Power Inverter circuit related to transformer

[prayami]

Hi...

We are making Power Inverter for getting variable output from 12V to 30V with 12V input. Everything working fine but when we connect some register at the output the output voltage doesnot go to desire voltage but little bit less than desire. For example if desire output is 25V the actual output is 24.4V and does not go above that even continuous pulses are applied. The pulses coming out from MOSFET are having spikes and noise. We are using 18F2420 microprocessor from Microchip.

One analog chanel I used as current voltage and one variable register to another analog chanel for desire voltage. When current voltage goes above desire voltage the pulses applied to MOSFET are stopped. And if current voltage is less than desire voltage then pulses are given continuosly.

Pulse frequency is around 20Khz. There is 5us delay between turning ON and OFF of both the MOSFET.


Thanks...

 

[stanley1985]

May be the transfomer leakage inductor cause this problem.

 

[babinton]

Hi,

I think you should check for loading effect at the connection to the register, if the impedance present by the register to the output of the inverter is not properly matched to the output impedance of the inverter, it might cause drop in voltage that you are experience. Try using a buffer , and if that didn't work , try using a snubber circuit (between the collector and emitter or source and drain of the power transistor if you use one in your inverter).
regards.