#Vehicle air conditioner control panel driver#

#Vehicle air conditioner control panel driver#

I suppose the rheostat is a big clunky thing that is simply in series with the fan motor - I don't see any problem replacing that with PWM as long as you use a beefy enough driver circuit with the proper EMF protection. I greatly appreciate thoughts and alternate suggestions. The blower speed would be constant based on PWM or Pot setting. Depending on the delta between set temp and the actual temp, a relay would be activated which engages (then disengages, when appropriate) the compressor. This provides 12v to the PWM for the blower if I don't use a rotary pot, and powers up the digital temp controller (arduino-based?). I envision it working like this (car already running and supplying 12V power) Am I correct in this train of thought, or should I be heading in a different direction?

My basic thought is that I can use a PWM or maybe a rotary pot (both + and - directions) to control the blower, and maybe two buttons or a rocker to control the cut-in/cut-out temp for the compressor, and of course a power on/off switch for the controller and system. In the cabin are two knobs, one is attached to a rheostat/potentiometer which gives variable fan speed (not 0-1-2-3 as in normal cars, but rather 'Off-100%-~10%') and a second knob which controls the pulley/clutch to engage the compressor, via a thermocouple and mechanical switch. The current A/C is composed of a blower (12V, squirrel cage fan with 7A motor) and obviously the compressor and its pulley/clutch. The heater is totally separate from the A/C. The car is a 1971 Mercedes Benz 280SE, and the A/C is basically an under-dash add-on. Unlike the original poster, my car's air conditioning system is vintage and very rudimentary. I, too, would like to control my car's airconditionng with a digital controller. I have fairly decent electrical skills, better mechanical skills, can follow plans and diagrams. I was searching for this topic, and thought I would revive this thread vs start a new one. New here and new to this world of Arduino.

The last two things are definitely possible. From the point of view of the Arduino I don't suppose it matters much - as long as it is clear in your own mind what the controls do and what algorithm you want to use to control them, and you have suitable actuators installed to operate the controls, all that's left is to make/buy the driver circuits for the Arduino to drive your actuators, and program the Arduino to implement your control algorithm. Is your 'temperature control' just something that varies the speed of a fan? I thought this might be something that either moves a flap to mix heated/unheated air, or engages an aircon pump. I guess you would dismantle the existing dashboard controls and reconnect whatever cables etc they operate to some control box that you would construct, which would contain heavy duty rotary and/or linear actuators.įrom your description it seems unclear what the two controls are. I think the most difficult part of this project would be making an actuator for each control that can generate enough force to move the control and position it accurately. In my experience, things like car heater controls and switches tend to need quite high forces to operate.