Audio-Powered Tape Recorder Controller
A tape recorder can be controlled by rectifying the audio input and driving an IRF511 power MOSFET t...
Satellite Tv Audio Switcher
Some channels offer a separate audio mode (SAP) in a second language. It is usually transmitted on 6.8 MHz, whi...
Precision Narrow-Band Tone Switch
This signal tracker and lock detector combine to make a precision tone switch. Filter R3/R4/C2 determines...
Microphone-Controlled Voice-Activated Switch
An electret microphone feeds a bandpass filter circuit (IC1A), then feeds a comparator, which ...
Sound-Activated Switch
This circuit provides either latched switching or timed switching. U1A and UlB provide audio amplification from the ...
Single-Chip Chime
This circuit uses only one IC, produces a pleasant tone, and sports a single control for adjusting the tone"s chiming rat...
Electronic Music Maker
This electronic music maker uses an astable oscillator circuit that is controlled by a photocell. The light falling ...
Electronic Bagpipe
The electronic bagpipe mimics the sound of real instruments. This circuit uses two UJT oscillators and an amplifier (Q3,...
6W Warble-Tone Siren
This circuit uses a CMOS chip and a VMOS FET amplifier for 6 W of audio output. 18 W of audio can be generated using ...
Beat-Frequency Audio Generator
Ql is a fixed oscillator operating at 455 kHz. Ul is a mixer, with its own internal oscillator running at 45...
Simple Audio Clipper/Limiter
For use with headphones, this circuit sets the audio clipping level via a 5-KOhmhm pot. This type of noise cli...
Audio Shunt Noise Limiter
Examples of RF and audio ANL circuits. Positive and negative clipping occurs in both circuits. The circuit at A i...
Simple Utility Mixer
Here"s an interesting mixer circuit. With it you can effectively combine signals from audio to high-fre-quency RF. Als...
Audio Mixer
Three audio circuits are combined in the circuit shown. Each input is coupled to its own level potentiometer (Rl, R2, or R3) an...
4-Channel Mixer
The proposed mixer is designed around four current-driven transconductance amplifiers contained in an SSM2024 from Precisio...
Stereo Mixer With Pan Controls
This stereo mixer has two mono mixers and a modification to the microphone inputs. When a microphone is in u...
Dynamic Audio Mixer
The dynamic mixer combines two audio inputs by adding the primary signal, Input A, to a gain-controlled signal, Input B...
Acoustic Sound Receiver
The receiver is an audio amplifier fed by SPKR1, a piezo speaker that is used as a microphone. A scope or headphone...
Acoustic Sound Transmitter
Pulsed sound is produced by this circuit. Ul is used as a bistable multivibrator, which acts as a contact "debou...
Audio Filter Analyzer
When this circuit is connected to a filter and an oscilloscope, the scope displays the filter"s frequency response. A...