Showing posts with label car. Show all posts
Showing posts with label car. Show all posts

Saturday, November 8, 2014

Car Battery 12v Charger

The usual chargers of battery automotive, are simple and cheap appliances that charge continuously the battery, with a rythm of few amperes, for the time where the appliance is ON. If the holder do not close in time the charger, the battery will overcharge and her electrolytic faculty are lost with evaporation or likely exists destruction of her elements. The charger of circuit exceeds these faults. It checks electronic the situation of charge of battery and it has circuit of control with retroaction, that forces the battery charge with biggest rythm until charge completely.
Circuit diagram:

Car Battery 12v Charger Circuit Diaram
When charge completely, it turns on one RED led (LD2). The charger has been drawn in order to charge batteries of 12V, ONLY. What should watch it from what it manufactures the circuit, they are the cables that connect the transformer with the circuit and in the continuity the battery, should they are big cross-section, so that heat when it passes from in them the current of charge and also they do not cause fall of voltage at the way of current through them.
Adjustment
After assembling of the circuit, adjust TR1 to null value, power-up and make the following adjustments :-
  1. Without connecting the battery check that the 2 LED?s are turned on.
  2. Connect a car battery to the circuit and check that LD2 is OFF and a current (normally 2A to 4A) is flowing to the battery.
  3. Adjust TR1 until LD2 turns ON and the charge current is cut.
  4. Adjust TR1 to null value and charge the battery using the hydrometer technique (if you do not have or do not know how to use a hydrometer, then use a good condition battery and charge).

Carefully adjust TR1 so that LD2 begins to turn ON and the charge current falls to a few hundred milliamps (mA). If TR1 is set correctly then in the next round of charging you will noticed LD2 begin to flicker as the battery is being charged. When battery is completely charged, LD2 turns ON completely.TR1 does not need further adjustment anymore. Q1 is connected in line with the battery and is fired by R3, R4 and LD2. The R2, C1, TR1 and D2 sense the voltage of the battery terminal and activate Q2 when the voltage of the battery terminal exceeds the value predetermined by TR1.

When an uncharged battery is connected, the terminal voltage is low. Under this circumstance, Q2 is turned OFF and Q1 is fired in each half cycle by R3, R4 and LD2. The Q1 functions as a simple rectifier and charges the battery. If the battery terminal voltage is increased above the level that had been fixed by TR1, then Q2 shifts the control of Q1 gate. This deactivates Q1 and cuts off the current supply to the battery and turns LD2 ON indicating that the charge has been completed. Q1 and bridge rectifier GR1 should be mounted on heatsinks to prevent overheating. M1 is a 5A DC ammeter to measure the charge current
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Thursday, October 16, 2014

Simple Car Alarm Arming Horn Beep Canceller

Its a great convenience that most modern cars come with a built in alarm, however it is nothing but noise pollution that the horn sounds when the alarm is armed. Disconnecting the alarm system from the horn relay will eliminate this, but prevent the horn from sounding in the even of an actual alarm. This circuit serves to silence the arming beep yet maintain the alarm by introducing a small delay into the signal. It sits between the alarm and horn relay. The alarm must provide a constant horn signal for at least 3 seconds before the horn relay is activated. That way the quick "beep" will never activate the horn relay, while the constant alarm signal will. 



Part
Total Qty.
Description
Substitutions
C110.01uF Ceramic Disc Capacitor
C21100uF 35V Electrolytic Capacitor
R111K 1/4W Resistor
R2110K 1/4W Resistor
R3115K 1/4W Resistor
R41470 Ohm 1/4W Resistor
D1, D3, D431N4004 Rectifier Diode
D21Red LED
U11555 Timer IC
K11SPST 12V Automotive Relay
MISC1Board, Wire, Socket For U1, Case
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Tuesday, September 9, 2014

Sound in the car

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.
Original article source cxem.net
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Saturday, September 6, 2014

50W car audio amplifier schematic circuits

50WCar power amplifier uses SI1050GL IC as the main amplifier. The output power 50 Watt 8 ohm mono impedance. Up to 25 Volt DC voltage. with source voltage of this amplifier car battery has to work.

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Simple Low Power Car Stereo Amplifier

A simple low power car stereo amplifier schema based on TDA 2003 is shown here. The schema uses cheap, readily available components and it is very easy to construct. TDA2003 is an integrated car radio amplifier from ST Micro electronics that has a lot of good features like short schema protection for all pins, thermal over range low harmonic distortion, low cross over distortion etc. 

Circuit diagram :

 A simple low power car stereo amplifier Circuit Diagram


In the schema given here each TDA2003 is wired as a mono amplifier operating from a 12V supply. Resistors R2 and R3 forms a feedback network that sets the amplifiers gain. C7 is the input DC de-coupling capacitor and C5 couples the speaker to the amplifiers output. C4 is used for improving the ripple rejection while C1 and C2 are employed for power supply filtering. C3 and R1 are used for setting the upper frequency cut-off. Network comprising of C6 and R4 is used for frequency stabilization and to prevent oscillation.

Notes.

  • Assemble the schema on a good quality PCB.
  • Heat sinks are necessary for both ICs.
  • The schema can be operated from 12V DC.
  • S1 is the ON/OFF switch

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Sunday, August 31, 2014

20W BRIDGE AMPLIFIER FOR CAR RADIO

Features:

  • COMPACT HEPTAWATT PACKAGE
  • FEW EXTERNAL COMPONENTS
  • OUTPUT PROTECTED AGAINST SHORT
  • CIRCUITS TO GROUND AND ACROSS LOAD
  • DUMP TRANSIENT
  • THERMAL SHUTDOWN
  • LOUDSPEAKERPROTECTION
  • HIGH CURRENT CAPABILITY
  • LOW DISTORTION/LOW NOISE
Circuit Diagram:
20W BRIDGE AMPLIFIER FOR CAR RADIO

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Monday, August 25, 2014

14 Watt car audio amplifier circuit

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.
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Saturday, August 16, 2014

Car Head Lights Turn Off Wiring diagram Schematic

This schema when setup in a car automatically turns off the head light after a preset time after the ignition switch is turned off.So you can walk out easily from the dark garage in the light of your car.

Circuit diagram :
automatic-head-light-turn-off Circuit Diagram
Car Head Lights Turn Off  Circuit Diagram
When the ignition switched on first the voltage from battery is fed to the relay through diode D1.When the ignition switch is turned off it produces a negative going pulse at the pin 2 that triggers the timer. The output of the IC goes high for the time set by R1  .This makes the transistor Q1 to conduct to energize the relay to drive the headlight.After the set time the light goes off.With the value of components used you can make a setting from 10 S to 60 S.
Notes :
  • Assemble the schema on a good quality PCB or common board.
  • Fit the potentiometer on somewhere on the dashboard so that  you can easily set the timing.


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