Principle and precautions of sliding line variable resistor

　　Sliding line rheostatThis product is suitable for circuits with AC 50HZ, below 380V, and DC below 440V. It can be used in the electrical and mechanical design phase to change current, voltage, and as a substitute for variable resistors with undetermined resistance values. Sliding line variable resistor is a current and voltage regulator used for research experiments or teaching demonstrations in the laboratory, as well as used as an excitation and speed control resistor for power generation equipment and DC motors.

1、 Working principle of sliding line rheostat

Sliding line variable resistor is one of the commonly used devices in electricity. Its working principle is to change the resistance of the circuit by changing the length of the resistance line connected to it, gradually changing the magnitude of the current in the circuit. The resistance wire of a sliding resistor is usually a nickel chromium alloy with a high melting point and high resistance, while the metal rod is usually a metal with low resistance. Therefore, when the cross-sectional area of the resistance is constant, the longer the resistance wire, the higher the resistance, the shorter the resistance wire, and the lower the resistance

The main technical indicators of a sliding line variable resistor are full resistance and rated current (power). Special attention should be paid to ensure that the current passing through any part of the variable resistor does not exceed its rated current. Commonly used in laboratoriesSliding line rheostatTo change the current or voltage in the circuit, connect them separately into a current control circuit and a voltage divider circuit. When using, it should be noted that before connecting the power supply, the sliding terminal T in the current control circuit should be placed at the position with the highest resistance (N terminal); In the voltage divider circuit, the sliding terminal T should be placed at the position where the resistance is the smallest (N terminal).

2、 Precautions for sliding line rheostat

The main technical indicators of a sliding line variable resistor are full resistance and rated current (power). The selection should be based on the size and adjustment requirements of the external load, especially noting that the current passing through any part of the variable resistor is not allowed to exceed its rated current. Commonly used in laboratoriesSliding line rheostatTo change the current or voltage in the circuit, connect them separately into a current control circuit and a voltage divider circuit. When using, it should be noted that before connecting the power supply, the sliding terminal T in the current control circuit should be placed at the position with the highest resistance (N terminal); In the voltage divider circuit, the sliding terminal T should be placed at the position where the resistance is the smallest (N terminal).