The Application and Characteristics of Four Terminal Resistors

In the field of electronic engineering, resistors are a common component used to limit current, divide voltage, match impedance, and so on. As a special type of resistor, the four terminal resistor has become an essential tool for electronic engineers due to its unique design and wide application. This article will provide a detailed introduction to the application, characteristics, and how to choose a suitable four terminal resistor

1、 The application of four terminal resistors

A four terminal resistor has four pins, namely the nominal resistance pin, forward voltage pin, reverse voltage pin, and ground pin. Due to the fact that all four pins can be used as pins, a four terminal resistor can replace a regular single ended or double ended resistor in many situations. The following are some common application scenarios for four terminal resistors:

1. Circuit protection: A four terminal resistor can serve as an overload protection component in a circuit. When the current in the circuit exceeds the set value, the resistor will automatically disconnect to protect other components from damage caused by excessive current

2. Signal isolation: Four terminal resistors can isolate analog signals from other circuits to prevent mutual interference. For example, using a four terminal resistor at the input of an audio amplifier can effectively isolate high-frequency noise generated by power lines

3. Partial voltage regulation: Four terminal resistors can be used for voltage partial voltage regulation. By changing the resistance value, precise adjustment of the output voltage can be achieved

4. Power factor compensation: In some high power factor devices, such as motor drivers, transformers, etc., four terminal resistors can be used for power factor compensation to improve the efficiency and performance of the equipment

5. Damping oscillation: Four terminal resistors can be used in damping oscillators, and by changing the resistance value, the oscillation frequency can be adjusted

2、 Characteristics of Four Terminal Resistors

The characteristics of a four terminal resistor mainly include rated resistance, accuracy, temperature coefficient, power capacity, and working environment. Here is a brief introduction to these features:

1. Rated resistance value: The nominal resistance value of a four terminal resistor refers to the resistance value when the voltage at both ends of the resistor is 1V at 20 ° C. In practical use, due to the influence of temperature, the resistance value of the four terminal resistor may change, so it is necessary to choose the appropriate rated resistance value according to the actual situation

2. Accuracy: The accuracy of a four terminal resistor is usually expressed as a percentage, such as 1%, 5%, etc. The higher the accuracy, the smaller the measurement error of the resistor

3. Temperature coefficient: The temperature coefficient refers to the proportion of change in resistance value for every 1 ° C increase in temperature. The smaller the temperature coefficient, the better the stability of the resistor

4. Power capacity: The power capacity of a four terminal resistor refers to the maximum power that the resistor can withstand under specified operating conditions. Choosing the appropriate power capacity can ensure the normal operation of the resistor and avoid overheating damage

5. Working environment: The working environment of a four terminal resistor includes temperature range, humidity range, voltage resistance level, etc. When using a four terminal resistor, it is necessary to ensure that it can operate normally in the specified working environment

3、 How to choose the appropriate four terminal resistor

When selecting a four terminal resistor, the following factors need to be considered:

1. Rated resistance value: Select the appropriate rated resistance value according to actual needs. If the specific value cannot be determined, a slightly larger resistance value can be chosen to ensure safety

2. Accuracy: Select the appropriate accuracy level according to the measurement accuracy requirements. Generally speaking, products with higher accuracy are priced higher

3. Temperature coefficient: Select an appropriate temperature coefficient based on the actual working environment. Products with lower temperature coefficients have better stability and reliability

4. Power capacity: Select the appropriate power capacity based on the circuit load. Products with larger power capacity can withstand larger currents and power

5. Other characteristics: In addition to the above factors, other characteristics of the four terminal resistance need to be considered, such as working environment, contact area, insulation performance, etc. These factors can affect the lifespan and performance of resistors

As a multifunctional electronic component, four terminal resistors have a wide range of applications in the field of electronic engineering. Understanding its characteristics and selecting the right product can help engineers better complete various circuit design and debugging tasks