Introduction: The Torch Which Switches Off When Its Dark! ;) My First Useful Invention
Today I'll make my first instructable, it's about my first invention too. My 'torch' is sort of a joke invention that I made because I was bored. It is completely unuseful ;) The torch will turn on when it is light and will turn off when it is dark.
Step 1: Materials
The materials you need:
- A 100K potentiometer
- A LDR resistor
- A BC 547 transistor
- Maybe a resistor (I will later on tell why and what for resistance)
- Some wire
Step 2: The Circuit
The circuit is from:
I have changed some things, because I have used 2 AA batteries and no resistor (so the led in the torch gets more power.
Step 3: Soldering
Here is my PCB with all the components soldered on. With a - and + input from the AA batteries and a - and + output to the LED.
Step 4: Getting Everything in Place
As you see are the white wires the - and + input from the batteries, and the black and red the - and + input for the LED. The red and black wires are not allowed to touch some of the battery outputs, because then it will be a normal torch. So I glued some foam on the outputs of the batteries. I made a hole in the torch with my soldering iron (it's not the best for your soldering iron) so the wires could go in and out the torch.
Step 5: Finished!
And that's how you make a torch which wil switch of if it is dark! Totaly unnecesary! ;)
As you see some parts are exposed outside the torch. That is because my torch was to small. So feel free to make it completely look like a normal torch.