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…

lm3914 schematic diagram and test

If you want to make a simple VU meter. LM3914 is the best choice for you. It's easy to make VU meter or 10 dot/bar DC level meter with lm3914. 

lm 3914 can withstand +-35 volts input without any damage so you can make VU meter even you are new in electronic DIY.

The circuit uses minimal component to make the job done.
List of component:
R1 = 1 kilo-ohms
R2,R3 = 4.7 kilo-ohms
R4 = 10 kilo-ohms
ic = lm 3914n-1 (lm3914)
C1 = 4.7 uf at least to 47 uf (better bass respond)
10 LEDs red,green,yellow,orange or whatever you want
9 - 12 volts DC power supply

LM3914 schematic diagram

   Lm3914 VU meter video, the video show step by step guide and circuit explanation.

Now, I add a sine wave rectifier circuit to lm3914, it makes the dot mode more accuracy.

Real dot mode VU meter schematic diagram


  1. 👌 Thanks for great idea for me. Actually I'm not expart. But I'm really interested. Actually i want to build a music vu meter. & I did it by using LM3914 IC with a basic circuit diagram. & I found actually what i want. Sorry for my bad English.

    1. You're welcome. I'm not an English expert so don't worry about it

  2. Sir i need a little help from you. 1➡I don't have 1n4048 diode. Can i replace with 1n4148???

  3. Thanks again & again.
    ➡I want to add more then 10 led using 1 lm3914. Is it possible?


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