Hello readers! In this Instructable, I am going to be detailing how to make your very own pulsating LED, just like the light on the top of the TARDIS! I am going to do my very best to explain this process, and why certain aspects of this circuit are designed in that particular way, as well as hopefully providing you with the knowledge that enables you to alter certain things in this build to match your liking. The inspiration for this project came when designing a clock face for my Resistant Materials GCSE. I wanted to make my clock look like a TARDIS, however, didn't want it to compose of just boring plastic. So, I decided to replace the top of my acrylic TARDIS with a pulsating LED. I then designed a circuit that could perform that very task (see the diagram above). So, without any further ado, let's get straight into it!
Before proceeding, I would like to just quickly recommend that you pay careful attention to the illustrative pictures provided on each step! They have detailed notes and will definitely help you with building and understanding this circuit!
Step 1: Gather All The Parts!
OK, so let's start by gathering all the parts we are going to need. You should be able to pick these up on the cheap from your local big electronics store (US: RadioShack UK: Maplin Online: farnell.com)
For this build, you will need:
- Veroboard (Stripboard) (about a 12cm x 12cm area will suffice)
- A switch
- 5 x 330Ω resistors
- 3 x 10kΩ resistors
- An 8-pin IC holder
- A 555-Timer chip
- A 100uF (microFarad) capacitor
- An LED (of any colour)
- A BC108 transistor
- A 9 volt battery
- A 9 volt battery clip
- Wire (and plenty of it: red and black)
- Heat-shrink tubing of different diameters
- Squares of Velcro (optional - for finishing touches)