Temperature warning indicator circuit
The circuit is a low temperature regulator, supervisor, warns us about global warming. Temperature control is done by the thermistor TH1, which is a negative factor. The resistance varies between 10KO at 25 ° C and about 1KO at 94 ° C. The trimmer TR1 regulate the exact temperature at which the Q1-2, connected as a Darlington, lead me, making the relay K1 to close and IZ, sound. The alarm is activated when the temperature is greater than the default. The thermistor should be located away from the rest of the circuit, so as not to risk from the heat. The power circuit is battery 9V, but if it is mounted in a fixed position, then we can supply with a constant voltage power supply. The relay contacts can be connected load which we, as a bulb, another circuit, etc. It can also add an LED, if we are to sign and visual stimulation. The adjustment is done by immersing the thermistor TH1, in the water which we know the temperature (contacts should be well insulated so we do not have s...