Buck boost converter proteus design

[muhammaduzair]

HI TO ALL.I am trying to make buck boost converter in proteus 8.I have tried but it is not working.If i change duty cycle thier is no change in output what so ever.PLz help me.HERE is the circuit diagram.
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[BradtheRad]

* Inductor current must go up and down to a measurable extent.

* Your switch is an NPN transistor. The upper end of the inductor goes negative for a time during each cycle. This may create bias current through the transistor, causing it to turn on when it is not supposed to. Therefore it may work better if you substitute a PNP.

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Or, experiment with negative bias voltages on your NPN, in order to keep it turned off at the proper times.

 

[muhammaduzair]

Now by using NPN it is still not working.

 

[muhammaduzair]

Buck boost convereter

HI.I want to make a buck boost converter but its is not working.Can anybody provide me with a working proteus model of buck boost or CUK converter.I want to make buck boost or CUK converter for MPPT solar charge controller.plz.

 

[Easy peasy]

put the xtor in the neg (bottom) there is always base current the way you have it arranged....

or use a pnp as suggested above... (with suitable level shifted drive)

 

[nimandoa]

I think this work