Precise thermostat for 12V fan
Complex is distinguished the minimal number of components for the necessary function. Temperatures of including of fans is regulable from 0..55°C. Usage of trimers from 5K the area of includings of fans are from 0..113°C. Temperatures of exclusions is 2,5°C shorter. Hysteresis for the exclusion was able will reduce the enlargement of resistor 470K on 1,2MR. Then is the hysteresis 1°C. On the hysteresis influences the voltage power supplies 12V and this direct proportionally.
Small legs of integrated elements count from pours on right (from forward). The shown complex works already the 7 year error free (switches on the compulsory ventilation in the linear regulator power supplies and prevents the overheating).
Instead of the fan was able put the spool 12V relays (beside the added protective diode). In this way gets thermostat which switches on the exit when the temperature crosses the default. Relay was able will turn on stronger 220VAC fan.
 For the car use (the including of fan on the refrigerator) the scheme was able will become modified so that the fan can stay work and after the exclusion of contact. Then, after exclusions of fans, complex ceases spend current from the accumulator these there is no the danger from emptyings of accumulators. In principle, better puts the orginalni thermostat, but exists cases when reserve thermostats call off too often these endanger the whole engine. Then more simply place the own reliable thermostat than be in the risk that the whole machine reboil in the event of the fail off.

Warning: How the sensor LM335 has the final internal resistance with the voltage switching power supplies comes to the reduced change and on the sensor. If voltage switchings of power supplies because of includings of relays considerable has been able annul and given hysteresis. Then needs will reduce the resistor for the defining hysteresis or will stabilize current through the sensor LM335. This last easily carries out with e.g. the stabilizer of voltage LM78L05 in the circle of power supplies of sensors. Instead 4K7 needs put 1K.
Pins are counted from left on right.
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