replicating an old circuit- unexpected voltage drop

[jabba99]

I'm fairly new to circuit design and i stumbled upon this old fashioned circuit everything is fine on the breadboard but i was surprised when i put it on the pcb that whenever i put a resistor parallel to the 10V line ( i need it for the rest of the circuit) the voltage drops to about 4V. I triple checked everything and it's fine. any tips on what could be the issue?

 

[LionelHutz]

Right back to my first post. It's a voltage divider.

I now find it very hard to believe that the circuit with the load connected works on a breadboard.

 

[jabba99]

it does work as i said when i put the entire circuit on the breadboard i get the results put the PCB has an issue

I'm starting to think that the traces aren't wide enough and could be affecting the circuit. I'm using 0,3mm thoughout the entire board.

 

[LionelHutz]

The load can't be 560 ohms then.

It doesn't compute. 560ohm load with that 56k series resistor means that less than 0.9% of the input voltage gets applied to the load. Say you were able to use the full peak of the applied 230VAC. That is 325V peak and 0.9% is 2.9V.

You've got a scope. Compare the breadboard and PC board version and determine where the issue is.

 

[IRstuff]

Based on your scope measurement, the resistance has to ~1200 ohms. However, that's still below the zener voltage because even 1200 ohm is too large a load for the 56k resistor

TTFN (ta ta for now)
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