voltage controller design

[renga92]

I am planning to design user controlled voltage as the output from the 55v smps which i have designed. I am planning to design it using micro controller. I want the output to vary from 10-55v in 200 steps input. Help me in giving me ideas on how to go about designing them.

thanks in advance

 

[chuckey]

You have to use a digital to analogue converter. For 200 output steps you need a 9 bit one , but as these are not available, use the next biggest one you can find (12 bit?). Now take the output from the DAC and put it through a DC amplifier to raise its level to that of the required output range (10 - 55V) and use this as the reference voltage for your SMPS. For your input to the DAC you will need 2 10 position switches with BCD output and an ordinary rotary switch, or 3 rotary switches with analogue to digital decoding.
Frank