This is the test concentration range, is ideal for a player to a game. Without a Net Amri alarm will be heard immediately.
Operation of the circuit is to use Q1, Q2, R1, R2, R3, R4, C1 and C2 together astable multi vibrator is a rectangular waveform generator (Square Wave).
It provides approximately 3 kHz frequency by a speaker with a piano sound So come out sharp tone.
When the test loop to touch. Don copper wire. If not, tapping each of the copper wire loop tests with speakers blaring piano So do not come out.
This is Stereo Synthesiser circuit by Transistor
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