Resistor color code

A resistor is the most important electrical component in almost every electronic circuit, it can limit current to any load such as led, transistor, opamp, etc. We must read resistor color code if we want to know the resistive value, tolerance, temperature coefficient. Resistors have different color bands (3,4,5,6) the more color bands the more resistor's information.Now let's start with 3 bands resistor color code.

The above resistor has only 3 bands First digit, Second digit, and multiply. A 3 bands resistor color code has fixed +/-20% tolerance that means if color code value is 1,000 ohms the real life resistive value may be +/- 200 ohms. 
4 band resistor color code

A 4 bands resistor color code has tolerance value color strip, the resistor on an above picture has 5% tolerance. This type of resistor uses in a regular circuit such as television,radio,washing machine.

5 bands resistor color code

A 5 bands resistor color codes have third digit color bands.
1(first digit) 0(second dig…

5 watts amplifier TDA7056A wiring diagram

TDA 7056 A is an audio power amplifier IC that has 5 watts output power with 8 ohms speaker and 3 watts with 16 ohms speaker.

The IC is simple to wiring and needs only 6 external components to make the amplifier working. TDA 7056A working with a power supply between 4.5 - 18 volts so the IC can use a battery as power supply. if you use more than 9 volts, you need to attach small heat sink to the IC.

TDA7056A has a built-in DC volume control so you can control the gain of the amplifier by changing voltage value at DC volume control pin by use a potentiometer. DC volume control makes you connect the audio signal directly to the amplifier input so it makes a sound more transparent and cleaner than a normal amplifier. 

The IC has a short circuit protection, over temperature protection, No switch-on/off clicks, ESD protected on all pins, Mute mode (The IC switch mode when DC volume control pin voltage lower than 0.3 volts) 

TDA 7056A has a very wide audio bandwidth 20 Hz to 300 KHz (Hi-fi amplifier standard frequency range = 20 Hz - 100 KHz).However, you need to keep every wire as short as possible to prevent AM frequency interfere.

Electronic components:

C1 = 1000 uf/16 volts

C2 = 0.1 uf/film capacitor
C3 = ceramic capacitor 103 or 1000 pf
C4 = 2.2 uf/ 16 volts (you can replace the ic with film capacitor if you want cleaner sound)
R1 = 1000 ohms
IC = TDA7056 A 
VR 1 = 100 Kilo-ohms potentiometer

Below picture is the circuit diagram

See TDA 7056A sound test video