Hello,

A while ago I posted here https://forum.allaboutcircuits.com/...p-powe-supply-mc34063adr.189461/#post-1766996
to help me design a 24V to 34V converter for my project.
Now that the PCBs have arrived i tried to assemble jsut the power supply unit first, and after soldering on all of its components except the power supply itself (MC34063ADR2G), it seemed everything was ok. There was no short circuits, the current was 0 and the output voltage was the same as input (24V), which is normal since there is nothing switching it.

Then i added the MC34063ADR2G and the current was 0.6A at just 8V input voltage! Something is clearly not correct here, and after i checked again for short circuits and determening that everything is ok, i now need help with what could be wrong here.
Is there a component that could be faulty? is there a part thats over/under powered for this?

Here is a picture of the schematic and layout:

 

hi kram,
This is what LTSpice shows for that circuit, I have added a 100R load.
Check my circuit for accuracy.
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hi,
A very rough check on the PCB artwork , looks OK.??
E

 

Greatings,
Thank you for your simulation. It helped me verify the integrity of the circuit.
I have found the problem, which was the capacitors, which were only rated for 16V (wrong part bag). After replacing them with 40V capacitors the circuit works perfectly and only draws 10mA at 34V.

Thanks for the help

 

hi kram,
I would suggest you learn LTSpice, it is very useful for verifying your designs, it is also free
E