Circuit knowledge

Wednesday, September 3, 2014

Simple Knight Rider lights Circuit for model cars

This simple schema drives 6 LEDs in Knight Rider scanner mode. Power consumption depends mainly on the type of LEDs used if you use a 7555 (555 CMOS version).

Simple Knight Rider lights Circuit Diagram

Note
That V_DD and GND for the ICs are not shown in the schema drawing.

Pin-outs:
(7)555		4017
1	GND	1	Q5	9	Q8
2	TRIGGER	2	Q1	10	Q4
3	OUTPUT	3	Q0	11	Q9
4	RESET	4	Q2	12	CO
5	CONTROL VOLTAGE	5	Q6	13	NOT ENABLE
6	THRESHOLD	6	Q7	14	CLK
7	DISCHARGE	7	Q3	15	RESET
8	V_DD	8	GND	16	V_DD

Nite Rider Lights

As a keen cyclist I am always looking for ways to be seen at night. I wanted something that was a novelty and would catch the motorists eye. So looking around at my fellow cyclists rear lights, I came up with the idea of NITE-RIDER. NINE extra bright LEDs running from left to right and right to left continuously. It could be constructed with red LEDs for use on the rear of the bike or white LEDs for an extra eye catcher on the front of the bike.All ICs are CMOS devices so that a 9V PP3 battery can be used, and the current drawn is very low so that it will last as long as possible.

Parts

1 555 timer IC4.
1 4027 flip flop IC1.
2 4017 Decade Counter IC2 and IC3.
3 4071 OR gate IC5, IC6 and IC7.
1 470 Ohm resistor 1/4 watt R3.
2 10K resistors 1/4 watt R1 and R2.
1 6.8UF Capasitor 16V C1.
9 Super brght LEDs 1 to 9.
1 9V PP3 Battery.
1 single pole switch SW1.
1 Box.

How The Circuit Works.

IC4, C1, R1 and R2 are used for the clock pulse which is fed to both the counters IC2 and IC3 Pin 14.
IC1 is a Flip Flop and is used as a switch to enable ether IC2 or IC3 at pin 13.
IC7a detects when ether IC2 or IC3 has reached Q9 of the counter pin 11.
IC5, IC6 and IC7a protects the outputs of the counters IC2 and IC3 using OR gates which is then fed to the Anodes of the
LEDs 1 to 9.

Car Head Lights Turn Off Wiring diagram Schematic

This schema when setup in a car automatically turns off the head light after a preset time after the ignition switch is turned off.So you can walk out easily from the dark garage in the light of your car.

Circuit diagram :

Car Head Lights Turn Off Circuit Diagram

When the ignition switched on first the voltage from battery is fed to the relay through diode D1.When the ignition switch is turned off it produces a negative going pulse at the pin 2 that triggers the timer. The output of the IC goes high for the time set by R1 .This makes the transistor Q1 to conduct to energize the relay to drive the headlight.After the set time the light goes off.With the value of components used you can make a setting from 10 S to 60 S.

Notes :

Assemble the schema on a good quality PCB or common board.
Fit the potentiometer on somewhere on the dashboard so that you can easily set the timing.