hello fellow enthusiasts
i have built a variable power supply for myself. it works fine but it is too heavy and i move around a lot. much of the weight is because of the transformer. then i noticed all these mobile chargers they seem to do with a very small transformer. almost all commercial chargers are very light. and that too unlike my supply where the transformer is the first thing to be connected to the supply here the transformers not the first thing to be connected. Pls shed some light on this..
the bigger the transformer the more amps it can deliver
it depents what your requirements are what you need
comercialy they try to make it as cheap as posible so the transformer is designed that it just give 110% what it needs to give (sometimes not even that) if that is ok than it works
if you want something universal where you can hook up a lot of stuff than you need somthing bigger and heavier
unlike my supply where the transformer is the first thing to be connected to the supply here the transformers not the first thing to be connected. Pls shed some light on this..
They're okay for digital electronics but I'd be wary of using them to power audio or other low noise analog circuits. The switching noise and ripple can adversely affect such circuits.
(If only they'd figure out how to make aluminum transformers.)
That's what linear regulators are for, a switch mode supply feeding a linear regulator will reduce the linear supplies wasted power to it's dropout voltage.
That's what linear regulators are for, a switch mode supply feeding a linear regulator will reduce the linear supplies wasted power to it's dropout voltage.
With a variable supply the switching regulator output must track the linear regulator voltage output with an offset equal to (or slightly greater than) the dropout voltage. The offset probably could be provided by a zener diode or a few normal diodes in series.
Yep, sounds like that'd work to me, might be pretty easy with an ATX supply, not sure. They have sense lines for voltage feedback from their output stage but I'm not sure how much you want to tweak a 12 volt line over 12 volts before you endanger yourself or the supplu. Ahh another project I don't have the space for =)
Thanks guys. i am planning to use it while working with cmos circuits....so dont think it needs to be a heavy duty one, being light is one of the primary conerns. so what currrent rating should i have and where can i find information and schematics for switched power supplies?