Traditional design of acoustic-electrical conversion circuit

/Article/dz/dzzz/2006 1 1/ 13 12 . html

Second, the circuit principle:

1.D2~D5 ~ D5 form a bridge circuit. When the output of U 1D is low, the SCR is not conductive, and the no-current path of the lamp is not bright. Only when the output of U 1D is high level and SCR 1 is on, the light will light up.

2. The voltage stabilizing diode voltage stabilizing circuit composed of D2 ~ D5, R7, DW and C3 generates 7.5V DC voltage to supply power to the control circuit.

3. The control circuit is composed of transistor 90 13 and four NAND gates CD40 1 1 of COMS circuit. Acousto-electrical converter MIC converts sound into electrical signal, and photosensitive resistor MG45 is controlled by light to change its resistance (light intensity resistance becomes smaller). C2 and R5 form an illumination delay circuit with time constant = =R5×C2.

Please analyze the specific process of control by yourself.

Third, the circuit installation matters needing attention:

The circuit board is connected with 220 volts high voltage. When connecting 220 AC, you must connect the light bulb (220V, 25W is enough). And pay special attention to prevent electric shock.