What's the working principle of this inverter circuit ?

[ntr97]

How to fix voltage drops at 220V in this inverter Circuit

How can i fix the voltage at 220V , when I connect the voltmetre with no load it shows 220V but when I add a lamp it drops to 87V
What can I do to improve the circuit and what are your opinions about it
Help please !

 

[KlausST]

Re: How to fix voltage drops at 220V in this inverter Circuit

Hi,

You just need ti find out where the voltage drop is...

This is a simulation, so why don't you use the features and measure primary voltages?
Or use a scope... to see more details.

Klaus

 

[Easy peasy]

Re: How to fix voltage drops at 220V in this inverter Circuit

what is your power source? a battery that sags? what is the resistance of the primary and secondary windings, these will have an IR drop, is the duty cycle of the converter 49% + 49% or some other value? at no load the energy stored in the Tx is available to the o/p during the dead time, raising Vo, when loaded this energy does not add to the Vo significantly ...

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are you overloading the output with 12V lamps, and then getting IR drop in the fets?

 

[E-design]

Re: How to fix voltage drops at 220V in this inverter Circuit

You are most probably using the default values for your transformer and wrong inductance ratios. If you calculate the correct values against desired frequency, then it should work as shown below.

 

[ntr97]

Re: How to fix voltage drops at 220V in this inverter Circuit

You are most probably using the default values for your transformer and wrong inductance ratios. If you calculate the correct values against desired frequency, then it should work as shown below.

Hi ! Thanks for your answer
But how can I calculate it , ( my timer is at 50hz frequency )
Also , will the voltage be fixed at 220V ?
the power you calculated ( 266 VA ) using the wattmeter , is it the max power of the inverter ?
do i have to change the winding resistance of the transformer ( they are both at 1m by default )
Thank you

 

[E-design]

Re: How to fix voltage drops at 220V in this inverter Circuit

Well, the maximum power will be determined by the maximum switching currents of the power FETs. The winding turn's ratio will establish the maximum available output voltage.

At the moment of turning on, there is a high-current period until the operating level is established. Your FET's should be able to handle the operating current without exceeding the safe specifications. As you can see if we reduce the load resistance, the power increase to 462 VA and the voltage drops to 190 VAC. This is an indication that we are over the power capability of this design. Limitation will be a combination of the FET's, transformer size, wire resistance, etc.

 

[Audioguru]

Re: How to fix voltage drops at 220V in this inverter Circuit

The extremely simple circuit is missing a voltage regulator circuit. Then its output voltage will not be fixed at 220V, it will be too high or too low with no load and it will drop (down to 190V or less) when loaded.

 

[ntr97]

I can't read this whole circuit , can you explain it to me
thanks