Voltage multiplier balancing issues

Thread Starter

SiCEngineer

Joined May 22, 2019
442
Hi All,

I am designing an SMPS and have an issue with my output voltages. I am using a voltage quadrupler to boost my transformer output by 4x. I will attach a schematic of the multiplier rectifier to this thread.

My issue is that, although I expect 800V and 400V at my output for the two loads, they are quite imbalanced. I get 829V and 407V, which is quite the difference. I have tried multiple changes to my schematic but the imbalance seems to remain. The diodes are ideal, as are the capacitors.

Any suggestions for these discrepencies would be appreciated!

Capacitors are 100nF each.
 

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KeithWalker

Joined Jul 10, 2017
3,063
Hi All,

I am designing an SMPS and have an issue with my output voltages. I am using a voltage quadrupler to boost my transformer output by 4x. I will attach a schematic of the multiplier rectifier to this thread.

My issue is that, although I expect 800V and 400V at my output for the two loads, they are quite imbalanced. I get 829V and 407V, which is quite the difference. I have tried multiple changes to my schematic but the imbalance seems to remain. The diodes are ideal, as are the capacitors.

Any suggestions for these discrepencies would be appreciated!

Capacitors are 100nF each.
What are the values of R6 and R7? Your circuit is not symmetrical so why would you expect it to be balanced?
R6 is connected across the positive supply but there is no resistor connected across the negative supply. R7 is connected between positive and negative.
 

Thread Starter

SiCEngineer

Joined May 22, 2019
442
What are the values of R6 and R7? Your circuit is not symmetrical so why would you expect it to be balanced?
R6 is connected across the positive supply but there is no resistor connected across the negative supply. R7 is connected between positive and negative.
I have one resistor across the positive and negative supply to get 4x the output voltage of transformer. The other resistor is connected across just the positive supply so that I get 2x the output voltage of the transformer. I originally had this as two secondary windings each feeding a full wave voltage multiplier, with one resistor connected across one voltage multiplier and the other resistor connected across both of the voltage multipliers. In that configuration, I didn’t have this issue. But the Essence of what I was trying to do is the same, but without the extra secondary winding. So I’m unsure what is different.

The resistor values are 10.5kOhm for the 400V output and the 800V output resistor is 270Ohm.
 

AlbertHall

Joined Jun 4, 2014
12,345
All four capacitors are 100nF?
What frequency is this circuit running at?
Is the resistor across the 800V output really 270Ω (3A, 2.4kW)?
 
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