Showing posts with label 5. Show all posts
Showing posts with label 5. Show all posts

Thursday, October 9, 2014

Improved 240 VAC TO 5 VDC 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.


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Monday, September 8, 2014

Transformerless 5 Volt Power Supply Wiring diagram Schematic

Description

An increasing number of appliances draw a very small current from the power supply. If you need to design a mains powered device, you could generally choose between a linear and a switch-mode power supply. However, what if the appliance’s total power consumption is very small? Transformer-based power supplies are bulky, while the switchers are generally made to provide greater current output, with a significant increase in complexity, problems involving PCB layout and, inherently, reduced reliability. 

Is it possible to create a simple, minimum part-count mains (230 VAC primary) power supply, without transformers or coils, capable of delivering about 100 mA at, say, 5 V A general approach could be to employ a highly inefficient stabilizer that would rectify AC and, utilizing a zener diode to provide a 5.1 V output, dissipate all the excess from 5.1 V to (230×v2) volts in a resistor. Even if the load would require only about 10 mA, the loss would be approximately 3 watts, so a significant heat dissipation would occur even for such a small power consumption. 

At 100 mA, the useless dissipation would go over 30 W, making this scheme completely unacceptable. Power conversion efficiency is not a major consideration here; instead, the basic problem is how to reduce heavy dissipation and protect the components from burning out. The schema shown here is one of the simplest ways to achieve the above goals in practice. A JVR varistor is used for overvoltage/surge protection. Voltage divider R1-R2 follows the rectified 230 V and, when it is high enough, T1 turns on and T3 cannot conduct.

Circuit diagram:

Transformerless


When the rectified voltage drops, T1 turns off and T3 starts to conduct current into the reservoir capacitor C1. The interception point (the moment when T1 turns off) is set by P1 (usually set to about 3k3), which controls the total output current capacity of the power supply: reducing P1 makes T1 react later, stopping T3 later, so more current is supplied, but with increased heat dissipation. Components T2, R3 and C2 form a typical ‘soft start’ schema to reduce current spikes this is necessary in order to limit C1’s charging current when the power supply is initially turned on. At a given setting of P1, the output current through R5 is constant. 

Thus, load R4 takes as much current as it requires, while the rest goes through a zener diode, D5. Knowing the maximum current drawn by the load allows adjusting P1 to such a value as to provide a total current through R5 just 5 to 6 mA over the maximum required by the load. In this way, unnecessary dissipation is much reduced, with zener stabilization function preserved. Zener diode D5 also protects C1 from over voltages, thus enabling te use of low-cost 16 V electrolytics. 

The current flow through R5 and D5, even when the load is disconnected, prevents T3’s gate-source voltage from rising too much and causing damage to device. In addition, T1 need not be a high-voltage transistor, but its current gain should exceed 120 (e.g. BC546B, or even BC547C can be used).

CAUTION!

The schema is not galvanically isolated from the mains. Touching any part of the schema (or any schemary it supplies power to) while in operation, is dangerous and can result in an electric shock! This schema should not be built or used by individuals without proper knowledge of mains voltage procedures.




Copyright: Elektor Electronics Magazine
Author: Srdjan Jankovic & Branko Milovanovic
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Monday, September 1, 2014

KA2211 5 8W Stereo Audio Amplifier

The following schematic is the diagram of 5.8 stereo power amplifier based on Samsung IC KA2211. The 5.8W is the power output on each channel, it means that the output will be 2 x 5.8W (maximum).

KA2211,



About KA2211:
KA2211 is a dual audio power amplifier for consumer application. It is designed for high power, low dissipation dan low noise. Is also contains various of protectors and suitable for high performance car audio power amplifier.

Download the datasheet document of KA2211 HERE

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Sunday, August 31, 2014

Making Home Theater 5 1 Surround Amplifier

5.1
Actually, 5.1 channel amplifier consists of 6 amplifiers 1 channel mono, which has certain specifications on each canals. Has 6 channel surround sound amplifier that consists of Front Left | Center | Front Right | Rear Left (Left Surround) | Rear Right (Right Surround) | and LFE (Subwoofer).


For clarity I give a simple illustration of the layout and the circuit for these speakers.


5.1
5.1 Speaker Setup

Accoustic Field Generator

Acoustic Field Generator is generating acoustic sound with surround effects are adjustable with a standard Dolby Surround, able to produce surround sound is good enough but not too much need of funds. Technological developments as if not only focused on one area alone but on all fronts. The development of technologies that exist today one of them is in the field of audio. With more advanced audio technology today not only as mere entertainment but has become a hobby, hobby is not cheap of course. Many audio enthusiasts trying to make music sound that sounded to be very hard to make music sound as live, the addition of the amplifier, woofer or special speakers that cost is not cheap.

The sound effects are living seems to now is something that most do not have to exist in every good audio devices. This effect is basically a surround effect that can lead to sound as though coming from different directions and his voice can still be heard clearly. Currently Compo-tape tape that has been a lot of these facilities surround sound but not good enough when heard from a considerable distance because of the effects surroundnya missing. This is because the distance is too far listener and speaker, speaker layout is not quite right, or the effect of unfavorable surround.

Surround effects are nice and can be heard with a good surround system is a system that is in movie theaters and to make it not a bit prangkat needed funds. However, if satisfaction remains the number one then the fund is not a major problem. To find a middle ground between price and quality surround effects it was attempted to make the Acoustic Field Generator that can produce surround sound is good enough but not too much need of funds. Acoustic Field Generator is capable of generating acoustic sound with surround effects are adjustable with a standard Dolby Surround.

Accoustic Field Generator Construction


Basically an Acoustic Field Generator built from op-amp circuit and filters. Op-amps are usually used as a voltage amplifier in the Acoustic Field Generator is more widely used as active filters. The filter in the tool is very instrumental in creating an acoustic sound that is really clear, but in practice, almost all the filters, do not miss the precision of the signal with a specific frequency. An op-amp is good for this application is the op-amp which has a wide bandwidth, rise time, slew rate and fast setting timenya. In addition to op-amp and active filter, theres more important parts of the power supply. This is the part that is instrumental in creating excellence acoustic sound because of the bad power supply which is the only producer of noise, which will enter into a voice signal path so that should clear acoustic sound into an acoustic sound with the addition of reverberation (noise). The power supply used is the twin power supply + / - 18 volts DC. Part Acoustic Field Generators

Before we start doing this project, it helps us know in advance about the function of each speaker.

Front Channel

Channel Front is a forward channel input signal LR. LR signal is passed to an amplifier with gain = 1 so that this signal is passed without change / to filter the input signal LR. Front Left and Front Right, is a public speaker that we encountered in stereo amplifier, consisting of a woofer and tweeter. Woofers generally produce low tone sound with a frequency range ranging from 80Hz - 250Hz, while the tweeter produces a high tone with a frequency range between 15kHz - 20kHz. For projects that we will create, its good we use a good quality woofer, with a size of 10 inches and a type piezoelectric tweeter for each speaker fronts.

Front
Front Channel 5.1 Amplifier

Center Channel

Center, the fullrange speakers, which produce sound with a frequency range between 80Hz - 10Khz. Output from the center speaker is a summation of left and right signal (left + right = center). In a movie or song Dolby Surround format, commonly used center for dialogue / vocal or speech of the actor / artist of a film and to produce a sound that moves ahead of us.

Center
Center Channel 5.1 Amplifier


Rear Channel with Surround System

In this section is the core of this hard perangakat. These sections produce surround effects. To produce the surround effect is required special IC MN3005 / 8 and MN3101. Both these ICs will delay the incoming signal in several phases, so that the signal output from this phase will be left with a signal phase of the signal lain.Pada this section L and R are deducted (LR) and then passed in the buffer, filter LPF, delay line, filter LPF (7KHz) and the last is a splitter between the signals R and L. Circuit which causes the surround effect is 75KHz LPF circuit that produces its output fed to the Right Rear 75KHz LPF amplifier input while it diparalel with the Left Rear amplifier input so as to produce two signals L and R which is basically a LR signal a phase lag with the original signal phase.

Rear Left and Rear Right, also known as surround speakers. This speaker is generally a semi-midrange speaker (usually used on television or Mini Compo), commonly called satellite speakers. In a movie surround speakers are used to generate the audible sound of distant voices or sounds that move from the back of our approach. In a music surround speakers produce sound backing vocals and generally sounds like guitars, violins and trumpets sounded clear here.

Rear
Rear Channel 5.1 Amplifier

Subwoofer Channel

Part of this subwoofer is the summation of inputs L and R inputs to a summing amplifier. The output of the summing amplifier is passed to a class 2A LPF which will only pass signals with frequency rendah.Subwoofer, sometimes referred to as LFE (Low Frequency Effect). For these speakers using a subwoofer speaker. Speaker woofer speaker subwoofer is designed specifically to be able to respond to sound with a very low frequency, ranging from 15Hz - 120Hz. For low tone effect can be produced by either (without any harmonic frequency), then the acoustic box / box speakers are also designed specifically with a variety of methods (there are no visible speaker / inside the box, there are that use insulation / labyrinth, etc. ), so that the speaker is capable of compressing the air effectively, so that will feel the effect.

Subwoofer
Subwoofer Channel 5.1 Amplifier


Wiring
Wiring Diagram Home Theater Amplifier / 5.1 Amplifier

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