Wednesday, November 24, 2010

200 WATT AUDIO AMPLIFIER

Output Power : 200Watts
Load Resistance : 8ohms
Input impedance : 55K
Maximum supply voltage : (+95v)-0-(-95v)
Recommended supply voltage : (+66v)-0-(-66v)

This complete high quality, low noise mono audio power amplifier is based around the Hybrid Integrated Circuit STK4050 manufactured by Sanyo. The circuit incorporates volume and has a maximum music output power of 200W. The circuit incorporates an on board power supply; therefore, only centre tapped transformer is required to power the circuit. I t has very good quality sound. U can use it with your Home Theatre your PC & etc... You can also use it as Subwoofer Amplifier. It is a compact package for THIN-TYPE Audio sets. Easy Heat sink design to disperse heat generated in THIN-TYPE audio sets. Constant-Current circuit to Reduce supply switch-ON and switch-OFF shock noise. External supply switch-On and switch-OFF shock noise muting, Load short-circuit protection, thermal shutdown and other circuits can be tailored-designed.
[read here...]

Thursday, September 9, 2010

FM Transmitter 4Watt


TECHNICAL CHARACTERISTICS:
Stabilised tendency of catering: Vcc=12~16V
Frequency of emission: 88~108MHz
Consumption: 100~400mA
Circuit diagram:

Materially:
The resistors are 1/4W.
R1, R2 10KOhm
R3 47Ohm
C1, C2 1nF
C3 4,7uF/16V
C4, C7, C8 0~45pF trimmer
C5, C6 10pF
C9 100nF
L1 4 turns, 7mm diameter *
L3 3 turns, 7mm diameter *
L4 5 turns, 7mm diameter *
L2 RFC (resistance 1MOhm with wrapped around her inductor of enough coils from fine isolated wire. Scratch of utmost inductor and you stick in utmost the resistance making thus a parallel L-r circuit.)
T1, T2 2N2219
ANT Simple dipole l/2.
MIC IN Microphone dynamic or other type. (It can also connected to a cassette player unit)
* The inductors is air from wire of coaxial 75W or other 1mm roughly.
PCB:
Before you print it out with microsoft paints, set the screen resolution to 1280 by 1024 in order to get the correct scale

Regulations:
With the C4 we regulate the frequency.
With their C7, C8 we adapt the resistance of aerial (practically to them we regulate so that it is heard our voice in the radio as long as you become cleaner).
Notes:
The T2 wants refrigerator.
[read here...]

Friday, August 13, 2010

Radio only 1 transistor without electricity

Experts and amateurs have been Experimenting with radios without batteries since the wireless communication started.
In many designs we've seen radios that operate without power, but all are known to use the diode 1N34.
(Crystal Radio).
Although significant improvements have increased the sensitivity and selectivity of these system circuits, Performances were limited until new techniques have emerged.
Here we have the first transistor radio that works without batteries, it is powered by random electric fields are everywhere in the atmosphere.
These circuits are relatively cheap to manufacture, have more volume and better reception from the crystal radios.
This circuit is a medium wave receiver and attaches easily to frequencies from 500Khz to 11Mhz.
To get good results in the reception of radio stations, we should give great importance to the ground and the antenna.
To listen to distant and weak stations we have to use a battery 9volt parallel with the capacitor C4 with it's positive side      between R2 and C4.
The coils are in the frequency of 500-1500Khz is tight and closely wrapped.
The coils are in frequency of 1.5-11Mhz is more tighter and more closely wrapped.

[read here...]

Thursday, July 29, 2010

100W Audio Amplifier

General Description

This is an exceptionally well designed amplifier, with a lot of power reserve, high fidelity, low distortion, good S/N ratio, high sensitivity, low consumption and full protection. Having all these almost ideal characteristics this amplifier is likely to become the basic building block of your future high fidelity system, or it can also become the element that will upgrade your existing system.

How it Works

The circuit works from a symmetrical ñ 40 VDC power supply and draws a maximum current of 2.6 A. The input circuit of the amplifier is a differential amplifier built around Q4 and Q5 that employ DC feedback thus preventing any DC voltage from appearing across the speaker with the usual destructive results. Q11 acts as a current source and ensures that the input stage draws a constant current of 1 mA. The signal which appears as a voltage drop across the resistor connected in series with the collector of Q4 is used to drive the DARLINGTON pair Q3, Q2 which together with the constant current source of 7 mA that is Q10, form the driver stage. This stage operates in class A and is driving the complementary output stage Q1, Q9. The transistor Q7 is used to balance the circuit at different temperatures and must be mounted on the heatsink between the out put transistors. The feedback loop which consists of R8, R9, C2, C3 provides AC stability to the circuit. The circuit also incorporates a protection stage that makes it virtually indestructible. This protection circuit is built around Q6, Q8. If for whatever reason the output remains connected on one supply rail and the common the output is also protected from high DC voltages that could burn the speakers. The supply rails should be protected by 2 A fuses for the 8 ohm version and 3 A for the 4 ohm.

Technical Specifications - Characteristics

Output power (f=1 KHz, d=0.5 %): 100 W in 8 ohm
Supply voltage: ................  40 V
Quiescent current: ............. 50 mA
Maximum current: ............... 2.6 A
Sensitivity: . 600 mV
Frequency response: ............ 10-35000 Hz (-1 dB)
Distortion HD: ................. 0.01 %
Intermodulation dist.: ......... 0.02 %
Signal/noise: 83 dBConstruction
PLEASE READ THIS BEFORE YOU START CONSTRUCTION

To cater for those who wish to use 4 ohm speakers with this amplifier the Kit includes the necessary components for both versions. The components that differ are R3,4,17 and 23. If you build the 8 ohm version then you must also include in the circuit R28 and D7, D8 which are not used in the 4 ohm version. As you see all the components are already marked on the component side of the p.c. board. The construction is made this way much simpler. Start the construction from the pins and the jumper connections, continue with the resistors and the capacitors and last solder in place the semiconductors. Check each resistor before soldering it, to see if its colours match those in the component list. Be careful with the electrolytic capacitors because their polarity should be respected. The polarity of those capacitors is marked on their bodies and on the component side of the p.c. board. NOTE: On the p.c. board next to R2, R16 are marked two other resistors which do not appear in the circuit diagram but are included in the components. They are of 1 ohm 2 W (brown, black, gold) and must be included in the circuit. Take care when you are soldering the semiconductors because if you overheat them they can be damaged. The output transistors should be mounted on the heatsink that is included in the kit. Take care not to short circuit them with the heatsink and we recommend that you use some HTC between the transistor body and the sink in order to improve heat dissipation. Follow the diagram for the mounting of the power transistors as it shows clearly how to insert the insulators and the screws. Q7 should be made to touch the heatsink and is a good idea to use a bit of HTC between its casing and the surface of the heatsink. When you finish the construction of your project clean the board thoroughly with a solvent to remove all flux residues and make a careful visual inspection to make sure there are no mistakes, components missing and short circuits across adjacent tracks on the board. If everything is OK you can make the following connections: Input: 3 (signal), 5 (common) Output: 7 (signal), 6 (common) Supply: 1 (-40 VDC), 2 (+40 VDC) 5 (0 VDC)

Connect a milliammeter in series with the power supply, short the input of the amplifier, turn the power ON and adjust the trimmer P1 so that the quiescent current is about 50 mA. When you finish this adjustment remove the shunt from the input and connect the output of a preamplifier to it. Connect the pre amplifier to a suitable source and turn everything ON. The signal should be heard from the speakers clear and undistorted. First of all let us consider a few basics in building electronic circuits on a printed circuit board. The board is made of a thin insulating

material clad with a thin layer of conductive copper that is shaped in such a way as to form the necessary conductors between the various components of the circuit. The use of a properly designed printed circuit board is very desirable as it speeds construction up considerably and reduces the possibility of making errors. Smart Kit boards also come pre-drilled and with the outline of the components and their identification printed on the component side to make construction easier. To protect the board during storage from oxidation and assure it gets to you in perfect condition the copper is tinned during manufacturing and covered with a special varnish that protects it from getting oxidised and makes soldering easier. Soldering the components to the board is the only way to build your circuit and from the way you do it depends greatly your success or failure. This work is not very difficult and if you stick to a few rules you should have no problems. The soldering iron that you use must be light and its power should not exceed the 25 Watts. The tip should be fine and must be kept clean at all times. For this purpose come very handy specially made sponges that are kept wet and from time to time you can wipe the hot tip on them to remove all the residues that tend to accumulate on it.
 DO NOT file or sandpaper a dirty or worn out tip. If the tip cannot be cleaned, replace it. There are many different types of solder in the market and you should choose a good quality one that contains the necessary flux in its core, to assure a perfect joint every time.
DO NOT use soldering flux apart from that which is already included in your solder. Too much flux can cause many problems and is one of the main causes of circuit malfunction. If nevertheless you have to use extra flux, as it is the case when you have to tin copper wires, clean it very thoroughly after you finish your work. In order to solder a component correctly you should do the following:

  • Clean the component leads with a small piece of emery paper. - Bend them at the correct distance from the component body and insert the component in its place on the board.

  • You may find sometimes a component with heavier gauge leads than usual, that are too thick to enter in the holes of the p.c. board. In this case use a mini drill to enlarge the holes slightly. Do not make the holes too large as this is going to make soldering difficult afterwards.

  • Take the hot iron and place its tip on the component lead while holding the end of the solder wire at the point where the lead emerges from the board. The iron tip must touch the lead slightly above the p.c. board.

  • When the solder starts to melt and flow, wait till it covers evenly the area around the hole and the flux boils and gets out from underneath the solder. The whole operation should not take more than 5 seconds. Remove the iron and leave the solder to cool naturally without blowing on it or moving the component. If everything was done properly the surface of the joint must have a bright metallic finish and its edges should be smoothly ended on the component lead and the board track. If the solder looks dull, cracked, or has the shape of a blob then you have made a dry joint and you should remove the solder (with a pump, or a solder wick) and redo it.

  • Take care not to overheat the tracks as it is very easy to lift them from the board and break them.

  • When you are soldering a sensitive component it is good practice to hold the lead from the component side of the board with a pair of long-nose pliers to divert any heat that could possibly damage the component.

  • Make sure that you do not use more solder than it is necessary as you are running the risk of short-circuiting adjacent tracks on the board, especially if they are very close together.

  • When you finish your work cut off the excess of the component leads and clean the board thoroughly with a suitable solvent to remove all flux residues that still remain on it.
If it does not work

Check your work for possible dry joints, bridges across adjacent tracks or soldering flux residues that usually cause problems. Check again all the external connections to and from the circuit to see if there is a mistake there.


  • See that there are no components missing or inserted in the wrong places.

  • Make sure that all the polarised components have been soldered the right way round. - Make sure the supply has the correct voltage and is connected the right way round to your circuit.

  • Check your project for faulty or damaged components. If everything checks and your project still fails to work, please contact your retailer and the Smart Kit Service will repair it for you.





L1 : 10 turns with wire 0,5mm turned on a restistor of 1W

If you use a 4Ohm speaker you will place R3,4,17,23 at the board.

If you use a 8Ohm speaker you will place D7 D8 and R28.

For R2 and R16 if you don't find a 0,47Ohm place two of 1 Ohm parallel.

R16 must be 0,47Ohm...the 1Ohm must be a typographical error, take care of this, i haven't tested it.
[read here...]

Wednesday, July 7, 2010

1V, Low-Power, Stereo Headphone Amplifier with Shutdown (MAX9725)

The MAX9725A–MAX9725D fixed-gain, stereo headphone amplifiers are ideal for portable equipment where board space is at a premium. The MAX9725E offers the flexibility to adjust the gain with external input and feedback resistors. The MAX9725A–MAX9725E use a unique DirectDrive® architecture to produce a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. Fixed gains of -2V/V (MAX9725A), -1.5V/V (MAX9725B), -1V/V (MAX9725C), and -4V/V (MAX9725D) further reduce external component count. The adjustable gain of the MAX9725E DirectDrive headphone amplifier allows for any gain down to -1V/V using external resistors.

The MAX9725 delivers up to 20mW per channel into a 32
Ω
load and achieves 0.006% THD+N. An 80dB at 1kHz power-supply rejection ratio (PSRR) allows the MAX9725 to operate from noisy digital supplies without an additional linear regulator. The MAX9725 includes ±8kV ESD protection on the headphone output. Comprehensive click-and-pop circuitry suppresses audible clicks and pops at startup and shutdown. A low-power shutdown mode reduces supply current to 0.6µA (typ).

The MAX9725 operates from a single 0.9V to 1.8V supply, allowing the device to be powered directly from a single AA or AAA battery. The MAX9725 consumes only 2.1mA of supply current, provides short-circuit protection, and is specified over the extended -40°C to +85°C temperature range. The MAX9725 is available in a tiny (1.54mm x 2.02mm x 0.6mm) 12-bump chip-scale package (UCSP™) and a 12-pin thin QFN package (4mm x 4mm x 0.8mm).


Download MAX9725 Datasheet

[read here...]

Sunday, June 27, 2010

Amplifier 250-500W with transistors MJ15003.



GENERAL DISCRIPTION :The circuit is based around (TL 071) manufactured by NATIONAL semiconductors (MJ15003) by ON semiconductors It is a high fidelity audio power amplifier. Designed for demanding consumer and pro-audio applications. You can also use this circuit with AV receivers, Audiophile power amps, Pro Audio High voltage industrial applications etc Amplifier output power maybe scaled by changing the supply voltage and number of output devices.

General Specifications
Rated Power Output
(20Hz to 20kHz Continuous Average Sine Wave)
250 watts into 8 ohms
500 watts into 4 ohms
Power Bandwidth
(250 watts into 8 ohms)
20Hz to 40kHz (0dB to -3dB)
Frequency Response
1 watt into 8 ohms
20Hz to 100kHz (0dB to -1.0 dB)
250 watts into 8 ohms
20Hz to 20kHz (Flat)
Input Sensitivity
+3 dBV
(1.4V RMS produces an output of 350 watts into 8 ohms)
Input Impedance
33K ohms, Unbalanced
Rise Time
2.0 microSeconds
Total Harmonic Distortion (THD)
Full Power(250 watts into 8 ohms)
Less than 0.007 % THD @ 1kHz
Less than 0.08 % THD @ 20Hz to 20kHz
Half Power (125 watts into 8 ohms)
Less than 0.003 % THD @ 1kHz
Less than 0.03 % THD @ 20Hz to 20kHz
10 watts into 8 ohms
Less than 0.003 % THD @ 1kHz
Less than 0.01 % THD @ 20Hz to 20kHz
[read here...]

Wednesday, June 23, 2010

FM Stereo Transmitter ( BH1415F )

This Electronic circuit is a stereo FM Transmitter based on BH1415F wireless audio link IC. Phase Locked Loop (PLL) controller use PIC16F628 and the the PLL frequency programming can be displayed with 8x2 and 16x2 LCD. Frequency Range 88-108 MHz

BH1415F can be supplied with 6 - 15V voltage, consumes only around 25mA while providing very sound quality and improved 40dB channel separation. BH1415 is only available in SOP22 IC case and this may be an inconvenience for some folks. On the other hand, because the chip is smaller than regular DIP-based ICs it is possible to fit the entire stereo coder on a small PCB.

[read here...]

Sunday, June 13, 2010

240VAC TO 5VDC POWER SUPPLY


This is simple way to power some 5v logic from a 240vac source. If a 120vac power adapter is used, the circuit will also work for 120vac power lines.


[read here...]

Monday, May 31, 2010

20 LED AUDIO VU METER

This circuit has 3 main sections, an inverting op-amp amplifier, a rectifier and LED display. The input can be from almost any low level source, but if not using an electret microphone, then omit R1 as it's not necessary. The gain of the amplifier based around IC1 is controlled by VR1. The output is rectified by D1,2 and filtered using C4,R6.The final stage is a standard design for the LM3914. Alter R8 to control LED brightness but be careful not to over-drive the IC's. It's recommended that you don't


[read here...]

Friday, May 7, 2010

TDA1562Q . . . 50W from a 12 V battery (Elektor 2/2000)



The integrated output amplifier described in this article consists of little more than one integrated circuit. It is intended especially for use in motor vehicles and other batteryoperated applications. Although it appears simple and hardly worth looking at, the amplifier can produce an appreciable audio power output.

technical data
Properties
High power output through Class-H operation
Low power dissipation during reproduction of music signals
Proof against short-circuits
Protection against excessive temperatures
Standby switch
No power-on or power-off clicks
Visible error indication
Measurement results (at Ub=14.4 V)
Supply voltage 8–18 V
Sensitivity 760 mV r.m.s.
Input impedance 70 kΩ
Power output 54 W r.m.s. into 4 Ω (f=1 kHz; THD+N=1%)
Harmonic distortion (THD+N) at 1 W into 4 Ω: 0.046% (1 kHz)
0.29% (20 kHz)
at 35 W into 4 Ω: 0.12% (1 kHz)
0.7% (20 kHz)
Signal-to-noise ratio (with 1 W into 4 Ω) 88 dBA
Power bandwidth 7.5 Hz – 185 kHz (at 25 W into 4 Ω)
Quiescent current about 135 mA (‘on’)

COMPONENTS LIST
Resistors:
R1 = 1MΩ
R2 = 4kΩ7
R3 = 1kΩ
R4 = 100kΩ
Capacitors:
C1,C2 = 470nF
C3,C4 = 10μF 63V radial
C5,C6,C8 = 4700μF 25V radial
(18mm max. dia., raster 7.5 mm)
C7 = 100nF, raster 5 mm
Semiconductors:
D1 = high-efficiency-LED
IC1 = TDA1562Q (Philips)
Miscellaneous:
S1 = single-pole on/off switch
Four spade connectors, PCB mount
Heatsink for IC1 (Rth<2.5>
[read here...]

Monday, April 19, 2010

LM3876 - High-Performance 56W Audio Power Amplifier with Mute


The LM3876 is a high-performance audio power amplifier capable of delivering 56W of continuous average power to an 8 load with 0.1% THD+N from 20Hz-20kHz.The performance of the LM3876, utilizing its Self Peak Instantaneous Temperature protection circuitry, puts it in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area. Speaker protection means that these parts are completely safeguarded at the output against overvoltage, undervoltage, overloads, including shorts to the supplies, thermal runaway, and instantaneous temperature peaks.The LM3876 maintains an excellent signal-to-noise ratio of greater than 95dB (min) with a typical low noise floor of 2.0µV. It exhibits extremely low THD+N values of 0.06% at the rated output into the rated load over the audio spectrum, and provides excellent linearity with an typical rating of 0.004%.

Features

56W continuous average output power into 8Ω

100W instantaneous peak output power capability

Signal-to-Noise Ratio >= 95 dB(min)

An input mute function

Output protection from a short to ground or to the supplies via internal current limiting circuitry

Output over-voltage protection against transients from inductive loads

Supply under-voltage protection, not allowing internal biasing to occur when VEE + VCC <= 12V, thus eliminating turn-on and turn-off transients

11-lead TO-220 package

Wide supply range 20V - 94V

Part list

Resistor:
R1, R3 = 1 k
R2, R4, R5 = 18k
R6 = see text
R7 = 10R, 5 Watt
R8, R9 = 22k

Capacitors:
C1 = 2.2 uF
C2 = 220 uF, 160 V
C3 = 22 uF, 40 V
C4 = 47 pF
C5 = 100 uF, 40 V
C6 = see text
C7, C8 = 100 nF
C9, C10 = 1000 uF, 40 V
Inductors:
L1 = 0.7 uH – see text

Integrated circuits:
IC1 = LM3876T

Miscellaneous:
Heat sink for IC1

Air-cored inductor L1 consists of 13 turns of 1mm dia. enamelled copper wire with an inner diameter of 10mm. The completed inductor is pushed over R7 and its terminals soldered to those of the resistor. All electrolytic capacitors must be mounted upright. The amplifier can be muted with a single-pole switch connected to the MUTE input (pin8). This function is enabled when the switch is open. If muting is not required, solder a wire bridge across the mute terminals on the board. The R6-C6 is not normally required in this application, but provision has been made for it for use in other applications. According to the manufacturers, both chips are optimalized for a load of 8 Ohm. The output power is lower when a 4 Ohm load is used or when the supply voltage is reduced. When a 4 Ohm load is used, the SPIKE protection becomes active when the supply voltage is about 27V, resulting a in a reduction of the power output to 10W. This means that it is not advisable to use loudspeaker with an impedance

[read here...]

Sunday, April 18, 2010

LM1875 - POWER AMPLIFIER 20 WATT


The LM1875 is a monolithic power amplifier offering very low distortion and high quality performance for consumer audio applications.
The LM1875 delivers 20 watts into a 4Ω or 8Ω load on ±25V supplies. Using an 8 load and ±30V supplies, over 30 watts of power may be delivered. The amplifier is designed to operate with a minimum of external components. Device overload protection consists of both internal current limit and thermal shutdown.
The LM1875 design takes advantage of advanced circuit techniques and processing to achieve extremely low distortion levels even at high output power levels. Other outstanding features include high gain, fast slew rate and a wide power bandwidth, large output voltage swing, high current capability, and a very wide supply range. The amplifier is internally compensated and stable for gains of 10 or greater.

Features

• Up to 30 watts output power
• AVO typically 90 dB
• Low distortion: 0.015%, 1 kHz, 20 W
• Wide power bandwidth: 70 kHz
• Protection for AC and DC short circuits to ground
• Thermal protection with parole circuit
• High current capability: 4A
• Wide supply range 16V-60V
• Internal output protection diodes
• 94 dB ripple rejection
• Plastic power package TO-220
[read here...]

Wednesday, March 17, 2010

2.5 GHz Frequency Counter with Blue 2x16 LCD display


This project explain a very powerful frequency counter which has many useful software functions.
The software can add or subtract 3 different IF frequencies (±455 kHz ,±10.7 MHz and ±21.4 MHz).
You have also two level of resolutions, 1kHz and 100Hz.
The main oscillator can be on-board 13MHz or external 10 MHz.
The counter data can easy be transmitted to computer with RS232 cable (software below)
The construction is extremely simple and the unit is very small.
This project comes in a KIT version, se more details below.


Background
Once again, It is time to update the frequency counter.
A frequency counter is one of the most important measuring tool we need as homebrew's of RF electronic.
This frequency counter has very high performance and still is very easy to build and to use.
Anyone can build it and have a professional frequency measuring tool.
The counter is based around a LCD display with 2 lines and 16 chars.
I have used a HD44780 based display which is very common.
A PIC16F870 circuit controls all counting and display functions.
A prescaler is added to make it possible to measure up to 2.5GHz with high sensitivity.

The Display Module Size (W x H x T): 80mm X 36mm.
The controller PCB has the same size. This makes the unit very small and slim.

In the menu system of this frequency counter, you can choose between two reference frequencies.

· On-board 13.000MHz crystal (picture at right), or

· External 10.000MHz signal.
The reason of using a external 10.000 MHz reference frequency is because it is common among reference oscillators, as HP Z3801 GPS locked frequency source.





[read here...]

Wednesday, January 27, 2010

6H9C-6П13С PUSH-PULL TUBE AMPLIFIER


Features:
The output stage: push-pull, class A, with a fixed offset in 6P13S tubes in triode switch.
Output Power - 10.5 W
Band Frequency - 25Hz ... 30kHz
Sensitivity - 0.707V (1V amplitude)
THD - 1.5% (before clipping), 0.8 ... 0.9% (half power)
The level of background noise on the output - 1.5 mV



[read here...]

Monday, January 11, 2010

TUBE DISTORTION


-
IC1---LM747 dual op-amp, others may be substitued but pinout will differ
IC2---LM340K 12 Voltage Regulator
Bridge Rectifier - Full wave bridge rectifier, 50Volts, 500ma minimum
All resistors 1/2Watt, 10% prefered


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[read here...]

Sunday, January 10, 2010

30 W AMPLIFIER FOR CARS

Design by T. Giesberts

ELEKTOR ELECTRONICS MARCH 1995


The power that can be obtained from a standard car radio amplifier operating from a 12 V car battery is 5–6W, which (for many listeners) is not really enough for satisfactory hi-fi reproduction. It is, of course, possible to boost the 12 V supply with a power inverter, but that is fairly expensive and not always acceptable. Now, a Philips IC enables audio power of about 30 W to be obtained from a 12 V car battery. MORE...

Technical Data
Class H operation
Low dissipation with music signals
Extensive protection circuits (output current; temperature; load impedance)
Supply voltage 12 V nominal
Quiescent current 100 mA
Output power
(1 kHz sinusoidal, THD = 0.5%) 30 W r.m.s. into 8 Ω
(music signal) 40 W into 8 Ω
THD + noise (1 W into 8 Ω = 0.05% (20 Hz to 20 kHz)
THD + noise (20 W into 8 Ω = 0.2% (20 Hz to 20 kHz)
Power bandwidth (–3 dB) 5 Hz to 100 kHz.

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[read here...]

Monday, January 4, 2010

Power Amplifier 1500W - 4OHMS



This project is mainly in answer to those for whom no amount of power is enough. I have lost count of the number of times people have asked if it's alright to increase the supply voltage on every circuit published, and in general the answer is no - it's not alright. Every design on this site is optimised for the stated power. There is always some flexibility, but you must be very careful to make sure that transistor safe operating area (SOA) is not exceeded. There is also a maximum voltage for any semiconductor, and devices must be selected to ensure they are used within their ratings. MORE...

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[read here...]

ONE TUBE BROADCASTER


The purpose of this broadcaster is to transmit your favorite music to every AM radio in your home. The transmitting power is so low that it should not bother the neighbors. A common application would be to drive it from the speaker leads of your FM radio, which could then include playing your XM or Sirius to your AM sets, or just your favorite FM station. MORE....


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[read here...]