Thursday, October 25, 2007

Zeus MOSFET Matching

L200 current source mosfet matching circuit.
  • Use 12 volts for IC1 (STMicroelectronics L200) Vsupply.

  • Digital voltmeter to three decimal places at 2 to 6 volts recommended.

  • Current set to 500mA (higher current cause device heating).

  • Mount DUTs on common heatsink as per picture.

  • Allow reading to stabilize (about 10 seconds) before noting value.

  • Once close matches have been ascertained retest those matches to get best fits.

Read more source : http://www.susan-parker.co.uk/zeus-mosfet-matching-1.htm

The ORIGINAL ROCKFORD FOSGATE PUNCH AMP/ MOSFET POWER


This is for a Older model ROCKFORD FOSGATE PUNCH 75 MOSFET AMPLIFIER. This holds power unlike the newer models. The Punch 75 is 37.5 watts RMS continuous power per channel into four phms with less than 05% total hormonic distortion from 20-20000 HZ.
The side shows Bass 0-18+ and Treble 0-12+.

Read more source : http://atlanta.craigslist.org/ele/453888768.html

MOSFET Integrated Amplifier

This is my first attempt at building a "proper" amplifier for general use, as opposed to the Mixer-Amplifier I had made earlier. This amp was made without too much concern to cost, hence several of the approaches I've taken may be sub-optimal from the cost perspective.

Overview

  • Microcontroller-controlled preamplifier, with infrared remote control capability. Volume and other settings stored in battery-backed RAM.
  • LCD Display for volume, etc.
  • Three general-purpose line-level inputs, one tape input, one tape output.
  • 70W MOSFET-based stereo power amplifier.
  • Headphone output.
  • +/-38V at 4A and +/-5V at 500mA power supplies.
Read more source : http://wiredworld.tripod.com/tronics/mosfet_amp.html

High Power, High Fidelity MOSFET Power Amplifier

In various parts of The Audio Pages, I have said that I am not a fan of MOSFET power amplifiers. Well, this amp has changed my views, and I consider this to be a "reference" system in all respects. The performance is extremely good, with vanishingly low distortion levels, plenty of power, very wide full power bandwidth, and the "self protecting" nature of the MOSFETs themselves.

Read more source : http://sound.westhost.com/project101.htm

Lanzar 4000 watt 2 Channel Car AMP Mosfet POWER

SPECS
2 x 1000 Watts RMS at 4 Ohms 2 x 2000 Watts Max at 4 Ohms 1 x 4000 Watts Max at 4 Ohms Bridged 2 x 1650 Watts at 2 Ohms RMS Electronic Crossover Network Bass Boost Circuit Variable Phase Shift Control 2 Ohms Stereo Stable Anti-Thump Turn-On Soft Turn On/Off High & Low Level Inputs Blue Light Illuminated Crossover Control Power & Protection LED Indicators Advanced Protection Circuitry Bass Boost Remote Control T.H.D: 0.04% S/N Ratio: 90dB Channel Separation: 65dB Frequency Response: 15Hz- 35kHz Dimensions: 10.47''W x 2.46''H x 21''L

Read more source : http://philadelphia.craigslist.org/ele/459149485.html

Tuesday, October 23, 2007

App Note 16 - SOA Advantages of MOSFETS

App Note 16 - SOA Advantages of MOSFETS: Apex Microtechnology Cor.

AN-D26: HT04 Series: High Voltage Isolated MOSFET Driver

AN-D26: HT04 Series: High Voltage Isolated MOSFET Driver: Supertex Semiconductors

AN-D15: Understanding MOSFET Data

AN-D15: Understanding MOSFET Data: Supertex Semiconductors

AN898: Determining MOSFET Driver Needs for Motor Drive Applications

AN898: Determining MOSFET Driver Needs for Motor Drive Applications

AN799: Matching MOSFET Drivers to MOSFETs

AN799: Matching MOSFET Drivers to MOSFETs

AN798: Universal Power MOSFET Interface IC (TC4420/9)

AN798: Universal Power MOSFET Interface IC (TC4420/9)

AN786: Considerations for Driving Power MOSFETs in High-Current, Switch Mode Regulators

AN786: Considerations for Driving Power MOSFETs in High-Current, Switch Mode Regulators

AN763: Latch-Up Protection for MOSFET Drivers

AN763: Latch-Up Protection for MOSFET Drivers

AN-6005 / Synchronous buck MOSFET loss calculations with Excel model

AN-6005 / Synchronous buck MOSFET loss calculations with Excel model

AN-558: Introduction to Power MOSFETs and Their Applications

AN-558: Introduction to Power MOSFETs and Their Applications: National Semiconductor.

AN18 Power MOSFET Gate Driver Circuits using High Current Super-b Transistors: 6A Pulse Rated SOT23 Transistors for High Frequency MOSFET Interfacing

AN18 Power MOSFET Gate Driver Circuits using High Current Super-b Transistors: 6A Pulse Rated SOT23 Transistors for High Frequency MOSFET Interfacing: Zetec Semiconductors A description of the MOSFET converter circuits' requirement for a high current buffer stage, a suggested range of Zetex high current capable, fast switching transistors, and circuit examples.

AN10 Automotive Relay Drivers using the Zvn4206av: Protection Free Interfacing with Avalanche Rated MOSFETs

AN10 Automotive Relay Drivers using the Zvn4206av: Protection Free Interfacing with Avalanche Rated MOSFETs: Zetec Semiconductors An alternative solution is provided to the usual large package Darlington effected relay driver. The ZVN4206AV has been designed, processed and rated to withstand significant energy within the breakdown region. This allows the part to absorb back-emf and transient energy, thereby allowing lower component count circuits.

Amplify and Shift EPAD MOSFET Output with an Operational Amplifier

Amplify and Shift EPAD MOSFET Output with an Operational Amplifier: Circuit Ideas for Designers Advanced Linear Devices, Inc.

Ampli MOSFET

Ampli MOSFET : DIY high power MOSFET amplifier200 Wrms 8 ohms -350 Wrms4 ohms

Advanced Polarity Protection with MOSFETs

Advanced Polarity Protection with MOSFETs: Advanced Power Switching and Polarity Protection for Effects

AB-15 / Using Surface Mount Power MOSFETs in Processor Power Supplies

AB-15 / Using Surface Mount Power MOSFETs in Processor Power Supplies

A 300w MOSFET Linear Amplifier for 50 Mhz

A 300w MOSFET Linear Amplifier for 50 Mhz: Advanved Power Technology - APT980

25 Watt MOSFET Amplifier

25 Watt MOSFET Amplifier: High Quality simple unit. No need for a Preamplifier

2N2222 40 Meter CW/DSB Tranceiver


power Redefined

The Hx350 is the epitome of power.

With 10 pieces of IRFP240/9240, it is capable of delivering an astounding 600Watts/RMS into 4 W (before clip).

But the Hx350 is more than raw power. It's about the quality of Watts. It has none of the edginess and harshness that proamps are notorious for. When used in the home, the Hx350 is ideally suited for high powered subwoofers or power hungry main speakers.

The Hx350 is the only amplifier in AmpsLab with our Loudspeaker Protection Circuitry (DCpro Kit) on board.

Read more source : http://www.ampslab.com/hx350.htm

Lateral Mosfets

The Lm60 uses a pair of highly acclaimed Hitachi Lateral Mosfets 2SK1058 & 2SJ162 for the current stage.

These mosfets are reputed to be the only transistors manufactured solely for audio applications. Unlike normal power transistors, the Hitachi Mosfets do not suffer from Secondary Breakdown. Best of all, they are immune to Thermal Runaway.

In musical reproduction, the Lm60 is probably the sweetest sounding amplifier in AmpsLab. Highly recommended for tube aficionados who are migrating to solid state.

Read more source : http://www.ampslab.com/lm60.htm

Switching Mosfets

The new generation of Switching Mosfets, IRFP240/9240, are making sweeping changes in power amplification.

Since these mosfets do not suffer from Secondary Breakdown, they are fast gaining reputation as the preferred choice in the professional industry.

The Hx series in AmpsLab takes full advantage of this new technology. We highly recommend our Hx amplifiers for Home Theater Systems.
The new generation of Switching Mosfets, IRFP240/9240, are making sweeping changes in power amplification.

Read more source : http://www.ampslab.com/hx100.htm

Since these mosfets do not suffer from Secondary Breakdown, they are fast gaining reputation as the preferred choice in the professional industry.

The Hx series in AmpsLab takes full advantage of this new technology. We highly recommend our Hx amplifiers for Home Theater Systems.

Monday, September 3, 2007

LM1875 Channel Stereo Power Amplifier 20 Watt

LM1875 Channel Stereo Power Amplifier 20 Watt
There are many instances where a simple and reliable power amplifier is needed - rear and centre channel speakers for surround-sound, ...

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Simple Class A Amplifier 10W with MJ480

10 Watt Power Amplifier:

Simple Class A Amplifier

A 10-W Design giving subjectively better results than class B transistor amplifiers

Thursday, August 23, 2007

MJE3055+MJE2955 Power Amplifier 60 Watt Into 8 Ohms

Introduction
This amplifier does not claim to be "state of the art", and in fact the base design is now over 20 years old. It is a simple amp to build, uses commonly available parts and is stable and reliable.
...

Link : MJE3055+MJE2955 Power Amplifier 60 Watt Into 8 Ohms

Sunday, July 29, 2007

TDA2005 - Schematic audio amplifier

TDA2005 - Schematic audio amplifier

Soft-Start Circuit For Power Amps

When your monster (or not so monster) power amplifier is switched on, the initial current drawn from the mains is many times that even at full power. There are two main reasons for this, as follows ...

  • Transformers will draw a very heavy current at switch on, until the magnetic flux has stabilised. The effect is worst when power is applied as the AC voltage passes through zero, and is minimised if power is applied at the peak of the AC waveform. This is exactly the opposite to what you might expect
  • At power on, the filter capacitors are completely discharged, and act as a short circuit for a brief (but possibly destructive) period
These phenomena are well known to manufacturers of very high power amps used in PA and industrial applications, but 'soft start' circuits are not commonly used in consumer equipment. Anyone who has a large power amp - especially one that uses a toroidal transformer - will have noticed a momentary dimming of the lights when the amp is powered up. The current drawn is so high that other equipment is affected.

READ MORE ...

Saturday, July 28, 2007

GRE- Complete information-Test tips

GREThe GRE is now only available as a computer-adaptive test. This is how it works: instead of having a pre-determined mixture of easy, medium, and hard questions, the computer will select questions for you based on how well you are doing. The first question will be of medium difficulty; if you get it right, the second question will be selected from a large group of questions that are a little

Friday, July 27, 2007

google

GRE Word List

Commonly Used GRE Words abateto lessen to subside abdicationgiving up control authority aberrationstraying away from what is normal abethelp/encourage smb (in doing wrong) abeyancesuspended action abhorto hate to detest abidebe faithful to endure abjurepromise or swear to give up abradedrubbed off worn away by friction abrogaterepeal or annul by authority abscondto go away suddenly (to avoid

Thursday, July 26, 2007

TOEFL

TOEFLTOEFL iBT was introduced in the United States, Canada, France, Germany, Italy, and Puerto Rico in 2005. The second phase of the rollout began on March 25, 2006, when test centers in selected cities in Africa, the Americas, Europe, Eurasia, the Middle East, and North Africa offered TOEFL iBT for the first time. A list of cities where TOEFL iBT is being introduced is posted in the Learners and

GRE WORD LIST

The word lists below are presented in the same order that I learned them in 1998 when I was preparing for a GRE test. Before printing and carrying the lists with you all the time, you should think for a while if you could benefit from the lists, and if you suppose so, how you could use them. The lists were really helpful to me, but it may not be the case for you; they may contain some words which

The Test Format

There are four sub-tests, or modules, to the IELTS test: Reading, Writing, Listening and Speaking. Students must sit all four sub-tests. While all students take the same Listening and Speaking tests, they sit different Reading and Writing tests, depending on whether they have selected the Academic IELTS test or the General Training IELTS test.On the day of the test, the four subsections will be

IELTS English language exam

What is IELTS?IELTS stands for International English Language Testing System. It is an internationally-recognised system for testing English language skills in listening, reading, writing and speaking.Why take an IELTS exam?IELTS is recognised by many universities and can be used to support visa applications. If you want to work or study abroad, an IELTS qualification is essential. You can also

Saturday, July 21, 2007

Audio power amplifier schematics

Source : http://www.district87.org/staff/waltonm/CircuitAnalysis/Electronic%20circuit%20schematics.htm
Thank you

Sunday, July 15, 2007

30 Watt Power Amplifier

30 Watt Power Amplifier

4QD-TEC: Electronics Circuits Reference Archive
Low distortion audio amplifier

30 Watt Amplifier

30 Watt Amplifier Schematic

20 Watt Power Amplifier

20 Watt Power Amplifier
This IC chip was designed specifically for use in power boosting applications in automobiles.

100W RMS Amplifier

100W RMS Amplifier

This is a 100 watt basic power amp that was designed to be (relatively) easy to build at a reasonable cost.

100W RMS Amplifier

100W RMS Amplifier

This is a 100 watt basic power amp that was designed to be (relatively) easy to build at a reasonable cost.

100W Guitar Amplifier

100W Guitar Amplifier Mk II
Rod Elliott (ESP)
New Version Created 27 Jan 2002

Simple Class A Amplifier 10W

Simple Class A Amplifier

A 10-W Design giving subjectively better results than class B transistor amplifiers

by J. L. Linsley Hood, M.I.E.E.

Tuesday, June 5, 2007

Friday, June 1, 2007

TDA2009 Ampl BCL 18W


circuit-TDA2009 Ampl BCL (bridge amplifier) 18W ,Supply volt = 23V 2A

TDA2020 power amp 80W hi-fi

circuit TDA2020 power amp 80W hi-fi
For this application the maximum value of V1 in no-load condition is +/- 45V

Wednesday, May 30, 2007

TDA2004 Headphone amplifier

A opamp. medium power, here it�s used as amplifier of headphones with possibility drive low loads. It contains in a nutshell two amplifiers. The voltage gain, has been determined in 40dB, from the R3-4 and R11-12, for each channel, respectively. The restriction of bandwidth for each unit is regulated by the combination of R12, C2 and R13, C15, in 22KHZ. The R5, R10 attend to the adaptation of impedance earphones.

Link: TDA2004 Headphone amplifier

300W Power Amplifier OCL by transister

Source :: http://users.otenet.gr/~athsam/power_amp_300w.htm


For many application there's no substitute for sheer power- low efficiency speakers, outdoor sound systems, or maybe you like the full flavour of the dynamic range of a high power amp. Whatever your requirement-this super power module should fit the bill. How it works: The amplifier can be divided into three separate parts. These are : the input stage, which consists of Q1-Q9 , a high gain, low power driver; the output or power stage- witch only has a voltage gain of four but enormous power gain; and the power supply. The input stage is a complementary -differential network, each ''side'' with its own current source. Each transistor in this stage is run at a collector currant of about 0.7mA. Emitter resistors are employed to stabilize the gain and improve linearity. The output of Q1-Q5 drives Q7 and Q9. The latter are virtually two constant-current sources run about 7mA collector current. With an input signal these ''current'' sources are modulated out of phase - the collector current of one decreases while the other increases. This configuration provides quite an amount of gain. In between the bases of these two transistors is Q8, the thermal sensing-bias transistor. The voltage across Q8 may be adjusted by TR1, thus setting the quiescent bias current for output stage. The output stage, Q10-Q11, Q13-Q14 and Q16-17, has a gain of about five, set by R44 and R28 plus R29. Diodes D4 and D6 prevent reverse biasing of Q10 and Q11 (otherwise the output would be limited). Protection of the output transistors is provided by Q12 and Q15 which monitor both current and voltage in the output transistors and bypass the base current if the limit is exceeded. Frequency stabilization provided by capacitors C6, C11, C12 and the RC networks R31/C10 plus R46/C15. Frequency response of the amplifier is set by C1 and C7 (lower limit), C6 sets the upper frequency limit. If you want use the Protection DC and Balance/Bridge circuits. All the transistors that are inside the interrupted line are placed on an aluminium corner and he screwed on a suitable heatsink. The transistors Q7,Q10,Q11, Q8, Q9, Q13,Q14,Q16 and Q17 placed on this aluminium corner, with suitable isolation from this.


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300W Power Amplifier OCL by transister

Tuesday, May 29, 2007

circuit power amp OTL 100W by transistor 2N3055 (with PCB)

This is Circuit Power Amp OTL 100W by transistor 2N3055.
It easy to build because normal circuit power amp OTL.
To use power supply 98V 5A.
Out put power 100W at Speaker 8 OHM or 120W : 4OHM.

View circuit and PCB power amp OTL 100W by transistor 2N3055 (with PCB)
View Circuit Power Supply 98V 5A FOR power amp OTL 100W by transistor 2N3055

circuit power amp mosfet ocl 60W by K134 and J49

This is circuit power amp mosfet ocl 60W, it use mosfet K134 and J49.
Out put power 60W at speaker 8 ohm or 120W at 4 ohm.
It easy circuit.
supply volt +49V gnd +49V ,Curent 3-5A.

Read More and View circuit power amp mosfet ocl 60W by K134 and J49

Thursday, May 24, 2007

Pre MIC (microphone preamplifier) 2 CH by IC NE5532 or LF353


Circuit Pre MIC (microphone preamplifier) 2 CH by IC NE5532 or LF353

PCB Pre MIC (microphone preamplifier) 2 CH by IC NE5532 or LF353

Monday, May 14, 2007

5 Channels Graphic Equaliser by LA3600

This circuit 5 Channels 2 Octave Graphic Equaliser,easy to make equalizer,
because using IC LA3600 (easy to use)
Cut at frequencies of 50Hz, 200HZ,800Hz,3.2kHz and 10kHz.
Supply voltage may be anything from +12V.

Read more and View Circuit
5 Channels Graphic Equaliser by LA3600

5 Channels 2 Octave Graphic Equaliser by 4558

This circuit 5 Channels 2 Octave Graphic Equaliser,easy to make equalizer,
because using IC 4558 or 1458 or LF353 (nice)
Cut at frequencies of 50Hz, 200HZ,800Hz,3.2kHz and 12kHz.
Supply voltage may be anything from -15V GND -15V for IC 4558.

View Circuit 5 Channels 2 Octave Graphic Equaliser by 4558 with PCB

Sunday, May 13, 2007

Saturday, May 12, 2007

TDA1910 monolithic integrated circuit.

The circuit TDA1910 monolithic integrated circuit.
* 10 dB 50Hz boost tone control using change of pin 1 resistane (muting fumction)

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TDA1910 monolithic integrated circuit.

TDA1910 Sqelch function in TV

The circuit TDA1910 Sqelch function in TV, INPUT Sound IF 5.5MHZ.

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TDA1910 Sqelch function in TV

TDA2003 Amplifier BCL (Low cost) 18W for CAR

The Circuit TDA2003 Amplifier BCL (bridge amplifier) 18W for CAR CAR RADIO AUDIO.
Volt supply 10V-14V, Power output 18W, for Speaker 2-8 ohm.

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TDA2003 Amplifier BCL (low cost) 18W for CAR

TDA2003 Amplifier Car Audio OTL 10W

The Circuit TDA2003 Amplifier BCL 10W CAR RADIO AUDIO.
Volt supply 10V-14V, Power output 8W, for Speaker 2-8 ohm.

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TDA2003 Amplifier Car Audio OTL 10W


TDA2003 Amplifier Car Audio OTL 10W

The Circuit TDA2003 Amplifier OTL 10W CAR RADIO AUDIO.
Volt supply 10V-14V, Power output 8W, for Speaker 2-8 ohm.

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TDA2003 Amplifier Car Audio OTL 10W

Friday, May 11, 2007

TDA2002 Amplifier 8W CAR RADIO AUDIO

The Circuit TDA2002 Amplifier 8W CAR RADIO AUDIO.
Volt supply 10V-14V, Power output 8W, for Speaker 2-8 ohm.

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TDA2002 Amplifier 8W CAR RADIO AUDIO

TDA1910 Amplifier OTL 10W - with muting

The circuit TDA1910 Amplifier OTL 10W - without muting.
Volt supply 10V-14V, Power output 10W, for Speaker 2-8 ohm.

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TDA1910 Amplifier OTL 10W - with muting

TDA1910 Amplifier OTL 10W - without muting

The circuit TDA1910 Amplifier OTL 10W - without muting.
Volt supply 10V-14V, Power output 5W, for Speaker 2-8 ohm.

Read more and View Circuit

circuit TDA1908 Amplifier CAR AUDIO OTL 8W

The circuit TDA1908 Amplifier CAR AUDIO OTL 8W.
Volt supply 10V-14V, Power output 5W, for Speaker 2-8 ohm.

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TDA1908 Amplifier CAR AUDIO OTL 8W

TDA1905 Amplifier CAR Audio OTL 5W

The circuit TDA1905 Amplifier CAR Audio OTL 5W.
Volt supply 7-14V, Power output 5W, for Speaker 2-8 ohm.

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TDA1905 Amplifier CAR Audio OTL 5W

TDA1904 Audio Amplifier OTL 4W

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TDA1904 Audio Amplifier OTL 4W

Wednesday, May 9, 2007

50W OCL Mosfet (K1058 + J162)

The 50W OCL Mosfet (K1058 + J162) is easy to build, and very inexpensive.
To use Power Supply +35V -35V >2A.
Mosfet (K1058 + J162) must be mounted on heatsink.
Can be directly connected to CD players, tuners and tape recorders.

View Circuit and PCB 50W OCL Mosfet (K1058 + J162)

40W Amp OCL 2N3055+MJ2955

The 40W Amp OCL 2N3055+MJ2955 is easy to build, and very inexpensive.
To use Power Supply +35V -35V >2A.
Transistor 2N3055+MJ2955 must be mounted on heatsink.
Can be directly connected to CD players, tuners and tape recorders.

View Circuit and PCB 40W Amp OCL 2N3055+MJ2955

35W Amplifier BCL by TDA2030

The 35W Amplifier BCL by TDA2030 is easy to build, and very inexpensive,Easy to build.
To use Power Supply +15V -15V >2A.
IC TDA2030 must be mounted on heatsink.
Can be directly connected to CD players, tuners and tape recorders.

View Circuit and PCB 35W Amplifier BCL by TDA2030


30W Amp OTL by TDA2030 +Transistor

The 30W Amp OTL by TDA2030 +Transistor is easy to build, and very inexpensive.
To use Power Supply 24V >2A.
IC TDA2030 and Transistor :BD908, BD907 must be mounted on heatsink.
Can be directly connected to CD players, tuners and tape recorders.

View Circuit and PCB 30W Amp OTL by TDA2030 +Transistor

Monday, May 7, 2007

VMOS 10 Watt Amplifier

Read More and View Circuit
VMOS 10 Watt Amplifier

Treble Booster By 741

Read More and View Circuit
Treble Booster By 741

TIP41+TIP42 Cassette Radio Booster

Read More and View Circuit
TIP41+TIP42 Cassette Radio Booster

Telephone Amplifier by LF351+TBA820M

Read More and View Circuit
Telephone Amplifier by LF351+TBA820M

TDA2030 Genneral Purpose Amplifier

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TDA2030 Genneral Purpose Amplifier

Simple Preamplifier by Transistor

Read More and view
Simple Preamplifier by Transistor

Simple Amplifier by Transistor

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Simple Amplifier by Transistor

Headphone Amplifier by Transistor

Read More and View circuit
Headphone Amplifier by Transistor

Class A Amplifier by Transistor

Read More and View circuit Class A Amplifier by Transistor

Cassette Preamp by transister

Read MORE and VIEW circuit Cassette Preamp by transister

Active Tone Controls by Transistor

Read More and View circuit Active Tone Controls by Transistor

AC176+AC126 Power Amplifier

Read more and view circuit AC176+AC126 Power Amplifier

Thursday, May 3, 2007

5 Transister (C945) tone control mono.

This circuit Tone Control Mono, 4 Transister : C945 = 5 part.
Supply Volt min 12V 80ma.
Easy to build, PCB small.

circuit 5 Transister (C945) tone control mono.

PCB 5 Transister (C945) tone control mono.

4 Transister (C945) tone control mono.

This circuit Tone Control Mono, 4 Transister : C945 = 4 part.
Supply Volt min 12V 80ma.
Easy to build, PCB small.

circuit 4 Transister (C945) tone control mono.
PCB 4 Transister (C945) tone control mono.

3 Transister (C945) tone control mono.

This circuit Tone Control Mono, 3 Transister : C945 = 3 part.
Supply Volt min 12V <80mA .
Easy to build, PCB small.

Circuit 3 Transister (C945) tone control mono.
PCB 3 Transister (C945) tone control mono.

2 Transister (C945) tone control Stereo.

This circuit Tone Control Stereo, 2 Transister : C945 = 2 part.
Supply Volt min 12V <80mA .
Easy to build, PCB small.
Circuit 2 Transister (C945) tone control Stereo.

PCB 2 Transister (C945) tone control Stereo.

2 Transister (C945) tone control mono.

This circuit Tone Control Mono, 2 Transister : C945 = 2 part.
Supply Volt min 12V <50mA .
Easy to build, PCB small.
Circuit 2 Transister tone control mono.
PCB 2 Transister tone control mono.

Tone control circuits

Tone control circuits are electronic circuits used to modify an audio signal before it is fed to speakers, headphones or recording devices by way of an amplifier. They are akin to and sometimes called filters. In their most basic form, they elevate or attenuate the high and low frequencies of the signal. This is called treble or bass boost or cut, respectively, in the vernacular of audio engineering. More elaborate tone control circuits can elevate or attenuate the middle range of frequencies too. Really elaborate tone controls provide elevation or attenuation in 1/3 octave bands spanning from approximately 30 Hz to 18 kHz. These units are called graphic equalizers because their controls are in the form of sliders that are arranged so as to graphically display the amount of boost or cut being applied at any frequency of interest. The most elaborate units can control not only the boost and cut but also the frequency at which the boost and cut takes place and the bandwidth of the control's action. These are called parametric equalizers because they control all of the equalization parameters.

Read More : Tone control circuits

Wednesday, May 2, 2007

Pre MIC 3 Transister ( C945 ) mono

This circuit Dynamic Microphone Preamp,Pre MIC 3 Transister mono.
By Transister Part C945= 3 part.(TR1-TR3) OR C828 OR C458
Supply Volt 12V - 24V.
Easy to build and low cost.
Circuit Pre MIC - 3 Transister (C945) mono
PCB Pre MIC - 3 Transister (C945) mono

Pre MIC - 3 Transister (C945) mono

This circuit Dynamic Microphone Preamp,Pre MIC 3 Transister mono.
By Transister Part C945= 3 part.(TR1-TR3) OR C828 OR C458
Supply Volt 12V - 24V.
Easy to build and low cost.

Circuit Pre MIC - 3 Transister (C945) mono PCB Pre MIC - 3 Transister (C945) mono

Saturday, April 28, 2007

Dynamic Microphone Preamp


Circuit : Andy Collinson
Email: anc@mitedu.freeserve.co.uk

Description:
A low noise pre-amplifier suitable for amplifying dynamic microphones with 200 to 600 ohm output impedance.

Notes:
This is a 3 stage discrete amplifier with gain control. Alternative transistors such as BC109C, BC548, BC549, BC549C may be used with little change in performance. The first stage built around Q1 operates in common base configuration. This is unusuable in audio stages, but in this case, it allows Q1 to operate at low noise levels and improves overall signal to noise ratio. Q2 and Q3 form a direct coupled amplifier, similar to my earlier mic preamp.

Source: http://www.mitedu.freeserve.co.uk/Circuits/Audio/dyn_mic/dyn_mic.htm

15 Watt Amplifier

Circuit : Sergio Garcํa de Alba Garcin from Guadalajara, Mexico
Email: turboman80@hotmail.com

Description:
A 15 watt amplifier made using discrete components. Sergio designed this circuit for his Electronics Level II course.

Source:http://www.mitedu.freeserve.co.uk/Circuits/Audio/amp15.htm

Hi-Fi Preamplifier (transister)

Design: Graham Maynard
Email graham.maynard1@virgin.net

Notes:
This circuit was submitted by Graham Maynard from Newtownabbey, Northern Ireland. It has an exceptionally fast high frequency response, as demonstrated by applying an 100kHz squarewave to the input. All graphs were produced using Tina Pro.

Source :http://www.mitedu.freeserve.co.uk/Circuits/Audio/gmpre.htm

Pre Tone Control Circuit (Transistor)

Notes:
Based on the classic Baxendall tone control circuit, this provides a maximum cut and boost of around 10dB at 10K and 50Hz. As the controls are passive, the last transistor provides a slight boost. The output is designed to feed an amplifier with input impedance of 10k to 250k. Both tone controls should be linear potentiometers.
Source : http://www.mitedu.freeserve.co.uk/Circuits/Audio/t-ctrl.htm

Thursday, April 19, 2007

Motorola Hi-Fi power amplifier




This is a very simple, low cost, Hi-Fi quality power amplifier. You can build it 5 ways, like it�s shown in the table (from 20 W to 80 W RMS).

Some comments:
- The first thing that you must do, is to measure the end transistors (T3 and T4) amplifying coefficient, the hfe or β. If their disagreement is bigger than 30 %, the amplifier would not give a clear sound. I used MJ3001 and MJ2501 transistors, and this disagreement was around 5%.
- Before the first �turning on� you must short circuit the inputs of the amp, and put a mA-meter on the output, than turn the amplifier on, and tune the R13 pot, to decrease the DC current on the output, to some uA-s, or in a lucky situation to zero. I was able to decrease it to 10 uA.

60W Linear amplifier



The 60 Watt linear amplifier is simple all solid state circuit using power mosfet IRF840. The IRF series of power transistors are available in various voltage and power ratings. A single IRF840 can handle maximum power output of 125 watts. Since these transistors are used in inverters and smps they are easily available for around Rs: 20/-.

The IRF linear amplifier can be connected to the out put of popular VWN-QRP to get an output of 60 Watts. The circuit draws 700 ma at 60 Volt Vcc. Good heat sink is a must for the power transistor.

Alignment of the circuit is very easy. Connect a dummy load to the out put of the circuit. You can use some small bulb like 24V 6Watts as the dummy load. I have even used 230V 60Watts bulb as dummy load with my IRF840 power amplifier working at 120Volts. Adjust the 10K preset to get around 100 ma Drain current. I used gate voltage of 0.8V with my linear amplifier. A heigh gate voltage can make the power transistor get distroyed by self oscillation. So gate voltage must be below 2V and fixing at 1V will be safe.

Bifalar transformaer T1 is wound with 8 turns 26SWG on 1.4 x 1 balun core.
The coil on the drain of IRF is 3 turns 20 SWG wound on 4 number of T13.9 torroids (two torroids are stacked to form a balun core). The RFC at the Vcc line is 20 Turns 20 SWG wound on T20 torroid.

2N3055 Power Amplifier


Simple and low cost. The optimal supply voltage is around 50V, but this amp work from 30 to 60V. The maximal input voltage is around 0.8 - 1V. As you can see, in this design the components have a big tolerance, so you can build it almost of the components, which you find at home. The and transistors can be any NPN type power transistor, but do not use Darlington types... The output power is around 60W.

Some comments:
- capacitor C1 regulates the low frequencies (bass), as the capacitance grows, the low frequncies are getting louder.
- capacitor C2 regulates the higher frequencies (treble), as the capacitance grows, the higher frequencies are getting quiter.
- this is a class B amplifier, this means, that a current must flow through the end transistors, even if there is no signal on the input. This current can be regulated with the 500Ω trimmer resistor. As this current incrases, the sound of the amplifier gets better, but the end transistors are more heating. But if this current decrases, the transistors are not heating so much, but the sound gets worse...


copy from : http://www.electronics-lab.com/projects/audio/042/index.html

thank you.


Thursday, March 8, 2007

18W Audio Amplifier

source: RED Free Circuit Designs

-- High Quality very simple unit
-- No need for a preamplifier


Circuit diagram:













Amplifier parts:

P1 = 22K Log.Potentiometer (Dual-gang for stereo)
R1 = 1K 1/4W Resistor
R2 = 4K7 1/4W Resistor
R3 = 100R 1/4W Resistor
R4 = 4K7 1/4W Resistor
R5 = 82K 1/4W Resistor
R6 = 10R 1/2W Resistor
R7 = R22 4W Resistor (wirewound)
R8 = 1K 1/2W Trimmer Cermet (optional)


C1 = 470nF 63V Polyester Capacitor
C2,C5 = 100΅F 3V Tantalum bead Capacitors
C3,C4 = 470΅F 25V Electrolytic Capacitors
C6 = 100nF 63V Polyester Capacitor
D1 = 1N4148 75V 150mA Diode
IC1 = TLE2141C Low noise,high voltage,high slew-rate Op-amp
Q1 = BC182 50V 100mA NPN Transistor
Q2 = BC212 50V 100mA PNP Transistor
Q3 = TIP42A 60V 6A PNP Transistor
Q4 = TIP41A 60V 6A NPN Transistor
J1 RCA audio input socket



Power supply parts:

R9 = 2K2 1/4W Resistor
C7,C8 = 4700΅F 25V Electrolytic Capacitors
D2 100V 4A Diode bridge
D3 5mm. Red LED
T1 220V Primary, 15 + 15V Secondary 50VA Mains transformer
PL1 Male Mains plug
SW1 SPST Mains switch


Notes:

  • Can be directly connected to CD players, tuners and tape recorders.

  • Don't exceed 23 + 23V supply.

  • Q3 and Q4 must be mounted on heatsink.

  • D1 must be in thermal contact with Q1.

  • Quiescent current (best measured with an Avo-meter in series with Q3 Emitter) is not critical.

  • Adjust R3 to read a current between 20 to 30 mA with no input signal.

  • To facilitate current setting add R8 (optional).

  • A correct grounding is very important to eliminate hum and ground loops. Connect in the same point the ground sides of J1, P1, C2, C3 &C4. Connect C6 at the output ground.

  • Then connect separately the input and output grounds at the power supply ground.


Technical data:

Output power: 18 Watt RMS @ 8 Ohm (1KHz sinewave)

Sensitivity: 150mV input for 18W output

Frequency response: 30Hz to 20KHz -1dB

Total harmonic distortion @ 1KHz: 0.1W 0.02% 1W 0.01% 5W 0.01% 10W 0.03%
Total harmonic distortion @10KHz: 0.1W 0.04% 1W 0.05% 5W 0.06% 10W 0.15%

Unconditionally stable on capacitive loads

from:: http://www.electronics-lab.com/projects/audio/012/index.html