This is the LM555 Multi-Purpose Timer Development with PCB. It includes the very popular LM555 Timer IC in the 8-Pin DIP package, a well-designed PCB for the LM555, schematics, and the parts to build it. This is an extremely versatile circuit.

This Development PCB has been designed so that you may select either ASTABLE or MONOSTABLE modes of operation by simply populating the PCB with appropriate components. Astable is "free-running" and can be used as a continuous pulse generator. Monostable is a "one-shot" and can be used for outputting one pulse at a time.

The Trigger, pin 2, is also available as two separate inputs, one configured as a "Normally-Open" and the other as a "Normally-Closed". Just populate the ones you need. The circuit also has the Reset pin available as an input or it can be connected to the Power Supply via a resistor. You get to select which one you want.

Plus, we have included some pretty neat outputs. Pin 3, which is the output, is set up for 4 different outputs which can be populated as needed. One output is a string of three LEDS in series with a resistor tied to VCC (Power). You can power White LEDs with this. The second output is with two LEDs that can alternately flash on and off to indicate what state the output is in. The third configuration has pin 3 driving the Base/Gate of a Transistor/FET (TO-220 or TO-92) with open collector/drain outputs. This lets you drive much higher loads and at higher voltages than what the PCB is using for power.

There is a reverse-biased Diode across the Collector/Drain output for inductive kickback suppression. There are two outputs associated with just this Transistor/FET circuit. There is a Jumper that will allow you to select VCC as the power source or you can put in a different voltage, higher or lower. The fourth option is for pin 3 to go directly to OUT-1 via jumpers.

This circuit is truly amazing with all the available options. Use it in prototyping your designs or even as a stand-alone module for your projects. Along with the PCB, you also get a selection of Transistors, Resistors, Capacitors, LEDS, and Diodes to experiment with. The PCB is 1.60" long x 2.50" wide made of .062" FR-4 epoxy glass. All holes are plated-through. The traces are wide to withstand numerous circuit changes and it has 4 mounting holes.

This kit does not include the tools you will need to assemble the circuit. You will need tools such as a soldering iron, solder, wire cutters, etc.