DIY Electronic kit speaker circuit hearing aid analog circuit experiment soldering project practical component welding teaching

1.Description:

Hearing aid is also called deafness hearing hearing is composed of microphone  front low amplifier power amplifier circuit and other parts，this kit combines the circuit and the actual situation design and production. Is the ideal training kit for learning analog circuit.

2.Working principle

1>.The electret microphone BM serves as a transducer, which can convert sound signals into corresponding electrical signals and amplify them through the male capacitor C1 to the preamplifier. R1 is the bias resistor of the electret microphone BM, which provides a bias voltage for normal operation of the microphone.

2>.VT1, R2, R3, and other components form a front-end low-frequency amplification circuit, which preamplifiers the audio signal obtained through C1 male integration, and amplifies it. The audio signal of the rear is added to the potentiometer RP through R4 and C2, and the potentiometer RP is used to adjust the volume. Success rate of VT2 and VT3 groups. The amplification circuit amplifies the audio signal to power and drives the earphones to work through the earphone jack.

3.Parameter:

1>.Work Voltage: DC 3V

2>.Work Temperature:-25℃~85℃

3>.Work Humidity:5%~95%RH

4>.Size: 39*25mm