I
isr
Guest
I was wondering if someone could hazard a guess as to what sort
of power supply circuit I have. Here are the clues:
- voltage 0-15V
- current 0-3A with current limit facility/dial
- input voltage 230V 50Hz (i.e. Europe system)
- there is a large heat sink with two 2N3055 power T's connected in parallel
- when the voltage is increased above around 6V there is an audiable click
due to the relay inside, see picture
- there are 4 diode bridge circuits, see top left, top right, and two at bottom right,
see picture
- other active components are L7809CV x 2, L7812C, LM741CN,
D313, LM324N, C1008 x 2, TL431C, see picture
- the transformer seems to have 4 outputs, i.e. 2 lots of three wires plus two lots
of 2 wires
- picture of pcb is here : http://www.geocities.com/psuinternals/psu.jpg
I am curious as to how this psu works, and I was hoping someone would
know looking at the above points and save me to try and recreate the
schematic. Also, it seems this circuit does not use one of the more modern
ic's such as the L200C and instead uses fixed regulators such as the L7809 9v
regulator, the L7812 12v regulator, plus 4 op amps in LM324N plus another
741 op amp. Why anyone would want to use a 741 nowadays is a mystory.
Also used is a variable zener diode - TL431C, and 2 bipolar T's - C1008.
of power supply circuit I have. Here are the clues:
- voltage 0-15V
- current 0-3A with current limit facility/dial
- input voltage 230V 50Hz (i.e. Europe system)
- there is a large heat sink with two 2N3055 power T's connected in parallel
- when the voltage is increased above around 6V there is an audiable click
due to the relay inside, see picture
- there are 4 diode bridge circuits, see top left, top right, and two at bottom right,
see picture
- other active components are L7809CV x 2, L7812C, LM741CN,
D313, LM324N, C1008 x 2, TL431C, see picture
- the transformer seems to have 4 outputs, i.e. 2 lots of three wires plus two lots
of 2 wires
- picture of pcb is here : http://www.geocities.com/psuinternals/psu.jpg
I am curious as to how this psu works, and I was hoping someone would
know looking at the above points and save me to try and recreate the
schematic. Also, it seems this circuit does not use one of the more modern
ic's such as the L200C and instead uses fixed regulators such as the L7809 9v
regulator, the L7812 12v regulator, plus 4 op amps in LM324N plus another
741 op amp. Why anyone would want to use a 741 nowadays is a mystory.
Also used is a variable zener diode - TL431C, and 2 bipolar T's - C1008.