the circuit of the double hresholds temperature alertor(2)

Published:2011/6/20 6:36:00 Author:Ariel Wang | Keyword: double hresholds, temperature , alertor | From:SeekIC

The 220V AC voltage is reduced by T,commutated by UR,filtered by C3 and regulated by IC2.It provides +6V voltage for amplifier circuit of temperature detect ,ultra-low frequency oscillator and sound warning circuit.When the controlled temperature is beyond the upper limit of the set temperature,the resistence of RT is decreased.N2 outputs low level as the reference voltage of non-inverting termina is lower than it of inverting termina .VD2 is stopped.The ultra-low frequency oscillator consists of N1,R5,R7～RiO and C3.VL2 is lighted.At the same time,super low frequency oscillation signal modulates the audiofrequency oscillator which consists of R14～R16,C3 ,VI and V2.The driver BL gives out buzz sound every now and then.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Automotive_Circuit/the_circuit_of_the_double_hresholds_temperature_alertor2.html

Print this Page | Comments | Reading(3)