possibly the most useful power supply

[mcquinn]

I ordered one of these today Adjustable breadboard power supply [v1.0] ID: 184 - $15.00 : Adafruit Industries, Unique & fun DIY electronics and kits will let you know how it works out.I can change the value of one of the resisters so it switches 3.7,5 or variable volts from 3.7 up to 1/2 a volt less than the input voltage "Onboard potentiometer for adjusting voltage from 1.25V up to within 0.5V of the input voltage. (20V max) '.I am planning on using it with a 9 volt wall wart so it will go up to 8 1/2 volts ,I suspect I will dial in 4 volts though."MIC2941 regulator has guaranteed 1.25A output" should be sufficient.I might finally be able to use my home made passthroughs.

[BillyBlack]

I need some more oomph.



Rechargeable Batteries & Battery Chargers - Tenergy Universal DC-DC Converter and Voltage Stablizer--Any Voltage Control, New!

[Royal]

That's the way to do it.
I had actually built something similar to this some time back, so that I could run direct off my 12 volt cigarette lighter plug in my car. I used a 3.0 amp pot and a panel mount digital volt meter. I did have to tweak it depending on the input voltage, (car running or not) But it was easily done on the fly, and could set the output voltage while under load to as little or as much as I wanted.
I did accidentally fry a couple of attys, by activating them with the pot turned all the way up. I had to make sure each time I used it that my pot was turned all the way down, then slowly dialed up till I reached my desired output.

[mcquinn]

Got my kit ,easy to build clear instructions on web site.I figure I will need to change the 3.3 volt resistor to a 13.0 K ohm to get 3.7 volts fixed so I left that resistor out until I can get the other one.Haven't hooked up usb cord to it yet to see how it vapes.I am using a 16 volt power supply I had in my junk box ,it is rated at 3 amps .