12 to 48 Volt DC Variable PSU

[bryan1]

G'day Guy's,
Well that 12-48 volt 300 watt cnc spindle finally turned up off fleabay so now I need to make a circuit to power the thing. At the moment I just use my dremmel on my cnc which after close to 5 years is finally going.

Being so busy with work I haven't yet done a research on the forum as it may of already been done before.

Now for powering I do have a decent transformer that outputs 95 volts ( old telstra phone transformer) and i have used that for powering an AC heating element with no problems. It may pay for me to scroungemad: BUY) a new transformer too.

Anyway tonight after work I'll get a bit more research done.

Regards Bryan

Note: Yes I could just buy a fleabay based psu but the track record of those are patchy at best.

 

[alec_t]

Going from 95V to 18-48V at 300W won't be trivial. Easier (possibly cheaper) to buy a suitable power supply?

 

[bryan1]

Hi Alec,
I ended up replacing the switch on my 75 volt 10 amp variable psu I build years ago to power my watch makers lathe and it works great on the cnc spindle, that psu has a 22,000uf cap the size of a coke can and a variable resistor about 4" diameter. Hopefully that psu will have enough grunt with some overhead for long term use.

Regards Bryan