Automatic Car Windscreen Heater Timer

Pictured below is our timer for an after market car windscreen heater – in this particular example, for a Land Rover.

car windscreen heater prototype connection diagramThe biggest seller of after market heated windscreens in the UK is Ricky Evans Motorsport. (Click here for the relevant heated windscreen wiring diagram.)

The relay output from our programmable timer fits into the wiring in place of the standard on/off switch. The timer can be programmed by the driver to turn on the heated windscreen for from 1-20 minutes after the button (which can be mounted in the dash) is pressed. A panel mountable LED is provided to show when the heater is on.

Automating windscreen heating in this way prevents the heater from being left on unnecessarily long.

The exact button and LED can be substituted with whatever switchgear and indication lighting matches the vehicle in which the system is installed.

If you need one of these car windscreen heater timers, email with details of your exact requirements.

Van Lights on at Night after Alarm Activated Project

Today we worked on a project for a van owner. He has a Transit van and wanted to have the front fog lights and reversing lights turn on automatically when the alarm is activated (turned on or off) by his key fob, but only when it is dark outside. He wanted to be able to keep the lights on long enough to see when walking to and from the van in the winter.

Device to control van external lights when alarm is activated, but only when it is darkThe device we came up with is pictured above. There is a light detector (light dependent resistor – LDR) on long leads which is to be positioned in the cab of the van. When the measured light level is below a user set threshold, the controller knows it is ‘night’.

The screw in terminal at the top left of the above photograph is connected to a door servo feed wire. When the alarm is activated a high (+12V) signal is present for half a second. Our controller detects this, and if it is ‘night’ turns on the output (12V, less than 1 Amp) which is to be connected across the coil of a 40A automotive relay which switches the front fog and reversing lights. The output remains on for a user programmable duration – programmable in steps of 10 seconds, e.g. 10, 20, 30, 40..etc seconds.