Thursday, 17 November 2016

4440 Double IC Audio Amplifier Circuit In Stereo Mode

7 Comments
La4440 double ic stereo amplifier is very popular now a day. It is widely used, many hi-fi power amplifier system. In a previous post I already share 4440 single ic stereo amplifier circuit. This 4440 amplifier circuit is given total 38 watt rms output that means each output point is give 19 watt rms.  To run this circuit it needs 12 volt 4 amp power supply.

LA 4440 IC - LA4440 Audio Amplifier IC

In this amplifier circuit discharge speed is high and transient stability is more secure. Moreover, starting time in voltage gain is adjusted in this circuit. So this circuit is work very well and give nice amplification.

 Circuit Features:

1)    Small pop noise at the time of power supply ON/OFF and good starting balance
2)  Good ripple rejection
3)  Small residual noise
4)  Low distortion over a wide range from low frequencies to high frequencies

Circuit Diagram:

4440 Double IC Audio Amplifier Circuit In Stereo Mode

Part List:

    1)    R1, R2 – 47k Potentiometer
2)  R3, R4 – 4.7k
3)  R5, R6, R7, R10 – 430 R
4)  R8, R9, R11, R12 – 4.7 R
5)   C1 – 4700 Uf
6)  C2, C7, C4, C12 – 47uF
7)   C3, C5 - .047uF
8)  C6, C11 – 220uF
9)  C8, C9, C13, C14 – 100uF
10)                     C10, C21, C15, C18 – 1000uF
11)                       C20, C19, C17, C16 - 104

Note:

·       Use proper heatsink
·       Connect the heatsink to ground
·       For power up the circuit use purely filtered dc supply
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Sunday, 3 April 2016

Resistor Color Code Calculator - 4 band Resistor Calculator

This is a 4 band resistor calculator. The calculator above will show the value, the tolerance and performs a basic check to confirm if the computed resistance matches one of the EIA standard qualities. Select the initial 3 or 4 groups for 20%, 10% or 5% resistors. Float over the tolerance for min. also, at the max. range values.



RESISTOR COLOR CODE CALCULATOR



Resistor color code calculator, online resistor calculator, Resistor Calculator.
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Tuesday, 4 August 2015

HOW TO REPAIR & REPLAING MOBILE LCD / SAMSUNG E1282T LCD REPAIRING

2 Comments
In this post you are shown how to replace a damage mobile LCD with a new one. This post is showing a Samsung E1282T mobile LCD changing. In our daily life sometimes our mobile LCD are damaged by mishandling or accidentally. Then we are replacing our mobile LCD by the company’s service center or local mobile repairing shop but it is so costly & also lengthy process. I am changing this LCD only 2$/3$. Now we show how to repair or replace the LCD.
 So first we show what’s parts are needed. 

PART LIST –

1)    Samsung E1282T Mobile LCD
2)  A soldering iron
3)  Solder wire & flux
4)  A Screw driver set
5)   A old damage SIM card
Now we are show step by step how to replace the LCD

STEP 1 – 

At first remove battery & screw
SAMSUNG E1282T LCD REPAIRING

 STEP 2 – 

Then open the mobile back side cabinet by using SIM card. After that as shown in picture desolder the microphone connection.


SAMSUNG E1282T LCD REPAIRING

SAMSUNG E1282T LCD REPAIRING



 STEP 3 – 

Then separate the circuit board & cabinet.  


SAMSUNG E1282T LCD REPAIRING


STEP 4 – 

Now open the mobile LCD portion & desolder the LCD ribbon.

SAMSUNG E1282T LCD REPAIRING

SAMSUNG E1282T LCD REPAIRING

SAMSUNG E1282T LCD REPAIRING

STEP 5 – 

After desoldering clean all the soldering pins. Then take the new LCD & show that it has an adhesive portion which is cover using a sticker. 

SAMSUNG E1282T LCD REPAIRING

SAMSUNG E1282T LCD REPAIRING

STEP 6 – 

So first remove the sticker and attach its correct position as shown in figure.

SAMSUNG E1282T LCD soldering technique

SAMSUNG E1282T LCD REPAIRING

STEP7 – 

Now carefully solder all the pins. Then attach the screen with circuit board using its locking system. 
SAMSUNG E1282T LCD REPAIRING

SAMSUNG E1282T LCD Replacing technique

STEP 8 – 

Finally this LCD is replace & now attach all the parts carefully

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Monday, 20 July 2015

5 VOLT 10 AMP VOLTAGE REGULATOR CIRCUIT

This is a simple 5 volt voltage regulator circuit. This circuit is capable to deliver up to 10 ampere current. The input voltage level is 6 volt to 30 volt. Heart of this circuit is LT1038. LT 1038 is a three terminal IC. This IC is packaged in a standard T0-3 power package. Also this IC is fully protected current limiting & thermal shutdown.

CIRCUIT DIAGRAM - 

5 VOLT 10 AMP REGULATOR CIRCUIT  - LT 1038 regulator circuit - 5 volt 10 amp regulator circuit - 10 Amp Positive Adjustable Voltage Regulator

PART LIST –

1)    C1 – 1 uF
2)  C2 – 10 uF
3)  R1 – 121 Ω
4)  R2 – 365 Ω
5)   LT 1038IC

IC IMAGE & PIN OUT - 


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Tuesday, 14 July 2015

DANCING LED CIRCUIT FOR STEREO AMPLIFIER - LED MUSIC LEVEL INDICATOR FOR STEREO APPLICATION

This is a simple stereo system base LED dancing light circuit. If you have any stereo amplifier & want to attach a LED dancing system so this circuit is perfect for you. Basically, the circuit for dancing light is the same as that of a power level indicator, with the difference that it uses LEDs instead of the traditionally used VU meters. Therefore one may also use it as a power level indicator if each LED could be calibrated for a particular db level. This LED indication is however still rare in Commercially available Stereo amplifiers. 

CIRCUIT DIAGRAM - 

DANCING LED CIRCUIT FOR STEREO AMPLIFIER - LED MUSIC LEVEL INDICATOR FOR STEREO APPLICATION


 CIRCUIT DESCRIPTION –

The circuit contains two LM339 ICs and eight LEDs. LM339 is a quad comparator; it consists four comparator in a chip. In this circuit one IC used for left & the other IC used for right Chanel of the stereo. Each comparator has two inputs & one output. The function of the comparator is to compare the input voltage signal with the reference voltage. If input voltage exceeds to reference voltage, output voltage falls down and the corresponding LED stars Glowing. Resistance R3, R4, R5 & R6 provides the reference voltage levels. 

 PART LIST –

1)    R1, R2 – 68k
2)  R3  to R6 – 1k
3)  R7 to R14 - 390Ω
4)  R15 – 12k trimpot
5)   IC – TWO LM339
6)  LEDs – RED & GREEN 8 Pieace

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Friday, 10 July 2015

5 VOLT TRANSFORMER LESS POWER SUPPLY CIRCUIT

This is a 5volt mains operated transformer less power supply circuit. This circuit worked on 220 to 240 volt AC supply only. That type of circuit is very popular now a day’s because it takes very small space & light weight. This circuit you can use to run any 5 volt application circuit.

CIRCUIT DESCRIPTION -

 C1 is used to decrease the voltage level & R1 is used to remove stored power of C1 in switch off time. C2 is used for reducing the ac ripples. R3 is a limiting resistor & Z1 is maintaining the voltage level. This circuit actually giving 12 volt 100ma but using 7805 regulator IC the 12 volts are converting 5volt & its give 240ma current.

CIRCUIT DIAGRAM - 

5 VOLT TRANSFORMER LESS POWER SUPPLY CIRCUIT


 CAUTION –

Shock hazards be careful because the circuit is not isolated 

PART LIST –

1)    R1 – 470k/1W
2)  R2 – 100R/1W
3)  R3 – 220R/1W
4)  R4 – 1k
5)   C1 – 225K/400V PF
6)  C2 – 470uF/200V
7)   Z1 – 15 VOLT/1W
8)  7805 IC – 1 Piece
9)  1 Piece RED LED

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Wednesday, 8 July 2015

6 VOLT TO 12 VOLT OPARATED MOTOR SPEED CONTROLLER CIRCUIT

This is a simple motor speed controller circuit. This circuit operate 6 volt to 12 volt power supply. A slider switch is installed to increase or decrease the motor speed. If the motor loaded the circuit gives automatically more power.


 CIRCUIT DIAGRAM -



PART LIST –

1)    R1, R5 – 680
2)  R2 – 1K
3)  R3 – 330
4)  R4 – 500
5)   R6 – 1
6)  R7 – 2.2K
7)   C1 – 47n
8)  D1 – 1N4148
9)  Q1, Q2 – BC547
10)  Q3 – BC557
11)    Q4 – BC338
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