Brief Notes On Potentiometer

A potentiometer is a three-terminal variable resistor whose resistance may be manually adjusted to regulate the movement of electrons. A potentiometer is a variable voltage divider.

The function of a Potentiometer

A potentiometer is a type of electrical component that is not active. Potentiometers function by changing the location of a sliding motion over a uniform resistance. The full input voltage is applied over the entire length of the resistor in a potentiometer, and the output voltage equals the power loss between both the static and sliding contacts.

The two wires of the input source are attached to the end of the capacitor in a potentiometer. To change the output voltage, slide the sliding contact along with the resistance on the output side.

In contrast to a rheostat, one end is fixed while the movable terminal is linked to the circuit.

This is a simple device for comparing the electromotive force of two cells as well as calibrating ammeters, voltmeters, and wattmeters. A potentiometer’s basic operation is straightforward. Assume we have two batteries linked in simultaneously through a galvanometer. A galvanometer is used to link the negative dc terminals with the positive battery terminals. If the electric potential of both battery cells is the same, there is no cycling current in the circuit, and the galvanometer shows no deflection. The operation of a potentiometer is dependent on this phenomenon. Consider another circuit in which a battery is linked across a resistor using a button and a rheostat, as illustrated in the diagram below.

Basic DC Potentiometer

Throughout its length, the resistor has the same impedance per unit length.

As a result, the potential difference per unit length of the resistance is constant along its length. Assume that by changing the rheostat, we receive a volt voltage drop per unit distance of the resistor.

Now, connect the positive lead of a cell to spot A on the resistor, and connect the other end which is the negative end to a galvanometer. The opposite end of that of the galvanometer is in touch with the resistor through a gliding contact. When the movable end is modified, point B is discovered. In this context, in the galvanometer, there is no current that flows and hence no displacement occurs in the galvanometer.

This means the voltage occurring within the resistor between points A and point B just balances the electromotive force of the standard cell. When the distance between locations A and B is considered as L, the emf of a standard cell E can be denoted as E= Lv volt.

Thus, the potentiometer monitors the voltage across two locations (in this case, A and B) without introducing any current into the circuit. A potentiometer’s specialty is that it can detect voltage with extreme precision.

Types of Potentiometers

Potentiometers are classified into two types:

Potentiometer (rotary) Potentiometer, linear

Although the fundamental design elements of both potentiometers differ, the operating principle of both types of potentiometers is the same. Please keep in mind that these are DC potentiometer kinds; AC potentiometer types differ.

Rotary Potentiometers

Rotary-type potentiometers are mostly utilized to provide variable supply voltage to a portion of electronic and electrical circuits. A typical example of a rotary potentiometer is the volume regulator of a radio transistor, where the rotating knob regulates the supply to the amplifier. This kind of potentiometer comprises two terminal connections between which a semi-circular pattern of uniform resistance is put. The gadget additionally has a central terminal that is linked to the impedance through a sliding motion hooked to a rotary knob. The sliding interface on the semi-circular barrier may be moved by twisting the knob. The voltage is measured across a resistive end contact and a sliding contact. The potentiometer is often known as the POT in abbreviation. POT is also used in intermediate battery chargers to change a battery’s charging voltage. There are several more applications for rotary type potentiometers where precise voltage control is necessary.

Potentiometers with Linear Response

The linear potentiometer is similar to the rotary potentiometer, except instead of rotational movement, the sliding contact on the resistor is moved linearly. Two ends of a flat resistor are linked across the dc source in this case. A sliding contact may be slid on the resistor via a rail that is attached to the resistor. The terminal linked to the slide is attached to one end of the output circuit, and one of the resistor terminals is connected to the other end. This type of potentiometer is often used in music and sound mixing systems to measure the voltage across a branch of a circuit, to measure the internal resistance of a small battery, compare a battery cell with a standard cell, and compare a battery cell with a standard cell.

Conclusion

We have learned about Brief Notes On Potentiometer, potentiometer, what is a potentiometer, the principle of a potentiometer, and all other topics related to Potentiometer.

Potentiometers function by changing the location of a sliding motion over a constant resistance. The full input voltage is applied over the total duration of the resistor in a potentiometer, and the output voltage equals the voltage drop between both the fixed and movable contacts.