Why sliding rheostats regulate voltage

Sliding rheostats.

Reason for regulating voltage: Sliding rheostat is an important element in the circuit, which can change its resistance by moving the position of the sliding blade, so as to play the role of controlling the circuit.

The functions are as follows: 1. The current in the circuit can be changed by changing the resistance of the access circuit part, so as to change the voltage at both ends of the conductor (electrical appliance) connected in series. When connecting a sliding rheostat, it is required:

One up and one down, the focus is on the bottom", a binding post is used for each metal rod and resistance wire; The actual connection should be selected according to the requirements of the two binding posts of the resistance wire.

2. Pray for the function of the protection circuit, that is, connect the circuit, and before the switch is closed, the sliding blade P of the sliding rheostat should be adjusted to maximize the resistance of the sliding rheostat connected to the circuit part.

3. The voltage can be changed. Ohm's law, which plays a role in changing the voltage at both ends of the electrical appliance in series with it.

Every circuit will have a voltage, the voltage is the pressure generated by the current in a fixed direction, just like the faucet always discharges water, the water pipe feeds water, the voltage is evenly divided, distributed to each electrical appliance, the resistance and voltage of the electrical appliance, phase balance, the sliding resistor is also an electrical appliance, it can also be divided into a part of the voltage, voltage and resistance phase balance, therefore, adjusting the resistance of the sliding resistor is equivalent to regulating the voltage, so that you get more voltage, reduce the voltage obtained by other people's fame, and play the role of regulating the voltage.

A sliding rheostat can change the voltage of the consumables at both ends of the circuit in series, but it cannot change the supply voltage.

For example, a sliding rheostat is connected in series with a constant-value resistor across a power supply with a constant voltage. When the sliding rheostat slide moves, the resistance value of its own access circuit changes, resulting in a change in the total resistance of the circuit, which can be known by Ohm's law, the total voltage does not change, and the total resistance changes, which will inevitably lead to a change in the total current in the circuit.

Then apply Ohm's law to the fixed-value resistance: the resistance of the fixed-value resistance does not change, and the current passing through it changes, so that the voltage at both ends of the fixed-value resistance must change. In this way, the sliding rheostat achieves the effect of changing the voltage at both ends of the fixed value resistor.

The sliding rheostat is a circuit element, which can change its own resistance and play the role of controlling the circuit from Lu Shijian. In circuit analysis, a slide talk dynamic rheostat can be used as both a fixed and variable value resistor.

The dampening effect of a resistive conductor on an electric current. Do not let the current pass smoothly, the resistance is small, the current is large, the resistance is large, the current is small, the series circuit is actually a voltage divider circuit, which means that the total voltage is equal to the sum of the voltage division. In the series circuit, the current is equal everywhere, then in U=IR, i does not change, indicating that U is proportional to R, and the resistance of the sliding rheostat becomes larger.

It can be used to change its own resistance, so as to play the role of control circuit. In circuit analysis, a sliding rheostat can be used either as a fixed-value resistor or as a variable-value resistor. The composition of the sliding rheostat generally includes five parts: binding post, sliding vane, resistance wire, metal rod and porcelain cylinder.

The resistance wire of the sliding rheostat is wound around an insulating porcelain cylinder, and the resistance wire is coated with an insulating layer on the outside.

In the series circuit, the voltage at both ends of each electrical appliance is different, when the resistance adjusted by the sliding rheostat becomes larger, the voltage applied to both ends of the sliding rheostat changes from v to v, v = r

v②=ⅰr②

r is greater than r, so v is greater than .

In the case of the partial crimping method, the resistance of the sliding rheostat is increased, and the voltage is increased.

In series circuits, r total = r fixed value + r variant.

The resistance value r of the rheostat increases, i = u r total, resulting in a decrease in the current The voltage at both ends of the fixed value resistor u = IR fixed value, will become smaller, (the resistance does not change, the current decreases) Therefore, the voltage at both ends of the rheostat u changes = u-u fixed value, which will increase (the voltage of the fixed value resistor decreases, and the total voltage does not change).