The water boiling alarm circuit

Published:2011/7/4 19:52:00 Author:Borg | Keyword: water boiling alarm | From:SeekIC

This water boiling alarm circuit consists of 4 triodes, whose circuit is shown in the figure. In the figure, the transistors T2 and T3, resistor R2 and capacitor C,etc, compose the audio oscillator, the audio signal is output from the loudspeaker. The transistor T1, resistors R1 and W, the transistor knot be and Rt, etc, compose a switch circuit as the switch of the oscillator. Rt is the temperature sensing element, which is equal to the bias resistor of T1. Usually, Rt is reversely blocked, T1 is also blocked; when the temperature is rising up, the reversal resistance of Rt is falling down, the current leakage is rising up.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Control_Circuit/The_water_boiling_alarm_circuit.html

Print this Page | Comments | Reading(3)