How do you calculate the output voltage of a potentiometer?
1 Answer
To calculate the output voltage of a potentiometer, you'll need to understand its basic working principle. A potentiometer, often referred to as a "pot," is a three-terminal variable resistor. It has two fixed terminals and a sliding terminal or wiper that moves along a resistive element. By adjusting the position of the sliding terminal, you can change the resistance between one of the fixed terminals and the wiper.
The output voltage of the potentiometer is determined by the voltage drop across the resistive element between the wiper and one of the fixed terminals. Here's how you can calculate it:
Identify the total resistance (R_total) of the potentiometer: This is the resistance value between the two fixed terminals of the potentiometer and is typically specified on the potentiometer itself or in its datasheet.
Determine the position of the wiper: The position of the wiper is often expressed as a fraction of the total length of the resistive element. If the wiper is at the top terminal (close to one of the fixed terminals), it is at the minimum position (0% position). If the wiper is at the bottom terminal (close to the other fixed terminal), it is at the maximum position (100% position). Anywhere in between, it can be expressed as a percentage or decimal value.
Calculate the resistance between the wiper and the chosen fixed terminal (R_wiper): Multiply the total resistance (R_total) by the percentage of the position (expressed as a decimal if using a percentage). This gives you the effective resistance between the wiper and the chosen fixed terminal.
Use Ohm's Law to find the output voltage (V_output): The output voltage is calculated as the product of the current flowing through the potentiometer and the effective resistance (R_wiper). Since the current is the same throughout the potentiometer, you can use Ohm's Law, which states that V = I * R, where V is the voltage, I is the current, and R is the resistance.
If you have a known input voltage (V_input) connected across the two fixed terminals of the potentiometer and you want to find the output voltage (V_output), you can rearrange Ohm's Law as follows:
V_output = V_input * (R_wiper / R_total)
Remember to use consistent units for the resistance values (e.g., ohms) and ensure that the input voltage is within the potentiometer's operational range.
The output voltage of the potentiometer is determined by the voltage drop across the resistive element between the wiper and one of the fixed terminals. Here's how you can calculate it:
Identify the total resistance (R_total) of the potentiometer: This is the resistance value between the two fixed terminals of the potentiometer and is typically specified on the potentiometer itself or in its datasheet.
Determine the position of the wiper: The position of the wiper is often expressed as a fraction of the total length of the resistive element. If the wiper is at the top terminal (close to one of the fixed terminals), it is at the minimum position (0% position). If the wiper is at the bottom terminal (close to the other fixed terminal), it is at the maximum position (100% position). Anywhere in between, it can be expressed as a percentage or decimal value.
Calculate the resistance between the wiper and the chosen fixed terminal (R_wiper): Multiply the total resistance (R_total) by the percentage of the position (expressed as a decimal if using a percentage). This gives you the effective resistance between the wiper and the chosen fixed terminal.
Use Ohm's Law to find the output voltage (V_output): The output voltage is calculated as the product of the current flowing through the potentiometer and the effective resistance (R_wiper). Since the current is the same throughout the potentiometer, you can use Ohm's Law, which states that V = I * R, where V is the voltage, I is the current, and R is the resistance.
If you have a known input voltage (V_input) connected across the two fixed terminals of the potentiometer and you want to find the output voltage (V_output), you can rearrange Ohm's Law as follows:
V_output = V_input * (R_wiper / R_total)
Remember to use consistent units for the resistance values (e.g., ohms) and ensure that the input voltage is within the potentiometer's operational range.