Boost converter VOltage out dropping slowly

[nafnaf]

i make a boost converter 500hz 15 to 30v but as i simulate it the output voltage drops slowly
why my voltage drops slowly in out instead of constant 30v
thanks

 

[shatruddha]

Circuit diagram of your converter will be required to debug the issue

 

[BradtheRad]

On power-up, it is typical for the output to overshoot your designed volt level.

Also for it to wander up and down for a few cycles. This is due to LC resonant action of the coil and capacitor.

Simulation with scope traces. Values were chosen to boost 15V to 30V at 1 A, and an operating frequency of 500 Hz.

 

[nafnaf]

here

 

[FvM]

What you see in the waveform is the initial transient response, caused by charging the output capacitor through the boost inductor. There's no controlled boost operation involved so far.

To prevent this transient, which can cause unwanted overvoltage at the output, you can use a bypass diode from input to output.

 

[nafnaf]

i simulate it in simetrix this why is that it suddenly stops in 1 sec not in my 5 secs selected time

thanks

 

[chuckey]

There is no load on the PSU. In the last circuit you have earthed the sense line - is this correct?
Frank