Hello Good People

I have a car door lock actuator (central locking) that uses 12V to energise. I only have 24V available. What would be the best way to switch the 24V to energise the 12V actuator ?

(PS. I have tried to build a circuit which uses a relay (24V coil) and then in turn reverses the polarity of the 12V supply from + to - and vice versa. Problem is my 12V supply, I use a 7812 +12V DC Regulator from the 24V to supply the actuator. Look like the current drawn by the actuator is around 3 AMPS!. The Regulator gets VERY HOT.

Any help or ideas appreciated.

Thanks Rudie

rudielamps: Hello Good People

I have a car door lock actuator (central locking) that uses 12V to energise. I only have 24V available. What would be the best way to switch the 24V to energise the 12V actuator ?

(PS. I have tried to build a circuit which uses a relay (24V coil) and then in turn reverses the polarity of the 12V supply from + to - and vice versa. Problem is my 12V supply, I use a 7812 +12V DC Regulator from the 24V to supply the actuator. Look like the current drawn by the actuator is around 3 AMPS!. The Regulator gets VERY HOT.

Any help or ideas appreciated.

Thanks Rudie

The reason for the 12 volt limit to the "actuator" is because of heat that is generated. Tell us how long you need to power the actuator and how often. If the time it is actuated is quite short and there is time for the heat to dissipate, and there are no other components being activated, then 24 volts should not be a problem.

Paul

The actuator forms part of a training system, which demonstrates the use and installation of central locking in the car. The actuator has 2 positions, one fully retracted (12V applied), and one fully expanded (-12V) supplied. So the actuator will be energized either way at all times. So basically I need to 'lock' the actuator in its position.

Originally I thought that the actuator just needs a 12V pulse, to move to its position and that's where it will stay, but however the actuator is still free to move. If I could get away with a 'pulse' then it is fine, then heat dissipated will only be for a short while and not a problem.

I was also thinking in lines of a 7812 voltage regulator / transistor combination circuit, to be able to supply more current to the actuator (without the voltage regulator getting hot).

Any further ideas ?

Thanks

Rudie

I hate to break your bubble, but central locking systems in vehicles DO NOT work that way. If they did they would QUICKLY run the battery down when the vehicle engine was not running and providing battery charging.

Paul