The life application of the rheostat, the role of the rheostat

A rheostat is a device that adjusts the size of the resistor, and the amount of current can be adjusted when connected to the circuit. In general, a rheostat consists of a wire with a high resistance and a device that can change the contact point to adjust the effective length of the resistance line.

It is used to adjust the volume of the knob on the Walkman, the knob to adjust the light on the desk lamp, the knob to adjust the light and dim on the computer, and the knob to adjust the temperature of the electric iron.

All adjustable appliances are necessary.

Electric furnace heat, fan speed, range hood wind power, lamp brightness, electric car speed, audio volume, etc.

For example, the modulation of the electric fan, the sound of the audio, and the brightness of the lamp.

Adjustable brightness lamps.

Electric cooker with adjustable heat.

Radio volume.

The speed of the fan.

Electric car speed.

Speaker volume.

Adjustable brightness lamps.

Electric cooker with adjustable heat.

Radio volume.

The speed of the fan.

Brightness adjustment of the lamp.

Fan.

The functions of the rheostat are:

1. Limit the current and protect the circuit.

The most common rheostat is a sliding rheostat, which works by changing the resistance of the conductor by changing the effective length of the conductor in the access circuit, thereby controlling the current or voltage in the circuit. The resistance wire of the sliding rheostat is generally a nickel-chromium alloy with a high melting point and large resistance, and the resistance rod is generally a metal with low resistance, so the longer the resistance wire, the greater the resistance.

2. Change the distribution of voltage in the circuit.

The shorter the resistance rod, the lower the resistance. The resistance wire is coated with an insulating layer on the outside, wound around the insulating tube, and its two ends are connected to two binding posts A and B. The sliding vane p is connected with the binding post C by the metal rod, and when the sliding vane moves to different positions, the length of the resistance wire between the two binding posts A and C is not the same, so that the size of the resistance in the access circuit can be changed.

Rheostat principle

The principle of a rheostat is to control the current or voltage in the circuit by changing the resistance of the conductor by changing the effective length of the conductor in the access circuit. a knob on the Walkman to adjust the volume level; a knob on a desk lamp to dim the light; A knob on a computer to adjust the brightness or dimming of the display; The knob that regulates the temperature of the iron, these are the applications of the rheostat.

A general rheostat consists of a wire with a high resistance and a device that can change the contact point to adjust the effective length of the resistance wire. The regulating role of the sliding rheostat in the circuit is reflected in the current limiting and voltage dividing methods.

The structure of the sliding rheostat: porcelain cylinder (insulating tube), coil (resistance wire), sliding vane, metal rod, binding post, etc.

Note: If you select 4, you can select the first 4.

Additional Knowledge: The Varistor Principle of Sliding Rheostat: The resistance is changed by changing the length of the resistance line in the access circuit, thereby changing the current in the circuit.

The function of the sliding rheostat is: (a) to change the current and voltage in the circuit by changing the resistance in the circuit; (b) Protect the circuit.

Nameplate of sliding rheostat: A sliding rheostat is marked with the word "50", and 50 indicates that the maximum resistance of the sliding rheostat is 50 or the rheostat range is 0 50. Indicates that the maximum current allowed through the sliding rheostat is.

How to use the sliding rheostat: simply put: select, series, connect, and tune.

a) Select the appropriate sliding rheostat according to the nameplate (i.e. the maximum rated current cannot be exceeded when used);

b) should be used in series in circuits;

c) The wiring should be "one up and one down" (not at the same time with the two above binding posts (equivalent to the wire) and at the same time with the two lower binding posts (equivalent to a fixed value resistance);

d) Before closing the switch, the resistance value should be adjusted to the maximum place (i.e., the position where the current is minimized) (purpose: to protect the circuit).

Applications of sliding rheostats: potentiometers.

I hope it helps you, and if you have any questions, you can ask them

I wish you progress in your studies and go to the next level! (*

We are glad to answer for you, and the answer to your question is: 1. The connection principle of the sliding rheostat is "one up and one down" (one end is connected to the metal rod, and the other end is connected to the binding post on the resistance wire). (If the above two binding posts are connected, it is equivalent to connecting a guide to the first defense line; If two binding posts on a resistor line are connected, a fixed-value resistor is connected.

None of the sliding coarse rheostats can change the resistance and thus the current or voltage). 2. The principle of changing the resistance value of the sliding rheostat: "far big and near small" - the farther the distance between the slider P and the lower binding post, the greater the resistance value, and the closer the resistance value, the smaller the resistance value.

1) Before using the sliding rheostat, it is necessary to figure out its maximum resistance value and the maximum current value allowed to pass through the stove When using, it shall not exceed the maximum current value allowed to pass through 2) Before using the sliding rheostat, the slider should be slid back and forth several times to remove dust and other dirt on the contact point to ensure good contact Before connecting to the circuit, the sliding piece p should generally be moved to the place where the resistance value is the largest to protect the power supply and the electricity meter (3) Correctly connected to the circuit Be careful not to connect to a fixed resistance (connect both ends of the circuit to a, b) Or connect it into a short circuit (connect both ends of the circuit to C and D respectively) (4) During the experiment, be careful not to damage the insulation layer of the resistance wire, so as not to cause an inter-turn short circuit