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Pawel_K
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Posts posted by Pawel_K
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Which opamps should I buy ??
MC34071AP ??
TLE2141CP ?? -
Hi Omni
I checked R7 and its R47 = 0,47 Ohm
R1 resistor is 1W.
I used in my project the trafo 25,6V.
Audioguru Can you help me ?? -
I checked voltages with U1,U2,U3 removed.
Pin7 of all opamps is 34,4V
Pin4 of U2 and U3 is -7,2V
Pin6 of U1 is 0V
Pin6 of U3 is 35,5V
Now D10 diode is not hot.
Resistor R1 is hot.
I changed in my project:
C1 capacitor with 4700uF/50V
D11 with 1N4007
Q1 with BC547
Q2 wth BD139-16
TL081 with OP07
There are photos of my PCB:
[img width=680 height=511]http://free.of.pl/p/pawel-kolodziej/2.JPG
Please help me. ??? -
I checked PCB and it looks ok.
Diode D10 is very hot.
I checked also rest of elements and they are ok. -
Voltages with removed U3:
between 3pin and GND minus 29V
between 3pin and + also minus 29V
between 2pin and + 0V
between 2pin and - 0V
Here is the opamp tester.
When I put U3 into the tester the diode flash. -
GND-PIN2 0V
GND-PIN3 2,5V
GND is "-" on the PCB ?? -
Voltage on U3 PIN2,3 is 2,5V
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I checked voltages.
Pin 7 of all the opamps is +32,2V
Pin 4 of U2 and U3 is -7,1V
Pin 6 of U1 is +10,5VDC
Pin 6 of U3 is -4,7V
current limit diode is lighting all the time.
When the 2N3055 wasn't solder I could regulate output voltage from 0,1V to 1V.
Now after solder 2N3055 I can't regulate output voltage. It's -0,6V. :-\ -
Hi
It's my first post on this forum.
I built this power supply, but it doesn't ot work.
I changed TL081 with uA741.
I also changed 2N2219 with BD139-16.
I can regulate voltage from 0,1 to 1V. :-[
Sorry for my english.
0-30 Vdc Stabilized Power Supply
in Projects Q/A
Posted
I can't buy this opamps in my area :-[
Something more popular ??