Free Electronic Circuit Design

Electronics Circuits - Blazer Power Amplifier using Transistors 8 (4 sets) on the Sanken final will guarantee that the energy generated is enormous.

You can connect the output to the speakers as large as 18 "or 21" which in parallel as much as 2 pieces (4 ohm impedance).

His bass voice boomed though will be outdoors.

This power amplifier is very appropriate for those of you who really want to improve the sound quality of the sound system rentals.

Blazer in the design for the use of a sound system in a field that requires the beat at low frequencies.

With these Power Blazer, low tone (bass) that are produced will be deeper and kicking.

But must be supported by an appropriate speaker and the right speaker Box in the application.

For the use of the scale House (Home Audio) we do not recommend this Power Amplifier.

But to generate tone Mid or Mid High, little Blazer have a weakness at this point.

The Mid tone is generated less subtle or less detail.

So to your sound system, we recommend using the Power Blazer is only for Low-end Amplifier only.

There is one more thing you need to consider before you assemble the Blazer that the Power Amplifier is in dire need of a large flow of suply.

For the module X-8 Mono only, you need at least 20 Ampere Current Suply/45VAC.

To get more power, the AC voltage should be higher than that which is around 55-60 VAC.

SPECIFICATIONS

Block Diagram:

Here, it is a diagram of an active loudspeaker. The LF353 of, National Semiconductor, is going to split audio signal into three bands. SANYO'S LA47536 is going to amplify these signals. In stereo mode, we shall have the action of eight high speakers who are going to create a very important sound pressure.

Three Band Active Tone Control:

Description :

LF353 Wide Bandwidth Dual JFET Input Operational Amplifier.

General Description

These devices are low cost, high speed, dual JFET input operational amplifiers with an internally trimmed input offset voltage (BI-FET II technology). They require low supply current yet maintain a large gain band width product and fast slew rate.

In addition, well matched high voltage JFET input devices provide very low input bias and offset currents.

The LF353 is pin compatible with the standard LM1558 allowing designers to immediately upgrade e the overall performance of existing LM1558 and LM358 designs.

These amplifiers may be used in applications such as high speed integrators, fast D/A converters, sample and hold circuits and many other circuits requiring low input offset voltage, low input bias current, high input impedance, high slew rate and wide bandwidth.

The devices also exhibit low noise and offset voltage drift. (National Semiconductor)

Features :

Internally trimmed offset voltage: 10 mV

Low input bias current: 50pA

Low input noise voltage: 25 nV

Low input noise current: 0.01 pA

Wide gain bandwidth: 4 MHz

High slew rate: 13 V/us

Low supply current: 3.6 m

High input impedance: 1012.

Low total harmonic distortion : < 0.02%

Low 1/f noise corner: 50 Hz

Fast settling time to 0.01%: 2 us

Power Amplifier :

When the amplifier is installed behind in the suitcase, we shall need a switch works stop.

The LA47536 possesses a function stand by in it pin4.

This pine require a small tension superior to 2V in start up the amplifier.

Transistor Q1 and Q2 makes the function of walking stop for distance.

When the driver activates the left indicator, either light the back fires or press on the brake , lamps rear ignite driving Q2 who he even made to drive Q1 who applies a tension > 2V on it pin4.

LA47536 Four-Channel 45 W BTL Car Audio Power Amplifier

The LA47536 is a 4-channel BTL power amplifier IC developed for use in car audio systems. The output stage features.

- A pure complimentary structure that uses V-PNP transistors on the high side and NPN transistors on the low side to provide high power and superb audio quality.

- The LA47536 includes almost all the functions required for car audio use, including a standby switch, a muting function, and each protection circuit. It also provides a self-diagnosis function (output offset detection). (Sanyo)

Functional Description

1. Standby Switch Function (pin 4)

The pin 4 threshold voltage is set to be 2 VBE. When Vst is 2.0V or higher, the amplifier will be on, and when Vst, is 0.7V or lower, the amplifier will be off. Note that pin 4 requires an operating current of at least 40uA.

2. Muting Function

The IC is set to the muted state by setting pin 22 to the ground potential. In this state, the audio output is muted. The time constant with which the muting function operates is set by an external RC circuit, and this time constant influences the pop noise that occurs when the amplifier is turned on or off.

The muting on and off times due to the recommended external component values (R=10k, C=3.3uF) are as follows.

Muting on time: 50ms

Muting off time: 20ms

3. Self-Diagnosis Function (Speaker burnout prevention)

During steady state operation, the LA47536 detects, internally, whether or not an abnormal amplifier output offset has occurred, and outputs this signal from pin 25. Applications can prevent speaker burnout and other problems by having the system microcontroller detect this pin 25 output signal and control either the standby state or the power supply. (An abnormal output offset may be caused by, for example, input capacitor leakage current.) The pin 25 signal is turned off by setting pin 1 to the ground potential.

4. Oscillator Stability

In some cases, parasitic oscillations may be induced by the PCB layout. This oscillation can be eliminated by adding the components listed below. Note that the optimal capacitor value must be verified by testing in the actual mounted state in the end product. Connect a capacitor and resistor (0.1uF and 2.2) in series between each output pin and ground.

5. Audio Quality (Low band)

The frequency characteristics in the low frequencies can be improved by making the capacitance of the input capacitors variable. The recommended capacitance is 2.2uF and smaller.

6. Protection Circuits

Do not ground the outputs with the STBY voltage at around 1.4V. Also, do not turn the IC off in the grounded state with a time constant provided for the STBY voltage.

7. Pop Noise

Although the LA47536 includes an pop noise prevention circuit, pop noise can be reduced even further by using the muting function as well. Activate the muting function at the same time as power is applied. Then, after the output DC potential has stabilized, turn off the muting function. When turning the amplifier off, first turn on the muting function and then turn off the power supply. These two methods are effective at minimizing pop noise.

PCB Layout :

Many people are asking how to estimate power amplifer audio and how to measure it. Power cannot be explained without understanding what that voltage, current, and resistance. Ohm's law States that V = I x R, where V is the voltage, I is the current, and R is the resistance. The unit of voltage is expressed in Volt, the unit of current in Ampere, and a unit of resistance in Ohm. Ohm's law was discovered by Georg Ohm in 1827.

Power itself has a sense of energy that brought about or consumed divided time. This power is expressed in units of Watt. Electrical power is expressed as P = (V x Q)/t. P is the power in Watts of, V is voltage, Q is the electric charge (electric charge) in coulomb and t is time in seconds. The electric charge is split time is the electrical current so that power can be expressed P = V x I. In relation to Ohm's law, power can be expressed as P = V x V/R or P = I x I x r.

Audio signal is the signal back and forth or AC (alternating current ) then the power calculations become more complex. The signal back and forth have a voltage that is constantly changing at any time so that its power is also changing all the time. In order to facilitate the analysis, then we use sine signals.

Average Value

The average value of the signal back and forth is the average value in half a period. For sine signal, the average value is equal to the maximum value is divided (2/π).

Average Power is the energy of the resulting average in one period. The average power is used to calculate the required transistor or cooling estimate an increase in temperature (power dissipation) on electronic components. The average power is expressed as follows: (I ² _Peak x R)/2

The Value Of The Effective

If direct current 1A resulted 100-degree temperatures in a resistance, then alternating current sine-shaped of 1A maximum (peak value) will generate temperatures 70.7 degrees on the same resistances. 70.7/100 or 0.707 is called the value of effective or root mean square (RMS).

The rms voltage of the sine signal = 1/√ 2 of voltage peaks. Current sine signal rms = 1/√ 2 of the current peaks. Power rms = V rms x I rms

Audio Power Amplifier

Specifications of the power amplifier using power RMS audio with sine signal of 1 kHz, 8 Ohm load or at 4 ohms, and Total Harmonic Distortion (THD) maximum of 1%.

To the amplifier is not Bridge Tie Load (BTL), maximum voltage is limited by its power supply voltage and voltage of transistor saturation finale. Whereas the maximum current is limited by the maximum current of the transformer. Of course it should be ascertained transistors work on area Safe Operating Area (SOA).

On the power supply that is not regulated, the greater the currents drawn amplifier, voltage power supply getting down. This is because the power supply has a non-zero output impedance. Generally a good transformer is not experiencing a decrease in voltage is more than 5% when the maximum current encumbered. Not to mention the ripple voltage of power supply the magnitude depends on the magnitude of the capacitance of rectifier diodes after elco. Diode rectifier also reduces the voltage of power supply approximately 1V.

Whereas the saturation voltage transistors can reach large collector current dependent 3V.

Calculation example

For example there is a transformer-32V 5A CT will be used as an audio amplifier. How much is the maximum power estimated at 4 Ohm?

Power supply voltage on the load at the maximum = (peak voltage x 95%) – voltage diodes – voltage ripple.

Peak voltage = 32 x √2 = 45 V (rounded for easy).

Voltage diodes = 1 V Voltage ripple = 3 V Power supply voltage on the load at the maximum = 38,75 V

Maximum signal voltage (peak) = Voltage of power supply at maximum load – transistor saturation voltage = 38.75 – 3 = 35.75 V

RMS power at 4 Ohms = (Signal voltage RMS)²/ R = ( 35.75 / √2 )²/ 4 = 160 W RMS (rounded).

To load the speaker are slightly different from the above calculations, because the speaker impedance is not purely resistive in nature, but rather have inductance as well. So cos φ or power factor needs to be taken into account. However, this will not be discussed here because it is too complicated for beginners.

The Way Of Measurement

The way of the power measurement of audio amplifiers can be described as follows:

In the input amplifier 1 kHz sine signal being given from the signal generator. The output of the amplifier is connected to the dummy load a power resistor whose value is approx. 4 Ohm or 8 Ohm. Make sure that the maximum power of the dummy load greater than maximum power amplifiers. If the voltage peak of the output amplifier is very high, it needs to be lowered with attenuator or voltage divider. Then the signal is inserted into the Distortion Analyzer. Output Distortion Analyzer input to oscilloscope to see the visualization.

Menghitung Dan Mengukur Daya Audio Amplifier

1. Adjust the frequency signal genarator 1 kHz sinus.

2. Adjust the level of the signal voltage generator until THD Analyzer shows a 1% THD.

3. Measure the voltage seen on oscilloscope.

If the measured peak voltage of 20V and on attenuator the voltage is divided 5, then the real peak voltage 20 x 5 or 100V.

RMS Voltage = 1/√2 x 100V = 70,7V rms.

Suppose a dummy load resistance of 4 Ohm, then RMS Power = (70,7 x 70,7) / 4 = 1250 Watt rms.

basic operational amplifier configurations

So to make things a little bit easier for all, here is a list of some of the “Basic Operational Amplifier Building Blocks” we can use to create different electronic circuits and filters.

The Voltage Follower

The Voltage Follower, also called a buffer dose not amplify or invert the input signal but instead provides isolation between two circuits. The input impedance is very high while the output impedance is low avoiding any loading effects within the circuit. As the output is connected back directly to one of the inputs, the overall gain of the buffer is +1 and Vout = Vin.

The Voltage Follower Op-amp Circuit

The Op-amp Inverter

The Inverter, also called an inverting buffer is the opposite to that of the previous voltage follower. The inverter does not amplify if both resistances are equal but does invert the input signal. The input impedance is equal to R and the gain is -1 giving Vout = -Vin.

The Op-amp Inverter Circuit

The Non-inverting Amplifier

The Non-inverting Amplifier does not invert the input signal or produce an inverting signal but instead amplifies it by the ratio of: (RA + RB)/RB or commonly 1+(RA/RB). The input signal is connected to the non-inverting (+) input.

The Non-inverting Op-amp Circuit

The Inverting Amplifier

The Inverting Amplifier both inverts and amplifies the input signal by the ratio of -RA/RB. The gain of the amplifier is controlled by negative feedback using the feedback resistor RA and the input signal is fed to the inverting (–) input.

The Inverting Op-amp Circuit

The Bridge Amplifier

The inverting and non-inverting amplifier circuits from above can be connected together to form a bridge amplifier configuration. The input signal is common to both op-amps with the output voltage signal taken across the load resistor, RL. If the magnitudes of the two gains, A1 and A2 are equal to each other then the output signal will be doubled as it is effectively the combination of the two individual amplifier gains.

The Bridge Op-amp Circuit

The Voltage Adder

The Adder, also called a summing amplifier, produces an inverted output voltage which is proportional to the sum of the input voltages V1 and V2. More inputs can be summed. If the input resistors are equal in value (R1 = R2 = R) then the summed output voltage is as given and the gain is +1. If the input resistors are unequal then the output voltage is a weighted sum and becomes:

Vout = -(V1(RA/R1) + V2(RA/R2) + etc.)

The Voltage Adder Op-amp Circuit

The Voltage Subtractor

The Subtractor also called a differential amplifier, uses both the inverting and non-inverting inputs to produce an output signal which is the difference between the two input voltages V1 and V2 allowing one signal to be subtracted from another. More inputs can be added to be subtracted if required.

If resistances are equal (R = R3 and RA = R4) then the output voltage is as given and the voltage gain is +1. If the input resistance are unequal the circuit becomes a differential amplifier producing a negative output when V1 is higher than V2 and a positive output when V1 is lower than V2.

The Voltage Subtractor Op-amp Circuit

The Op-amp Comparator

The Comparator has many uses but the most common is to compare the input voltage to a reference voltage and switch the output if the input voltage is above the reference voltage. If the input goes more positive than the reference voltage set by the voltage divider, Vin > Vref, the output changes state. When the input voltage drops below the preset reference voltage and Vin < Vref, the output switches back. By using positive feedback the basic comparator circuit can easily be converted into a Schmitt Trigger to reduce oscillations around the switching point.

The Comparator Op-amp Circuit

Here are just some of the more common and basic operational amplifier building block configurations discussed in this section that we can use in electronic circuits. All the above circuits can be constructed using a variety of different op-amps including the famous 741 op-amp. I hope that this short tutorial about basic op-amp building blocks will help you to understand the different basic op-amp circuit configurations.

Download Edison 5 Multimedia Lab for exploring electronics and electricity

Edison version 5 is a unique new learning environment for electricity and electronics. Teachers and students can use multimedia screens, virtual instruments, sound, and animation to create, test, and safely repair circuits. Real-time 3D graphics and lifelike 3D components will captivate your students as they build circuits in the real 3D world. Edison also comes with over 100 experiments and problems that teachers and students can use immediately.

edison5 multi Download Edison 5 Multimedia Lab for exploring electronics and electricity Tutorial transistor Simulator Microcontroller electronic software Download auto

Select realistic batteries, resistors, diodes, LEDs, transistors, logic gates, flip-flops, and even microcontrollers & integrated circuits all easily available on the shelves of your multimedia lab. Drag them onto your “breadboard” and wire them together with your mouse. Your circuit begins working immediately so you can test and troubleshoot it with virtual instruments. In addition, Edison automatically prepares a standard schematic diagram and displays it simultaneously.

Once you have become familiar with schematic diagrams, you can use Edison’s schematic editor and circuit analyzer, compatible with the more advanced TINA circuit analysis program. Edison provides a state of the art analysis results window in addition to its virtual instruments. Using the results window, you can present circuit analyzes with full control over axes, line style, color and fonts. You can even print these diagrams directly from Edison or cut and paste them into your favorite word processor.

One of the most intriguing and innovative features of the new Edison is that it can not only calculate voltages and currents, but also, for linear circuits, show how these results are derived or mathematically described. For example, you can learn how to use Ohm’s law, how the output of a filter varies with frequency, and how the voltage of a charging capacitor varies as a function of time.

Download Edison 5 Multimedia Lab for exploring electronics and electricity

AMPLIFIERS NON-INVERTING AND INVERTING AMPLIFIERS

PDF FILE - CLICK HERE FOR PRINTABLE WORKSHEET

1. An inverting amplifier - Leg two is the input and the output is always reversed or inverted. 2. A Non-inverting amplifier - Leg three is the input and the output is not reversed.

Opposite is a diagram of an INVERTING AMPLIFIER. This means that if the voltage going into the 741 chip is positive, it is negative when it comes out of the 741. In other words it reverses polarity (inverts polarity). Two resistors are needed to make the 741 work as an amplifier, R1 and R2. In most text books diagrams like this are used to represent the 741.

HOW TO CALCULATE THE 'GAIN' An operational amplifiers purpose is to amplify a weak signal and this is called the GAIN.

INVERTING AMPLIFIER GAIN (AV) = -R2 / R1 Example : if R2 is 100 kilo-ohm and R1 is 10 kilo-ohm the gain would be : -100 / 10 = -10 (Gain AV) If the input voltage is 0.5v the output voltage would be : 0.5v X -10 = -5v	NON-INVERTING AMPLIFIER GAIN (AV) = 1+(R2 / R1) Example : if R2 is 1000 kilo-ohm and R1 is 100 kilo-ohm the gain would be : 1+ (1000/100) = 1 + 10 OR GAIN (AV) = 11 If the input voltage is 0.5v the output voltage would be : 0.5 X 11 = 5.5v




The polarity of a signal is reversed at the output, pin six. A negative input becomes a positive output.	A signal applied keeps its polarity at the output, pin six. A positive input remains a positive output.

Buffer Opamp Amplifier

Buffer Opamp Amplifier

A unity gain buffer amplifier is implemented using an opamp in a negative feedback configuration. The output is connected to its inverting input, and the signal source is connected to the non-inverting input. Although its voltage gain is 1 or unity, it has high current gain, high input impedance and low output impedance. It is used to avoid loading of the signal source.

click here to continue