This project is designed as an introduction to soldering, identifying common
components, using the resistor colour code
and placing components correctly on stripboard. The LED flashes at about 3Hz (3 flashes per second).
This project uses a 555 astable circuit.
resistors: 470, 1k, 220k
capacitor: 1µF 16V radial
red LED (or orange, yellow or green if you prefer!)
555 timer chip (IC)
8-pin chip holder (a 'DIL socket') for the 555 chip
battery clip for 9V PP3
stripboard: 6 rows × 21 holes
Solder the 8-pin chip holder in the correct place on the stripboard.
Break the 4 tracks under the chip holder with a track cutter tool.
You can allow extra holes if your piece of stripboard is large enough.
Use the resistor colour code to
identify the resistors which are marked with coloured bands to show their value.
Insert and solder the resistors in the correct position, they can be put in either
way round, but you must line them up correctly with the chip holder.
Identify the other parts, then solder them in the correct position and the
right way round. To help you identify the parts please see our page on
Solder the 2 wire links in place around the chip holder, it is easier to use
plastic-coated single-core wire. (The flexibility of stranded wire is not needed for
connections like this and the strands can be difficult to push through the small hole).
Finally insert the 555 timer chip and connect a battery!
For a circuit diagram of the 555 astable circuit used in this project please see the
A kit for this project is available from
If you are new to electronics buying a kit is a good way to be sure you have the correct parts for the project.