Thanks for your valuable suggestions.
1. Further, could you please suggest any AC to DC step down IC, if exists. Is there any very light weight (IC instead of bulky transformers) option for stepping down mains AC to DC (unregulated), which could then be fed to next stage IC to get desired regulated DC ?
I'm sure that, such IC or circuits do exist, as I've seen a very light weight (less than 100gm), SMPS which had a mechanical switch to get different regulated DC outputs.
2. Any IC which could control both output DC current and and regulated voltage via micro-controller, thus providing programmable regulated DC voltage and current ?
3. Regarding the PICAXE, I've the hardware/software to program PIC's and AVR's using C. The main problem for me is to find the hardware (IC's etc.) for my programmable power supply.
thanks