This project is an IR beam break detector that has a range of 10m. After publishing IR Short Distance Beam Cut Detector Giorgos Lazaridis received requests for a version that will have extended range so he build the circuit on the link below. The transmitter is based on 556 timer IC that has two 555 timers inside and an high power IR led. The receiver is based on TSOP1838 IR receiver chip, a 555 timer IC and a 4017 decade counter. Check schematics and construction details on the link below.
Long Range (10m) IR Beam Break Detector – [Link]
The Hand Steadiness Tester is a game which tests the steadiness of your hand. The player has to take the ring from one end to another end without touching it to the wire. In this the player gets 4 turns. If the player touches the wire 4 times he has to reset the game & start the whole game from the beginning.
This project consists of IC 4017, a Buzzer, a Relay, some resistors, a Push button and 4 LEDs. There is also a PCB layout given. There are many types of Hand Steadiness Testers which are very simple. This New Hand Steadiness Tester is more advanced.
Hand Steadiness Tester – [Link]
This project shows how to build a 24×6 LED matrix driven by an Arduino board. It uses 3 shift registers to control the columns and a 4017 decade counter IC with 6 transistor for scanning the rows. Check schematic and project details on the link below.
DIY 24X6 LED matrix – [Link]
Steve writes -
I am learning about electronics by building a toy laser gun. This is the sound and light effects circuitry in development. The top board has a 555 monostable timer, which turns on a bright red LED, a laser, and the sound effect. It also triggers a second board, which has 555 oscillator which is triggering a 4017 decade counter chip. That circuit is the blue LED chaser. I have it timed so that it goes one cycle during the time that the trigger from the first timer is high. Whew! a lot of work to turn on a couple of blinky lights. [via]
Homebrew laser toy blaster effects - [Link]