Help with Touch Alarm Circuit

kindly help me explain on its circuit flow...plssss
https://electroschematics.com/6129/touch-alarm/

It explains how it works. What don't you understand?

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plss...help meabout the circuit flow..plsss
https://electroschematics.com/6129/touch-alarm/

i need more precise explainition

A single post would have been adequate. Since it is your explanation add more words. It is a simple circuit and there is little you can say about it. If you understand the basics you should know how it works, if not start with learning some transistor theory.

Ron

Please limit this to the other thread you started. Multiple threads will confuse people.

Ron


Merged: Moderation.E

T1 and T2 form a darlington pair switch which needs a very low input current to turn on.
T1 is turned on when your conductive finger touches the touch plates.
When T1 turns on then it turns on T2 and makes its emitter a logic high voltage.
R1 and R2 bias T3 on which oscillates with T4 with positive feedback applied by C2 and R3.
T4 drives the speaker.
When T2 turns on it charges C1 which keeps the bias on T3 through R2 so the oscillations continue for a second or two after you remove your finger from the touch plates. R4 discharges C1 after a second or two to stop the oscillation.