Amplifiers make heat when working. Too much of heat make it work bad and can die soon. This Temperature Controlled Fan Circuit for Audio Amplifiers keep amplifier cool. Fan starts only when amplifier is hot. If volume is low and less heat then fan stays OFF and saves power. The circuit is made with LM311 […]
Audio Circuits
Transistors Based Megaphone Circuit
Transistors Based Megaphone Circuit uses transistor like amplifier. Take weak sound from MIC and makes loud sound in speaker. It is used in public talk, sports, rally anywhere we need loud voice. The circuit have two TIP32 transistor in push-pull to boost sound. It work with 12V battery or 12V DC power. Circuit Working: Parts […]
Electromagnetic Telephone Ringer Circuit
Electromagnetic Telephone Ringer Circuit helps us know when call comes an when there is no need connect to phone line. This circuit is useful when there is no access or do not want to touch phone line. It works by sensing electromagnetic field from ringing signal and then buzzer turns ON. The circuit can run […]
Tone Generator Doorbell Circuit using Dual IC 555 Timers
This tutorial is about Tone Generator Doorbell Circuit using Dual IC 555 timers. This circuit is simple and works well when button is pressed. One IC works in astable mode and other in monostable mode. It is very important for making sound to run a 8Ω speaker. The circuit needs 9V DC power and makes […]
9V Battery Powered Transistor Intercom Circuit
Intercom system is device for talking at short distance. 9V Battery Powered Transistor Intercom Circuit uses 9V battery which is good for home or office talk. It uses only transistors which is easy to understand and works well. The circuit has mic and small speaker as sound. BC547 transistors make sound loud and 2N2222 transistor […]
Designing a UJT-Based Audio Tone Generator Circuit
Designing a UJT-Based Audio Tone Generator Circuit is easy and fun. It makes music sound like small instrument. It use UJT as relaxation oscillator. Push buttons change frequency with different notes. Sound goes to speaker after amplifier. Press button, tone change and w UJT 2N2646 will make right frequency. Transistor boost the sound from speaker. […]