Showing posts with label Car Audio. Show all posts
Showing posts with label Car Audio. Show all posts


Audio Amplifier for Car Radio TDA7374B

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The TDA7374B is a new technology class AB Audio Dual Bridge Power Amplifier in Multiwatt package designed for car radio applications. Thanks to the fully complementary PNP/NPN output configuration the high power performances of the TDA7374B are obtained without bootstrap capacitors.
Circuit diagram:
Audio Amplifier for Car Radio TDA7374B
Audio Amplifier for Car Radio TDA7374B



30W Power Audio Amplifier Circuit Diagram

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TIP141 si a npn silicon power darling tons designed for complementary use with TIP145, TIP146 and TP147. Can stand up to 125 W at 25°C Case Temperature, 10 A Continuous Collector Currentand has a minimum hFE of 1000 at 4 V, 5 A. This home audio amplifier can output 30W with a +- 32V symmetric power supply. If you want a stereo power amplifier please check out the other schematics.


Circuit diagram:



R1=1KohmR16-17=270ohmD1=9.1V 0.4W zener
R2=47KohmR18=22ohm 1WD2-3=1N4148
R4-5=10KohmR20-21=0.39ohm 4WQ3=MPSA56
R6=5.6KohmTR1=250ohm trimmerQ4=BC547B
R7=10ohmC1=470nF 100V MKTQ5=BC212
R8=47KohmC2=1nF 100V MKTQ6=BC183
R9=560ohmC3=68pF ceramicQ7-8=MPSAO6
R10-11=8.2KohmC4-8=22nF 100V MKTQ9=TIP141
R12-15=120ohmC5-6-7=100nF 100V MKTQ10=TIP146
R13=680ohmC9=47uF 25VF1-2=1.6AT FUSE
R14=330ohmC10-11=220uF 63VAll the resistors is 1/4W 1% except quote differently


200 Watt Stereo Car Amplifier


Circuit Description

IC TA8210AH By using this you can apply a series of audio power amplifier is the car audio system. In general, all the speakers in the car using a subwoofer speaker, and woofer. Because the car is not big room so the sound is being required is not too high. Audio amplifier circuit can work at a minimum voltage 12-volt DC, if supplied under voltage 12-voltamplifier work will be less than the maximum. This amplifier output power up to 200W or 2 x 100W stereo with 8 ohm impedance.

Circuit Diagram

200 Watt Stereo Car Amplifier

Part List :

R1 =1K
R2 =50K trim
R3 =1K
R4 =50K trim
R5 =680R
R6 =680R
R7 =150K
R8 =2R2
R9 =2R2


C1 =1uF
C2 =1uF
C3 =47uF
C4 =47uF
C5 =100n/400V
C6 =220uF
C7 =220uF
C8 =100n/400V
C9 =100n/400V

Intregated Circuit



X2-3=in R
X2-1=in L
X1-1,X1-2=Out R
X1-3,X1-4=Out L


Car audio amplifier with IC TA7203P

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Circuit Diagram

Car audio amplifier with IC TA7203P

Circuit Description

Stereo car power amplfier with TA7203P , is suitable for the room your car , your car it will build an increasingly crowded and felt like using high-class amplifiers and speakers. Simply using this circuit and some speaker subwoofer speakers you can enjoy it.

Technical information :

  • Max voltage = 20 Volt
  • Min voltage = 8 Volt
  • Max output = 2 x 40 Watt
  • RL = 8 Ohm

14 Watt car audio amplifier circuit

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Basic operation of this amplifier is on IC TEA2021 ,

In this circuit minimum require voltage is 4 volts and maximum voltage 25 volts. Power output 14 Watt with 4 Ohm impedance. See this schematic.

Car Amplifier with IC LA4445

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This circuit using IC LA4445 , this is stereo amplifier with power output 2 X 18 Watt, with this circuit you can use to car amplifier or to other elctronics device. Speaker use woofer with impedance 4 Ohm with power up to 20 Watt. Minimum voltagte require 10 Volt and maximum voltage 18 volt.
Car Amplifier with IC LA4445

If you can't operate the circuit , please check IC , and then voltage in. If voltage is good check the component are. If components are working . Please check speakers.



Subwoofer filter LM 741

Description for Subwoofer filter LM 741:
     If you like I want some more bass in your stereo, you can switch a subwoofer there. This is a speaker that only reflects the bass. Below is a circuit to ensure that the subwoofer gets really only the bass. 
This circuit is used between the signal source (mixer, CD player) and the amplifier. It is an active filter, better than passive filters which are generally mounted behind the amplifier. The circuit is mono because the bass for both channels are equal. The human ear can not yet determine the direction of this bass. 
The first 741 is used as a mixer amplifier. The gain is adjustable with P1. Then, the signal is applied to a second of the order Butterworth-filter. C A(C1 + C2) and C B (C3) can be calculate using the following formulas: where F k , the crossover frequency (the frequency at which filter stops the transmission of sound), pi = 3.1416, R = R3 = R4, F k in Hertz, and C. F. As shown, the filter is now set at 240 Hz. , the supply voltage must be symmetrical, + and - 12-15 V. A suitable diet is the Symmetric mini power supply . If you would like a better sound would have you two 741's replaced by an NE5532. The picture for the layout to be printed at 150DPI (= + / - 33x33mm).
Circuit Diagram:
subwoofer filter lm741 circuit diagram

  • R1, R2 = 47 k
  • R3, R4 = 4.7 K?
  • R5, R6 = 100 Ω
  • P1 = 47 k logarithmically
  • C1-C3 = 100 nF
  • IC1, IC2 = LM 741
Layout and PCB:
Subwoofer filter LM741 layout and pcb

Datasheet for LM741 and NE5532:
LM741 Operational Amplifier - Download
NE5532 Operational Amplifier - Download


Separation filter crossover for car subwoofer

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The figure shows a circuit diagram of car crossover (cr
ossover) for the subwoofer. The input stage of the transistor Q1 is a differential summing amplifier, and the switch S1 is used to switch polarity. Switched-capacitor filter with a slope of 24 dB per octave (chip IC1) is the basis of continuously tunable filter. Potentiometer R13 controls the filter cutoff frequency on the chip IC1, adjusting its clock speed. Because the switched-capacitor filters, by definition, work with discrete signals at the input of IC1 should be restrictive filter (antialiasing). Such a low pass filter of the second order constructed by transistors Q2 and Q3 and associated elements. The output signal of IC1 via pin 5 served on a subsonic filter with the possibility of lifting the lowest frequencies. When switch S2 is closed, then on the rise of the frequency characteristic occurs. Additional filtering is provided by infrasound capacitors C1 and C2 directly to the input of the crossover. The resistor R18 and the capacitor C 10 is assembled so-called remodeling filter, eliminating the remnants of the quantization noise. The power supply circuit, gathered on the integral regulator 78L08 (chip IC2), and provides the main supply voltage of 8.6 V, and the bias voltage of 4.8 V. The diode D1 protects the circuit from negative voltage spikes and incorrect wiring. Diode D2 displaces the output reference voltage stabilizer 78L08 0.6 V for receiving an output voltage of 8.6 V, and not B. 8

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Circuit diagram capacitor charge control

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The scheme is designed to protect against inrush current when the battery uncharged capacitor on-board network. Who has not tried to include uncharged faradnik network without limiting resistor - better not ... At a minimum, get burnt contacts.

When you turn the discharged capacity in network capacity C1 is discharged, T1 (n-MOSFET switch with low channel resistance) is closed.Capacitance C2 (the same faradnik) is charged through a low-resistance R5. T2 opens almost instantly, the shunt to ground C1 and T1 gate.When the potential negative terminal C2 falls below 1V (charge to Uakb - 1B), T2 closes smoothly C1 is charged to about 9/10 Uakb opening T1. The time constant R2C1 is large enough so that the current surge T1 (pre-charge C2 +1 V to Uakb) does not exceed the rating for T1.

In the future, the negative terminal of C2 constantly shorted to ground through T1, regardless of the direction CURRENT T1 (both literally - from drain to source, and in the opposite direction). Nothing wrong with "rollover" OPEN TIR transistor not. When choosing a good enough conductive transistor entire reverse current flow through the channel, and a built-wheeling diode will not open because the voltage drop across the channel at times less than required for the opening of 0.5-0.8 V. By the way, there is a whole class of TIR devices (eg FETKY ), designed specifically to work in the opposite direction (synchronous rectifiers), they have built a diode is shunted by an additional force Schottky diode.

Calculation: for transistor IRF1010 (Rds = 0.012 ohms) voltage drop of 0.5 ohms will only be achieved with the current channel 40A (P = 20W).For four of these transistors in parallel and the same discharge current of 40A - on each transistor will dissipate 0,012 * (40/4) ^ 2 = 1.2 W, ieradiators they are not required (the more that will dissipate 1.2W only when differential current consumption but not consistently).

Dense installation (you have plenty of space for extra radiator?) - Advisable parallels small (body TO251, DIP4) transistors, generally do not provide radiators, based on the ratio of current (power) consumption of the amplifier - Rds - limit power dissipation. Since Pds max is typically 1W (800 mW for DIP4), the number of n transistors (c Rds each) for the amplifier with an output power Pout must be at least n> 1/6 * Pout * sqrt (Rds) at 12V supply (dimension in the formula I omitted). In fact, given the short duration current pulses, n can be easily reduced by half compared with a given formula.

Resistor R5 is selected from the charge compromise heat output and charging time. When these 22 ohms - charge time of about 1 minute at power dissipation 7 watts. R5 can instead include 12V bulb, say, indicator. Resistors R1, R3 - reinsurance (discharged capacity when disconnected from the network).

Connect to indicate activation of additional inverter (reducing R2). Attention! The scheme is efficient at using npn transistors T2, T3 with h21e> 200 (KT3102). Depending on the brightness of the LED, R1, select the range of 200 ohms - 1k.

But the view of the circuit in which the key shutter control signal REMOTE (And transistor). The non-connected or off REMOTE key transistor guaranteed closed. D3-D4 LEDs indicate charging C1, D5-D6 - the open state of the key.

Accurate indication of the threshold voltage is provided easiest IP TL431 (KR142EN19) in a typical mode voltage comparator (with the corresponding subgroup in the input circuit and current-limiting circuit cathode R).

Loss schemes largely depend on the installation. Ensure that the minimum resistance (and corresponding current thickness of the wires) in the power circuit (terminal + / C2 / T1 /-terminal). In amateur practice, I think, make outgoing terminals impractical - it is better to unsolder the short wires AWG8, which binds to the terminal block diagram of the amplifier.
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Sound in the car

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It is known that for many motorists machine evolved into something more than just a means of transportation. After all, the person conducting the wheel for several hours a day, not only wants to listen to the local news, but good music. However, high-quality automotive interior equipping reproducing unit, few who can manage only industrial products.
In recent years in the amateur literature appeared many publications devoted to independent manufacturing automotive audio equipment, mainly amplifiers. But even a good amplifier does not solve all the problems faced by the creator of Sound Hi-Fi class for its attitude avtomobilya.Skepticheskoe many motorists to leave such systems due primarily illiterate approach to installing speakers in the cabin.Unfortunately, in most cases, they are placed in the car according to the principle "to fit", not "where it is necessary." However, an unambiguous answer to the question - "Where else do you want?" - Does not exist. None of the known solutions does not give a guaranteed result. Much easier to answer the question "where it is not necessary?". Show rasprstranennaya error - placing powerful and high heads speakers in the rear tray. Front same state that have or nothing. Is the owner of this car prefer to sit with his back to the stage?
Contrary to popular belief, most importantly in the design of the car radio is not to achieve high power, low distortion, and not even getting a good frequency response. The main problem - the creation of a wide soundstage for listeners sitting on the front seat of the car. Its solution is directly related to the installation of the front head.

Under any reasonable version of their placement inside the difference in the signal path from the left and right radiators to the listener reaches unacceptably large. To reduce this difference may be reflected to use all or part of the signal from the windshield. So there setting with outdoor acoustics front (see Fig. 1).

Embodiment of a such a solution is quite difficult and time consuming, but the result is impressive. However, to cut the floor to install the heads dare not everyone. So really to install radiators in front passenger car is not too many places: the dashboard, windshield racks, doors, vertical bar at the bottom of the passenger compartment at the front wheels of the vehicle.

The dashboard allows you to set the emitters at a sufficient height, but head size is usually limited to 10 ... 13 cm, acoustic design is virtually absent, so low frequencies are reproduced in this case efficiently enough. To further advance the sound image can be installed on radiators racks on the side edges of the windshield, but in reality there are only fit tweeter (tweeter).

Popular because of its simplicity and low-frequency coaxial installation heads in the doors usually argued increase efficiency low frequency reproduction ready acoustic design. The result obtained is the opposite desired effect. For the reduction of phonograms most modern tools engineers is situated in the center of the bass sound stage, ie Sound signals of the left and right channels in the same frequency band are in phase and have almost the same intensity. Therefore, when installing radiators in the front door of the sound waves at frequencies 100 ... 150 Hz, critical for the subjective perception of bass attack reaches the opposite head of phase (as determined by the width of the cabin) and compensated. Hence - a dull, lifeless sound that did not fix any EQ. Installation heads in kikpanelyah decreases the difference in the signal path from the left and right radiators, but the sound picture falls unacceptably low. In addition, this embodiment carry the same effect, "blanking" bass attacks, although to a lesser extent as when installing heads in the doors, and organize a decent acoustic design easy.

It follows that the best results can be achieved, the use of multi-band dispersed front speakers. Bandpass emitters should be placed in locations where they will work with maximum efficiency. According to the author the best place to install the bass radiators - in buildings under the front Cedeno with the radiation of sound forward and upward. MF emitters best place on the front panel or in the upper front corner of the door, and HF - racks on the windshield (it picks up sound pattern).

Full bass reproduction is only possible using acoustic design of considerable size, so virtually all car audio sound frequency range is limited to the main channel 100 ... 120 Hz and lower frequencies generated by the speaker as the sum signal. Because at the lowest frequencies loudspeaker has a circular radiation pattern, the choice location for a subwoofer - question komponoki system. Most often, it is placed in the trunk. The problem is that the frequency response of the cabin, which plays here the role of acoustic design, has Wake up in the very low frequencies for each individual model of the body. Therefore, to obtain a uniform frequency response of the total system must be able to adjust only the level but also the frequency response sabfufernom channel.

Sound image formed without using surround izluchatalay certainly be incomplete. Their main value - "the creation of the hall effect" by simulating the reflected sound. Spectrum Signal rear channels (Fig. 2) for this should be limited [2], and the signal can be both traditional ("left-right" channel), and the sum or difference, or a combination thereof. Power rear channel nevilika (no more than 10% of the total capacity of the system), and in some cases, for its realization will require additional amplifying devices. The simplest case - anti-series connection of the rear head between the amplifier output left and right channels through a simple filter.

On the influence of connecting cables and sound quality lately written so much that this subject can not apply here. Wire size than the power supply current consumption and the length of the wires themselves. In any case, the voltage drop in the supply of power at maksimaonoy should be no more than 0.1 ... 0.2 V

Damping parasitic resonances and sound elements salon are also important. Noise absorbing material should be applied to all available panels and plastic body parts, focusing on the panel, located near the head speakers, or those used as part of the speaker enclosure.Resonances usually disappear when the cover 25 percent or more of the area. To absorb road noise noise canceling material should cover polsalona, ​​fireproof bulkhead area and wheels.
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