sparky666

I forgot to mention that I connected a light bulb from a car which had approx. 1ohm resistance, and the project was working normally(min voltage 0.0V, max voltage 30.0V and max load 3A), so I'm totally out of guesses what is wrong...

I measured the voltage of the project with a 10k resistor since that resistor was in hand, and the min voltage was 1.1V and the max was 30V, without it, it the min was 6.4V and the max 30V;with the output shorted,the min was 0.0V, but the max was 0.3V. And the two 2n3055 transistors that I use are connected with the right pins

Audioguru! I made the measurements as you said. With the voltage pot set to 0, and the current pot at max, the output voltage of the project is 6.1-6.2V, the voltages at U1 : pin1,4,5 0V, pin2 1.9V, pin3 -0.5V, pin6 0.01V, pin7 36V. The voltages at U2: pin1,2,3,4 0V, pin6 0.01V, pin7 36V. The voltages at U3: pin1 -1.4V, pin2,3 0V, pin4 -1.4V, pin5 -1.5V, pin6 -1.1V and at pin7 26.2V.

Hi again! The supply is the latest version with mc34071. The voltage at U3's pin4 is -1.5V. In my region, we call heli pot a potentiometer with multiple turns(12 turns for me).

Hi guys! I have recently built the supply, but I have two major problems: Firstly I could set the upper limit of the voltage to 30 V, but the lower limit stays at 5.6V no mater what I do, and at this voltage the LED is on, and if I switch to the max current limit, then the voltage jumps from 5.6 to 12V. The second problem is that the voltage regulator pot is a 10k heli pot, and at the half way the voltage is at max, and furthermore I can't raise the upper limit. The supply itself works great at higher voltages then 5.6V, so I can't figure out what is wrong. Any help would be appreciated.

I would like to build this power supply too. Now I'm making the PCB design for bottom layer only PCB, when I saw that something's wrong with U1(I think). The Vcc+ pin is at the In- side, and the Vcc- at the In+ side. How is that IC placed there? And one more thing: Can I use TL071CP instead of TLE2141(They are pin compatible, they do the same thing, the price is different)? Any help would be appreciated.