This is Electronic Stethoscope circuits. Usually the stethoscope is a medical device that listens to the heartbeat. Which we can make it with the least amount of electronic equipment so easy to make.
Do you love music? Imagine we can build power amplifiers system. Sound good, doesn’t it? Here are many circuits. For example, about Audio amplifiers, bridge amplifier, Using transistor or IC or MOSFET, Mixer, Graphic Equalizer, Preamplifiers. And, Sound generators, tone controls, Melodies, Sirens, Animal sound, effect voices. Even, Burglar alarm, and more. I cannot explain to you all. But sure I do not like to see you miss them.
Today I would like to introduce the simple and economical simple siren circuits. It is suitable for beginners. My son will gradually build this circuit onto the PCB layout. Look at below! 4 Circuits.
This is low noise tone control circuit using 4558 or NE55532, easy make with one PCB layout board, can adjust bass treble mid volume,also use to microphone.
Here is five burglar alarm circuits for you can look as idea To protect their property from thieves. simple switching, vibration systems, touch-sensitive.
See Intercom circuit using LM386 and other IC. louder transistor version. And easy and cheap. With Condenser MIC and Speaker, longer cable.
This is Simple Solar light alarm circuit with the special edition, that improve this circuit whole new to higher efficiency. use solar cell instead of LDR
The Mouse and Rat repellent circuit using astable multivibrator which use sound waves or ultrasonic so it escaped away. Use transistor and piezoelectric.