interior temperature control for cars

55 interior temperature control for cars The single most important part of any car is its driver and it stands to reason that the better the driver, the better the overall standard of road safety will be. Of course we could just leave the car to its own devices with a bit of help from a computer, but we all know what computers can do ...! No, there are some things better left undone. The alternative is to help the human driver to do a better job. This circuit is not a design to produce perfect drivers but it does aim to improve the environment in a car. Basically the circuit enables the desired temperature in the car to be set between two limits. The ambient temperature is sensed by an NTC thermistor with a nominal value of 47 k2 at 25° C. The value of the thermistor at any time is used to set the level at one of the inputs of an op-amp in the L121. This op-amp sets the triggering level of the internal logic which drives the IC output stage. Potentiometer P2 controls the second i...