variable DC DC converter

[dmta]

Hi all,

I want to make a variable DC DC converter using lm2678. The output voltage and maximum current should be adjusted using digital methods (no pots). I have thought of the following circuit. I cannot yet implement it as the inductor will take some time to arrive.

Will this work? Do you have any other good designs ?

Regards

 

[alec_t]

I cannot yet implement it as the inductor will take some time to arrive.

In the meantime you could perhaps simulate it to test the design principles?

 

[jpanhalt]

I used that regulator to make a variable DC supply with a pot for the FB voltage. I did not include current control. I agree that while you are waiting for your inductor, you could test and/or simulate the part of your circuit that generates the control voltages.

John

 

[dr pepper]

A digital pot or resistor string d to a would give you remote control, kinda gets complicated though if you want isolation, maybe an 8 pin micrcontroller controlling the pot/reg communicating to the o/p side via serial through an opto isolator.
Current limit is a little tricky to achieve without noise.
I too have used the lm2600 series, veritable ic's.
If you google elektor switching bench supply you'll find an interesting article for a bench supply using this ic, it has voltage and current control and has a microcontroller interface.