2 Tone Train Horn - With this circuit you can electronically simulate the noise of a diesel-train horn. The sound is triggered automatically as the train reaches a desired place on the track so you can produce the sound as the train approaches stations, level crossings, etc. The circuit can be built simply by using one 556 or two 555 timers __ Designed by Tony van Roon VA3AVR
2 Transistor Transmitter - A compact 2 transistor transmitter for use at VHF frequencies. __ Designed by Rob van der Weijden
2 Watt Amplifier - An audio amplifier made from discrete components with 2 Watts audio power into an 8 ohm load. Carlos has used this amplifier on his AM radio for many years. __ Designed by Carlos Feldman
2 X 22 Watt Stereo Amplifier using IC TDA 1554 - Here is the circuit diagram of a powerful and high quality stereo amplifier using IC TDA 1554. The circuit has only very few components. The circuit works best with a 4 Ohm speaker.
2 x 220W RMS Audio Amplifier - is not in English language.
2.5V to 36V Input, 12V/1A Output SEPIC Converter (Automotive 12V Regulator) - The LT3759 is a wide input range, current mode, DC/DC controller which is capable of regulating either positive or negative output voltages from a single feedback pin. It can be configured as a boost, SEPIC or inverting converter. The LT3759 drives a low side external N-channel power MOSFET. An internal LDO regulator draws __ Linear Technology/Analog Devices App Note, Sep 22, 2011
20 Watt/ Channel Stereo Power Amplifier - Based on the versatile LM1875 from National Semiconductor __ Designed by Rod Elliott ESP
200 mW Watt Stereo Amplifier - A small battery driven amplifier with 200mW output. This is a suitable amplifier for portable radios and other battery powered equipment. __ Designed by Andy Collison
200 Watt Amplifier - Circuit only, no description given
200mW LOW POWER LF AMPLIFIER - Ham RadioSchematic __ Designed by Guy Roels ON6MU
200W Audio Amplifier - Project available from Kemo Kits __ Contact: IQ Technologies
200W MOSFET Amplifier - A compact audio powerhouse ideal for guitar or PA work or for use as a general-purpose subwoofer or hifi amplifier. Many people prefer MOSFETs because of their legendary ruggedness. Altronics had a MOSFET amplifier module which produced 200W
20W Audio Amplifier using LM1875 - 20W Audio Amplifier kit is based on LM1875 IC __ Designed by Rajkumar Sharma
20W Audio Amplifier with TDA2005 - Here the 20W audio amplifier circuit which use power IC TDA2005 as the main component. The output typical is bridge output. It's mean that the speaker line is not connected to the grounded line.
20W Bridge Audio Amplifier - 20W Bridge Audio Amplifier kit, based on the TDA2005 IC, a class B dual audio amplifier, specifically designed for car radio applications etc __ Contact: IQ Technologies
20W Class-A Amplifier Module - This new 20W class-A is a refinement of our very popular 15W class-A module published in July & August 1998. It features ultra-low distortion levels, very low noise levels and a greatly simplified power supply which improves overall efficiency. Since it runs in pure class-A mode, there is no crossover distortion at all. __ SiliconChip
20W Class-A Amplifier Module; Pt.2 - In Pt.2 this month, we present the construction details for matching left and right channel mirror-image modules, together with the circuit and construction details of the power supply. __ SiliconChip
20W Class-A Amplifier Module; Pt.3 - Designed for use in our new Class-A Stereo Amplifier, this Speaker Protection & Muting Module is really a universal unit. It can be used with other SILICON CHIP amplifier modules and commercial stereo amplifiers and protects the loudspeakers in the event of a catastrophic amplifier failure. A second function of the unit is to mute the loudspeakers at switch-on & switch-off to prevent thumps. __ SiliconChip
20W T-AM - P
- This amplifier is a standard datasheet application of Tripath TA-2020-020 T-class IC. It offers 20W on 4ohm load with efficienty of up to 88%. The whole amplifier was bought as a AMP6 kit from 41hz. com. The PCB board looks really good and the copper on both sides is quite thick. The kit contains only high quality components such as 1% metal film resistors or Panasonic FC input capacitors. Because of such high efficienty the chip doesn't really require a heatsink. I used such a big one only because I had it. Before starting soldering please read the Assemble Manual so that even beginers will cope with building this amplifier. For more information you can visit the AMP 6 forum.
22 Watt Audio Amplifier - 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
implementation of the Big Muff Pi - This circuit was born with the idea of making a CMOS
workalike of the well known Electro-Harmonix Big Muff Pi (BMP). We chose the name Twenty-two Sevenths or 22/7 since it is a rational approximation of pi. The gain and frequency response of each stage were adjusted to match the corresponding stage on a BMP. The result is a rich and full sounding pedal that evokes some of the fuzz sounds circa 1969, as well as some classic singing leads. __ Contact: holler @ runoffgroove.Com
23 DB Bipolar DDS Amplifier - Some recent discussions with George Heron, N2APB and Craig Johnson, AA0ZZ regarding alternatives to using MMICs as amplifiers in DDS applications lead to the design of this 23 dB shunt feedback amplifier. This version is setup to operate at 12-13.8 volts, but with minor changes, can be made to operate with supply voltages as low as 5 volts. __ Designed by Jim Kortge, K8IQY
24 Watt Class a Amplifier - A 24 Watt Class A Amplifier made from discrete semiconductors, built and tested by Marc Klynhans from South Africa. __ Designed by Marc Klynhans
24W Amplifier using TDA1516 - Here is the circuit diagram of a simple 24W mono amplifier using IC TDA1516. The TDA1516 is an integrated class B power amplifier in a 13 pin SIL package. The IC has many useful features such as short circuit protection, load dump protection, thermal protection, reverse polarity protection etc. Here the IC is wired in BTL mode to deliver 24W of power into a 4 ohm speaker. This amplifier can be operated from a 12V DC supply and this makes it suitable for car audio applications
25 W Class a Amplifier - Musical Fidelity would let you believe that this is a Class A design. However, in common with most commercial amplifiers, it is a class AB amplifier, it simply has a rather high standing current in the output stage, which results in the first 8 watts or so being class A.
25 Watt Amplifier - This is a 25 Watt power amplifier complete with separate preamp and tone controls. In addition the circuit has a loudness control (to boost bass at low audio power) and options for super bass and super treble enhancement. This is ideal for Ipod's, MP3 or CD players or can be used as a booster amplifier. __ Designed by Julius Horfilla
25 Watt MOSFET Audio Amplifier - High Quality simple unit. No need for a Preamplifier __ Contact: Flavio Dellepiane, fladello @ tin.it
25 Watt Music Amplifier - schematic only, no description __ Contact: IQ Technologies
250mW Audio Amplifier by BC327 - Here is a very simple three transistor audio amplifier circuit that can deliver 250mW to a 8Ohm speaker. Complementary transistors BC337 and BC227 (Q3 and Q2) are used as the output pair. Transistor Q1 (BC 547) acts as the preamplifier.
25W MOSFET audio Amplifier - You can use this powerfull amplifier in any small audio project. It is very small (6.5 x 4.5 cm). It outputs 10W and uses a 9V battery.
2-9v battery-powered Amps based on the LM386. Schematic & PCB/perfboard layouts. - For better compatibility with effects driving the Little Gem, a FET buffer can be added. Both the Little Gem Mk II (seen below) and Ruby schematics include a simple buffer design. No further circuit modifications are necessary, however the input capacitor value of the amp may need to be adjusted to taste. __ Contact: holler @ runoffgroove.Com
2A3 Push-Pull Class a Stereo Amp - The input stage is comprised of a both halves of a 6SL7 octal dual hi-mu triode in a differential amp configuration with a 1ma constant current cathode load. I'm using field-effect (constant-current) diodes for simplicity. the diff amp approach was chosen for good power supply rejection, ease of balancing, good gain, and ease of application of *feedback*, if desired (hey, i like to keep an open mind). It also takes care of phase-splitting right up front. Note: I've returned the constant current diode cathode to -9V instead of ground in order to avoid the non-linearities about the pinch-off region (Vpo ~= 1.5V) __ Designed by Bob Danielak
2-channel Audio Amplifier drives stepper Motor - 12/01/06 EDN-Design Ideas Pulse-width-modulated stereo power amplifier saves components __ Circuit Design by Phill Leyva and Bill Quach, Maxim Integrated Products, Sunnyvale, CA
2-channel guitar preamplifier, Pt 1 - Each channel has bass, mid and treble controls and there's an optional digital reverberation unit as well. __ SiliconChip
2-Channel Guitar Preamplifier, Pt 2 - Add life to your music with this easy-to-build digital reverberation board. It uses two digital delay chips to give realistic effects. __ SiliconChip
2-channel Guitar Preamplifier, Pt 3 - Pt.3: Building the preamps and reverb module into a metal rack case __ SiliconChip
2m-20m Transverter - This little circuit is a transmitting and receiving converter (transverter) that converts a FT290 or similar multimode handheld transceiver to the 14MHz amateur band. The project is a single board module that needs an external local oscillator, for example, the VHF harmonic oscillator (or QRP VHF FM TX) LO for transverter project. It should be a relatively simple matter of scaling coils __ Designed by Harry Lythall-SM0VPO
2N2222 40 Meter CW/DSB Transceiver - In spring of 1998, NorCal sponsored a contest to design and build a project using no ICs and 22 or fewer 2N2222s as the active semiconductor devices. I thought this was a really intriguing idea, so I set about to design my version __ Designed by Monty Northrup
2-Step Power Conversion: Portable Power for the Future - Design Solutions 8 Design Notes __ Linear Technology/Analog Devices
2W / 4W audio Amplifier using paIR of LA4100, LA4101 or LA4102 Modules - Schematic only, no circuit description __ Designed by Petr Prause
2X12 W HiFi Amplifier by TD2616 - Here is the circuit of a 2X12 watt HiFi amplifier circuit using IC TDA 2616 from Phillips. A quiet simple and robust circuit using very less components. This makes the circuit ideal for a portable power amplifier. The circuit delivers 12 W power on 8 Ohm speaker for each channel at +/- 12 V dual supply
2x30W (stereo) Amplifier with STK465 - A amplifier of acoustic frequencies can be manufactured with discernible materials, despite is known so much the difficulties of finding of materials, what the problem of regulations. These difficulties are overcome relatively easily if we find amplifier in form completed __ Contact: IQ Technologies