DC-DC step up converter?

[markusA]

Is there an easy way of stepping up your DC voltage?

 

[richie00boy]

You can multiply it by whole numbers, e.g. 2x, 3x, 4x etc but only at currents of a few mA. Using a 555 timer.

 

[Sch3mat1c]

Yes, hundreds of methods.

Could you give a specific purpose, i.e. input and output voltage and current ranges, efficiency, ripple, etc.?

Tim

 

[wwenze]

eBay is one easy method.

 

[tomchr]

Look up "boost converter" or "buck/boost converter". A boost converter can be as simple as a 555 timer IC, MOSFET switch, inductor, diode, and output cap. Feedback is preferred, though.

Rather than building your own converter, you could also use one of the many available ICs. Look in the Power section of National Semiconductors, Texas Instruments, and others.

Above assumes that you're talking relatively low voltages (< 40 V).

 

[wakibaki]

Circuit - +5v Powered Charge Pump Battery Charger - Circuits designed by David A. Johnson, P.E.

Voltage doubler, only good for ~70mA

w

 

[markusA]

It's a small power supply, 21-24VDC @ 100mA.
I wan't to use stuff that I have lying around instead of spending money on a new wall wart.

Input voltage? I guess anything between 5-18VDC? There are lot's of wall wart lying around.
None big enough to do it on it's own though. :/

Linear operation is good, switch mode supplies tend to deteriorate the audio signal in the end. It's for a Lightspeed clone.

 

[richie00boy]

Not possible without going the switching route. If you had AC wall warts at least you could halfwave voltage double then regulate.

 

[markusA]

That's what I was afraid of.
It's no problem anyway, I found a suitable 24VAC wall wart.
A regular psu should pose no problem and I found allmost all the parts I need in the parts bin.
Maybe I'll find the rest as well if I look again.

 

[Sch3mat1c]

[IMGDEAD]http://myweb.msoe.edu/williamstm/Images/Discrete_Boost.png[/IMGDEAD]

Noise, who needs it. A big chunky cap on the output (220uF as shown, plus 10uF tantalum, would be plenty) keeps ripple down, and an LC filter will keep RFI away.

Tim