555 Timer googled on the internet will turn you up about 672,000 results. Of course, each website probably has a bunch of schematics. That will turn out to be a few million results.

I've decided to post some projects about the 555 that I find are really fun and useful/ annoying. www.555-timer-circuits.com has more.

It is overwhelming about where to start...

Step 1: Gather the Parts.

You will need:
A lot of 555 timers
A lot of jumpers
A lot of electronic components

Step 2: 555 Oscillator

The 555 oscillator is just a basic way of wiring up a 555 timer to create a square or triangle wave. Some are used as LFOs or just as a free running oscillator (whatever that means.)

A 555 can be set up in monostable or astable or bistable or as a buffer...Schmitt Trigger...mode.

Monostable means that no matter how long the pulse or how many inputs, at once, it will only output once. When it is triggered again, it will pulse again but only if it has a reset.

Bistable is a flip-flop. Basically, it will remain in one position until it is reset.

An inverter flips the signal. High is low, low is high.

Step 3: 555 Blinky.

Probably my favorite because it has my name in it.

The circuit above is as follows:

C1 = 100uF
C2 = Not really needed
R1 = Potentiometer of your choice
R2 = 1Kohm resistor
LED1 (Not shown in pic) = 470ohm then LED to ground

Special Treat:
LED (Not shown in pic) = From positive to 470ohm resistor to LED

Step 4: 555 VCO

The circuit explains all.

When I built this, I used a photocell to ground to make it a light theremin. If you prefer to use a solar panel, connect the positive to positive and the negative to the CV input.

When I built this, I used, a 0.1/ 0.22 uF capacitor. I did not use the 220 ohm resistor when I built this.

None of these values are critical except I suggest that you use the 1Kohm resistor.

To add an LFO, use the second circuit. connect ground to ground and connect the output of the LFO to pin 5 of the VCO.