how to convert 12v to 3v using resistor

12v to 3v converter using a resistor

In this article, we are going to showing you how to convert 12v to 3v using a resistor?  This is the simple method for converting 12v to 3v, all you need to know is the voltage divider.


how to convert 12v to 3v using resistor
how to convert 12v to 3v using resistor


The voltage divider networks can be used to decrease any DC voltage, voltage divider networks only have 2 resistors. The output voltage changes according to the resistor values.


Sometimes your source voltage is higher than your required voltage, so at these conditions, you need a converter circuit. Different types of converter circuits are available on the internet, but we always search for the simple circuit, for example, resistor-based 12v to 3v converter circuit.

12v to 3v resistor

12v to 3v resistor
12v to 3v resistor


We need to know a few equations before converting 12v to 3v, so understand the equation for decreasing the voltage range from 12v to 3v using a resistor.

Resistor calculator 12v to 3v


First, you need to know the voltage divider equation, it will help you to convert the voltage variations.


V_OUT=Vin  R2/(R1+R2)


VOUT = output voltage

VIN = input voltage

R1 and R2 are resistor


This equation is used to measure the output voltage of the voltage divider circuit. Sometimes we need to know the output voltage and the input voltage, but we do not know the correct resistance value of both. This time we use another equation


R2 = R1*Vout / (Vin – Vout)

R1 = Any constant resistor( I have chosen 3k)


 R2 = 3000*3 /12-3 = 9000/9 =1000(1k)

The value of resistor R1 is 3k and the R2 is 1k

12v to 3v resistor color code

The circuit has two resistors, the value of the first resistor is 3k and the other one is 1k


1k resistor colour code
Value 1 kΩ / 1000 Ω
Type 4 Band Colour Code
Colour Code Brown, Black, Red, Gold
Multiplier Red, 100
Tolerance Gold Band ±5%


3k resistor color code
Value 3 kΩ / 3000 Ω
Type 5 Band Color Code
Colour Code Orange, Black, Black, Brown, Brown
Tolerance ±1%


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