Audio Amplifier Output Relay Delay - This is a simple circuit which I built to one of my audio amplifier projects to control speaker output relay. The purpose of this circuit is to control relay which turns on speaker output relay in audio amplifier. The idea of circuit is wait around 5 seconds after power up until speakers are switched to amplifiers __ Designed by Tomi Engdahl
Audio Amplifier Protection - Now you can protect your HiFi amplifier from damage due to excess heat. This circuit will cut off the power to the amplifier board at the moment it senses a high temperature. It automatically connects power when the temperature returns to normal. The circuit uses an NTC Thermister as heat sensor and it also has audible warning __ Designed by D Mohankumar
Audio Amplifier using BC109C - As can be seen from the circuit diagram we are really using five transistors as the BD679 and BD680 are "Darlington" pairs of transistors. The led must be a green led for correct operation. (The voltage across a green led is higher than the voltage across a red led.) When using a 12v supply the voltage at T1 collector should be (about) 5v and at T2 base (about) 7v. This amplifier will be unstable (it will oscillate) without the 4k7 variable resistor connected to the input. __ Designed by © David Hoult
Audio Amplifier: 14w - single supply and split supply versions of the popular tda2030 amplifier __ Contact: P. Townshend EduTek Ltd
Audio Amplifier: 32w - single supply and split supply versions of the popular tda2050 amplifier __ Contact: P. Townshend EduTek Ltd
Audio Amplifier: 7w - a simple circuit based around lm383not tested __ Contact: P. Townshend EduTek Ltd
Audio Amplifier: Bridged 20W 12v - a common amplifier based around the tda2005 ic. __ Contact: P. Townshend EduTek Ltd
Audio Amplifier: Guitar Fuzz - a classic design based around an op-ampnot tested __ Contact: P. Townshend EduTek Ltd
Audio Amplifier: Pre-Amp - a low signal pre-amp using an op-amp from a single battery supply __ Contact: P. Townshend EduTek Ltd
Audio Amplifier-22 Watt - The 22 watt amp uses a TDA1554 two channel Audio Amp chip and is easy to build, and very inexpensive. The circuit can be used as a booster in a car audio system, an amp for satellite speakers in a surround sound or home theater system, or as an amp for computer speakers __ Designed by Aaron Cake
Audio Amplifier-LA4440 - Application: Make your own computer speaker system. This simple and inexpensive project will let you set up a small audio amplifier and let more sound out your computer. Description: A simple audio amplifier based on the LA4440 IC. This will take your computer’s headphone level output and amplify it to drive a pair of __ Designed by Popescu Marian
Audio Amplifier-LM317 - You probably know that LM317 IC is used as an adjustable voltage regulator, but did you know it can be used as an audio amplifier? This is a class A audio amplifier built with LM317 that delivers a maximum 1W audio power. Use a good heatsink for the LM317 IC and adjust the 5K variable resistor so that you have 4.5V on __ Designed by Popescu Marian
Audio Amplifiers-TDA2005 - TDA2005 is a class B dual audio power amplifier specifically designed for car radio applications. Its high current capability (up to 3.5 A) and the ability to drive very low impedance loads (down to 1.6 ohms) makes this circuit a good choice for cheap power booster amplifiers. TDA2005 stereo amplifier 2 x 10W TDA2005 20W __ Designed by Popescu Marian
Audio Amplifiers-TDA2030 - TDA2030 is a monolithic integrated circuit in Pentawatt package, intended for use as a low frequency class AB amplifier. It provides 14W output power (d = 0.5%) at 14V/4Ω at ± 14V or 28V, the guaranteed output power is 12W on a 4Ω load or 8W on a 8Ω TDA2030 10W audio amplifier circuit TDA 2030 audio amplifier __ Designed by Popescu Marian
Audio Attenuator Features 0.001% TH - 07/18/96 EDN-Design Ideas A single-channel audio attenuator package maintains input-signal fidelity as it attenuates the signal level in 1-dB selectable steps over 0 to -62 dB. National Semiconductor's LM1971, with 3-dB bandwidth of more than 200 kHz, is a digitally controlled device that also includes a >100-dB mute function. Applications include communications systems, cellular phones and pagers, and audio-mixing systems. Design by Bill Schweber, National Semiconductor Corp, Santa Clara, CA
Audio Bargraph Display - An easy to use LED bargraph display to monitor audio levels. Circuit monitors a single channel, so build two for stereo. __ Designed by Andy Collison
Audio Buffer & De-Emphasis - Use this circuit after a repeater receiver to de-emphasize the audio going to your controller. __ Designed by Lou Harris N1UEC offsite link
Audio Compander - This audio compander circuit schematic is equipped with NE575 produced by Signetics, it is working with a 3 – 7V battery and has a current consumption of 3.5mA at 3V and 5mA at 7V. The companding process (input compression, output as expander) is improving the signal/noise ratio on a communication line. NE575 contains 2 __ Designed by Popescu Marian
Audio Detector - Someone asked, a couple weeks ago, for a circuit to do audio detection.
This is what I used. Here is one that uses a single IC (LM324 quad op amp)
and a handful of parts. This circuit is for detecting one of those 3.6khz
(approx) beepers from Radio Shack. __ Larry Barello
Audio effects: guitar phaser - This circuit is a phaser circuit, as used in guitar foot-pedal effects. It used 11 sections of op-amp such as LM324 but others will do. The whole circuit works of a dual rail supply: +/- 9v. The 0v rail is indicated by a chassis sign. Make sure these supplies are well decoupled. There is a spare section of one of the IC's which you could used to derive a center tap from an 18v supply. __ Designed by Richard Torrens
Audio equalizer features transimpedance Q enhancement topology - 6-Mar-08 EDN-Design Ideas A novel op-amp configuration enables a graphic equalizer with a minimal number of amplifiers Design by Herminio Martínez, Encarna García, and Eva Vidal, Technical University of Catalonia, Barcelona, Spain
Audio Equalizer for Communications Use 234 kB PDF file - This five-band audio equalizer was originally designed for use at a multi receiver site (a voting system hub). Originally published in the May 1990 QST __ Designed by Robin Humbolt WA4TEM
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