These are a few simple LED circuits. They can be used as warning lights - as fake motorcycle alarms - as a doorbell substitutes for the deaf or hearing impaired.
Fake Alarm - Circuit No.1
Detailed Circuit Description
Flashing LEDs can be used to create the impression that an alarm has been fitted. Or they can be used in conjunction with a real alarm - to warn-off a potential thief. If you replace R1 with a 4M7 pot - you can control the rate at which the LEDs will flash. The slowest rate is about one flash per second. If you'd like a slower rate - increase the value of C1.
I've used this first circuit on several motorcycles. I mounted the LEDs inside the lights. They were pushed through small holes drilled in the plastic reflectors. I put the control circuit behind the reflector in the tail light.
The small number of components means that the circuit can be built without a circuit board. The parts can be soldered directly onto the pins of the IC. Roll the whole thing carefully in a little BluTack - and cover the outside with several layers of electrical tape. You should end up with a small cylinder - that's well insulated and relatively impervious to moisture.
If you're installing this device on your bike or in your car - there's no need for an on/off switch. You can just leave it running all the time. However - you must fit a 1-amp (or even smaller) fuse as close as possible to your power source. This Is Very Important. The fuse is there to protect the wiring - NOT the components of the circuit. If you're mounting the LEDs inside the lights - you'll need to choose a spot that's not going to get too hot.
Fake Alarm - Circuit No.2
Detailed Circuit Description
The last circuit will flash up to two groups of 5 LEDs in tandem. This circuit will flash the two groups alternately. The alternate flashing creates the illusion of movement - and makes the display more eye-catching. Note that - although I've drawn the two groups of LEDs side by side - the individual LEDs can be mounted in any pattern you like.
A Few Examples Of Eight-LED Displays
Warning Signal - Circuit No.3
Detailed Circuit Description
This circuit is like the previous one - except that it will flash up to 15 groups of 5 LEDs per output. The LEDs will also flash at a faster rate - and they will glow at their full brilliance. Unlike the more discrete "alarm fitted" indicators - this circuit is designed to get your attention. Again - although I've drawn two groups of green LEDs side by side - the individual LEDs can be different colours - and they can be mounted in any pattern you like.
TURN ON THE FLASH