Welcome doorbell and dog call alarm circuit principle

TPESD0524P is compatible with RCLAMP0524P DFN2510P10

Industrial Router Crystal 3.2*2.5mm 3225 26M (26.000MHZ) 12PF 10PPM 20PPM 30PPM

Shunluo Inductance Power Inductor SWPA Series First Class Agent

Tantalum capacitor TR3C107K010C0100 original 2011+

SMD aluminum electrolytic capacitor

The AG is a normally open reed switch. When the owner hears the doorbell, he opens the door. When the door is open, the AG is disconnected, the power supply of the latter circuit is disconnected, and the IC2 and IC3 are not powered and do not work. If it is a thief, in order to test whether there is someone in the room, they will first press the doorbell button. When the owner is not at home, during the ringing of the doorbell, VT2 turns on, causing the set trigger end of the time base circuit IC2 to turn low ( The t1 given by the graphical parameters is approximately 100 seconds. During IC2-n assertion, VT3 is saturated and VT4 is turned off, and C5 is changed from the original short-circuit state to the charged state. 1C2-b(1/2 556) and R5, C5 form a delay control circuit whose delay depends on the R5C5 charging time constant, that is, when c5 is charged, the pins 8 and 12 of Ic1-b (1/2 556) are reduced. When 1/3 Vdd, 1/2 556 is set, and 9 feet are turned to high power, so that the barking analog integrated circuit IC3 (HFC5201) is powered and gives a bark. The bark time t2 is t2=1.1R5Cs. The bark length given by the graphical parameters is about 1 minute. There are unmanned thieves in the room, and they will hear the sound of the bark.
IC3 uses a dog-sounding voice integrated circuit, which is a level, does not maintain the trigger mode, and its quiescent current is small (