Hello There!
Now, heres my first Instructable and Ill show you, how to make a small Voltage Inverter (I mean, getting a NEGATIVE Voltage out of a POSITIVE) on you Bredboard.

Some Amplifying circuits need negative voltage to work good. This circuit schould deliver enough current to power a small OpAmp or so.

Step 1: Part List

Now, youll' need some Parts you can easily from you local electronics store.

-1x Bredboard (To mount everything on, you could even use a small Stripboard to solder everthing on)
-1x NE555 (Tiny Timer Chip, the Heart of the Circuit)
-Capacitors: -1x 25 Volt, 47 - 220µF (For Testing, Get more than One ;))
                       -1x 16 Volt (or Higher), 0.1 - 1µF (Same Here)
                       -1x 25 Volt (or Higher) 470 - 2200µF
Resistors: -3x 1.5kOhm ( 1k will work,too)
                    -1x 100kOhm (With this one you could Mess around, so you could use anything between 1k - 820k, Its up to you!)
-2x 1N4001 Diode (You can use nearly every kind of Diode, but prevent using Zener Diodes. They wont work.)
- 9V Battery or other Powersupply (If youre' using a Wallwart, make sure you put some Ripple-filter caps on the powerlines)
Finally, Some LEDs with the color of your choice.2 - 3 or so.
Does this produce AC or DC current
<p>I believe inverters produce AC voltage (DC to AC)</p>
<p>This circuit is <em>literally</em> a voltage inverter, i.e. it 'flips' some voltage above ground to some voltage below zero. An inverter of the kind you mention (which produces AC from DC) is way more complex and expensive, and a different circuit altogether.</p><p>The circuit shown here only deals with DC, does not mess at all with AC.</p>
The final product
Thanks for the awesome and useful little project I built this and it works great. Running it on a +12V power supply gets me about -10.62V. I started with it in the test phase on my breadboard and then from there made it a more permanent solution soldering it on a pcb.<br><br> I'd really like to be able to make it adjustable so I could get exactly what I needed for each project I use it for. I'm trying to find the best way to do that. If you have any suggestions, I would love to hear back from you. Thanks again!
<p>will this work for a 12V supply?</p><p>Please answer as quickly as possible.</p>
<p>yes it will</p>
<p>It was easy and I made it for my school project. I also got a first price for this. Thank you</p>
you said Bredboard
I just posted this on the arduino forum to drive LCD contrast, course its not my idea, and I would have never thought of it, but durn if you were a couple days earlier it would have saved me a boatload of googling

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