The hearing aid consists of a microphone, a front low amplifier, a power amplifier circuit, and headphones. This kit is an ideal training kit for learning analog circuits.

Circuit Principle
Electret microphone Bl as a transducer, it can convert the acoustic signal into the corresponding electrical signal
and through the coupling capacitor C’1 sent to the front low amplification, Rl is the electret microphone BM bias
resistor, i.e.. to the normal operation of the microphone to provide bias voltage.
VT1, R2, R3 and other components form a pre-low-frequency amplifier circuit, the audio signal coupled by Cl for
preamplification, the amplified audio signal through R4, C2 added to the potentiometer RP, the potentiometer RP
used to adjust the volume. VT2, VT3 form a power amplifier circuit, the audio signal for power amplification, and
through the headphone iack to promote the work of the headset.

Friendly Notes:
Should the item arrive damaged or with any issues, please contact us first before submitting feedback—we’ll do everything we can to resolve the problem promptly!
Please note that slight size variations within 1–2 cm may occur due to manual measurement.
Do not including battery