seem to be intended for, were included in the first place ... perhaps the "designer" was looking for some reason to have flashing lights inside this transparent box, I don't know! Now to the PSU itself ... Well, the transformer as supplied is not adequate for the job; it's only capable of delivering around 0.5A, whereas the LM317 is able to handle a good deal more current than that. That being the case, here's what I did ... I swapped out the original transformer for one that had a higher current rating of 2A, but still at 12v. In my case, the replacement transformer was just a little bit physically larger than the original, so I was lucky that it fitted inside the box without a problem. If anyone else does this kind of modification, I suggest sticking strictly to a 12v transformer; the reason being that, the 4069 CMOS chip is supplied directly from the "variable output" of this PSU (a bad design, I have to say), so if you use a replacement transformer that is rated higher than 12v, and if you keep the 4069 in-circuit, then you will be in great danger of blowing it up if you exceed 15v or so on the output. That, ladies and gentlemen, is the account of my own experience with this enjoyable, semi-useful, and at the cheap price that is asked, recommendable kit.

I'm an insatiable kit builder when I can afford the time and expense, so, when I saw this cheap kit with some potentially mysterious features, I couldn't resist the temptation. The lack of printed paper instructions wasn't a problem, as the silk-screen on the PCB is adequate enough to let you see where to put things, so the overall build was trouble-free. Then came the power-up test ... when I switched the unit on I could see more clearly the function and capability of the "other features" built into this unit, and I could also test the actual PSU to see what it could do. So, regarding "those features", there's a pulsed square-wave output that one can use externally for situations that need some form of clock-pulse; for example, as a source for the drive pulse to a stepper-motor. Then there's a logic-level tester, which might be useful for beginners, but will only work correctly if the output of the PSU itself is set past 5v. Then there's a facility that I'd call ... "the positive voltage present test", where a buzzer sounds if a positive voltage is probed for and found. I have to say here that, all of these things; the pulse source, the logic level tester, and the positive voltage level tester, are superfluous to the basic function of this PSU. In fact, you can happily take out the 4069 CMOS chip and operate the unit as a straightforward PSU if you like. It seems to me a bit strange that these things, which are in fact rather inadequate for the jobs they seem to be intended for, were included in the first place ... perhaps the "designer" was looking for some reason to have flashing lights inside this transparent box, I don't know! Now to the PSU itself ... Well, the transformer as supplied is not adequate for the job; it's only capable of delivering around 0.5A, whereas the LM317 is able to handle a good deal more current than that. That being the case, here's what I did ... I swapped out the original transformer for one that had a higher current rating of 2A, but still at 12v. In my case, the replacement transformer was just a little bit physically larger than the original, so I was lucky that it fitted inside the box without a problem. If anyone else does this kind of modification, I suggest sticking strictly to a 12v transformer; the reason being that, the 4069 CMOS chip is supplied directly from the "variable output" of this PSU (a bad design, I have to say), so if you use a replacement transformer that is rated higher than 12v, and if you keep the 4069 in-circuit, then you will be in great danger of blowing it up if you exceed 15v or so on the output. That, ladies and gentlemen, is the account of my own experience with this enjoyable, semi-useful, and at the cheap price that is asked, recommendable kit.

I'm an insatiable kit builder when I can afford the time and expense, so, when I saw this cheap kit with some potentially mysterious features, I couldn't resist the temptation. The lack of printed paper instructions wasn't a problem, as the silk-screen on the PCB is adequate enough to let you see where to put things, so the overall build was trouble-free. Then came the power-up test ... when I switched the unit on I could see more clearly the function and capability of the "other features" built into this unit, and I could also test the actual PSU to see what it could do. So, regarding "those features", there's a pulsed square-wave output that one can use externally for situations that need some form of clock-pulse; for example, as a source for the drive pulse to a stepper-motor. Then there's a logic-level tester, which might be useful for beginners, but will only work correctly if the output of the PSU itself is set past 5v. Then there's a facility that I'd call ... "the positive voltage present test", where a buzzer sounds if a positive voltage is probed for and found. I have to say here that, all of these things; the pulse source, the logic level tester, and the positive voltage level tester, are superfluous to the basic function of this PSU. In fact, you can happily take out the 4069 CMOS chip and operate the unit as a straightforward PSU if you like. It seems to me a bit strange that these things, which are in fact rather inadequate for the jobs they seem to be intended for, were included in the first place ... perhaps the "designer" was looking for some reason to have flashing lights inside this transparent box, I don't know! Now to the PSU itself ... Well, the transformer as supplied is not adequate for the job; it's only capable of delivering around 0.5A, whereas the LM317 is able to handle a good deal more current than that. That being the case, here's what I did ... I swapped out the original transformer for one that had a higher current rating of 2A, but still at 12v. In my case, the replacement transformer was just a little bit physically larger than the original, so I was lucky that it fitted inside the box without a problem. If anyone else does this kind of modification, I suggest sticking strictly to a 12v transformer; the reason being that, the 4069 CMOS chip is supplied directly from the "variable output" of this PSU (a bad design, I have to say), so if you use a replacement transformer that is rated higher than 12v, and if you keep the 4069 in-circuit, then you will be in great danger of blowing it up if you exceed 15v or so on the output. That, ladies and gentlemen, is the account of my own experience with this enjoyable, semi-useful, and at the cheap price that is asked, recommendable kit.

Bought it because it reminded me of a ps kit I built as a kid some... 50 years ago. All parts were there, and it came together perfectly in about two hours of fun. The wires for the output are way too short, so I replaced them with longer ones. The box is actually a very strange combination of three unrelated items: - variable DC power supply - square wave signal generator - high/low buzzer & LED sensor The second two circuits are powered by the first, so their function is somewhat dependant. The capacitor in the square wave generator's RC circuit is not strict regarding electrolitic polarity. And one LED stays on when it should go off in the high/low sensing circuit. But in general, and mostly in its' primary function of power supply - it's perfectly OK! Fun. Cool. Cheap.... Great job!

Bought it because it reminded me of a ps kit I built as a kid some... 50 years ago. All parts were there, and it came together perfectly in about two hours of fun. The wires for the output are way too short, so I replaced them with longer ones. The box is actually a very strange combination of three unrelated items: - variable DC power supply - square wave signal generator - high/low buzzer & LED sensor The second two circuits are powered by the first, so their function is somewhat dependant. The capacitor in the square wave generator's RC circuit is not strict regarding electrolitic polarity. And one LED stays on when it should go off in the high/low sensing circuit. But in general, and mostly in its' primary function of power supply - it's perfectly OK! Fun. Cool. Cheap.... Great job!

Bought it because it reminded me of a ps kit I built as a kid some... 50 years ago. All parts were there, and it came together perfectly in about two hours of fun. The wires for the output are way too short, so I replaced them with longer ones. The box is actually a very strange combination of three unrelated items: - variable DC power supply - square wave signal generator - high/low buzzer & LED sensor The second two circuits are powered by the first, so their function is somewhat dependant. The capacitor in the square wave generator's RC circuit is not strict regarding electrolitic polarity. And one LED stays on when it should go off in the high/low sensing circuit. But in general, and mostly in its' primary function of power supply - it's perfectly OK! Fun. Cool. Cheap.... Great job!