29-06-2012, 05:43 PM
ANTI-COLLISION REAR LIGHT
[attachment=26198]
During poor visibility, i.e.,
when there is fog, or at dawn
or dusk, or when your vehicle
gets stalled on a lonely stretch of
a highway, this flashing light will provide
safety and attract the attention of
people to help you out. It uses highbrightness
yellow LEDs.
The circuit uses a dual binary
counter CD4520, quadruple 2-input
shift-and-store bus register CD4094
and some descrete components.
An oscillator is built around gate A,
whose frequency can be varied through
preset VR1 when required. The output
of the oscillator is fed to IC1 and IC3.
When the circuit is switched on, the
oscillator starts oscillating, the counter
starts counting through IC1 and the
data is shifted on positive-going clock
through IC3. As a result, the four groups
of LEDs flash one by one.
All the LEDs will then glow for
some time and switch off for some
time, and the cycle will repeat. Input
pins 12 and 13 of the unused gate D
must be tied to ground and pin 11 left
open. Preset VR1 should be of cermet
type and used to change the flashing
rate of each group of LEDs.
The circuit works off regulated
12V. Assemble it on a general-purpose
PCB and house suitably.
[attachment=26198]
During poor visibility, i.e.,
when there is fog, or at dawn
or dusk, or when your vehicle
gets stalled on a lonely stretch of
a highway, this flashing light will provide
safety and attract the attention of
people to help you out. It uses highbrightness
yellow LEDs.
The circuit uses a dual binary
counter CD4520, quadruple 2-input
shift-and-store bus register CD4094
and some descrete components.
An oscillator is built around gate A,
whose frequency can be varied through
preset VR1 when required. The output
of the oscillator is fed to IC1 and IC3.
When the circuit is switched on, the
oscillator starts oscillating, the counter
starts counting through IC1 and the
data is shifted on positive-going clock
through IC3. As a result, the four groups
of LEDs flash one by one.
All the LEDs will then glow for
some time and switch off for some
time, and the cycle will repeat. Input
pins 12 and 13 of the unused gate D
must be tied to ground and pin 11 left
open. Preset VR1 should be of cermet
type and used to change the flashing
rate of each group of LEDs.
The circuit works off regulated
12V. Assemble it on a general-purpose
PCB and house suitably.