Lambda Probe Readout For Carburettor Tuning
A lambda probe (or oxygen sensor) can be found on the exhaust system of most cars running on unleaded fuel. Having reached its normal operating temperature (of ...
Car Interior Lights Delay
Most cars do not have delayed interior lights. The circuit presented can put this right. It switches the interior lights of a car on and off gradually. This mak...
Car Boot Lamp Warning (ICM7556)
On many cars, the boot light will not go out until the lid is properly closed. It is all too easy when unloading the car, to leave the lid ajar. If you are unlu...
Up/Down Timer For A Power Antenna
This up/down timer was designed to control a power antenna on a late-model vehicle. Normally, this vehicle uses a body computer to control the antenna. However,...
Speed-Limit Alert
IC1 forms a differential amplifier for the electromagnetic pulses generated by the engine sparking-plugs, picked-up by sensor coil L1. IC2A further amplifies th...
battery isolator
This circuit is even simpler and employs a 6V feed from one of the stator connections on the vehicle`s alternator. This is connected to a 6V automotive relay (R...
reservoir pump controller
This circuit operates an automotive windscreen washer pump to fill a 20-litre drum from a 205-litre water reservoir. The drum is suspended above a drip line, wh...
rear fog lamp for vintage cars
According to current legislation in many countries, vintage cars must also be fitted with a fog lamp at the rear. In modern cars, there is a bit of circuitry as...
petrol gas switch for pajero
My current vehicle, a Pajero, was modified for dual fuel - ie, petrol and gas. However, it`s necessary to run the vehicle on petrol at regular intervals to stop...
momentary switch teamed with
This circuit allows an SPST momentary pushbutton to act as a push-on push-off switch, using a DPDT latching (bi-stable) relay. It was originally intended to all...
headlight reminder schematics
With the storm season recently upon us, it`s not uncommon to switch car headlights on during the daytime. Unfortunately, it`s easy to forget to turn them off ag...
automatic headlight reminder
Do you drive an older car without an automatic "lights-on" warning circuit If so, you`ve probably accidentally left the lights on and flattened the battery on o...
simple headlight reminders
These two headlight reminder circuits are easy to install and operate on the KISS (Keep It Simple Stupid) principle. The simple circuit involves adding just a 1...
fog lamp sensor circuit
For several years now, a rear fog lamp has been mandatory for trailers and caravans in order to improve visibility under foggy conditions. When this fog lamp is...
central locking interface
Some cheap car alarms do not have a connection for the central locking system. However, in most it should be possible to find a point in the alarm circuit which...
automatic windshield washer
Most, if not all, recent cars have an impressive amount of electronics, whether it be ABS brake systems, engine control with injection calculators, airbag activ...
synchronized multi spark
Shaping block has the role to provide fixed length impulses (2 mS) at each breaker-points opening. In this way are eliminated the false impulses which appear du...
12 volt car battery monitor
This circuit can be used to monitor the voltage level of a car battery. When the battery voltage is 11. 5V or less the transistor Q1 is on and D1 glowing. When ...
motorcycle low voltage warning
This circuit is connected to your motorcycle. It`s tapped into a circuit thats only powered with the key "ON". If you turn the bike off with the kill-switch and...
car brake light or headlight flasher
The schematic shown here can be used as a circuit for Car brake light or headlight flasher for flashing two 10 watt 12 volt lamps in car or any vehicle. .....