What Is A Mov In Electronics

November 15, 2024 Post a Comment

What is a mov in electronics

A Metal Oxide Varistor (MOV) is a protection component used in power supply circuits that is powered directly from AC mains. It is used to protect the circuit from high voltage spikes by varying its resistance.

Is a MOV a varistor?

MOV refers to the metal oxide varistors. MOV has a symmetrical volt-ampere characteristic curve (as shown in Figure 1). When MOV is applied, it is generally connected in parallel in the circuits.

What is MOV in engineering?

Motor Operated Valve (MOV)

What is the purpose of varistor?

Varistors are used to protect a circuit from high voltage surges. When a high voltage surge is applied to a circuit, the outcome is usually catastrophic to the circuit. A capacitor may be installed across the signal lines. However, this capacitor cannot suppress voltage surges.

What is MOV and how it works?

The most common modern type of varistor is the metal-oxide varistor (MOV). This type contains a ceramic mass of zinc oxide grains, in a matrix of other metal oxides, such as small amounts of bismuth, cobalt, manganese oxides, sandwiched between two metal plates, which constitute the electrodes of the device.

What happens when a varistor fails?

Under different current conditions, failure modes include electrical puncture (see Figure 4), physical cracking (see Figure 5), and thermal runaway. Cracking happens because varistors are basically a ceramic material, and hitting them with a sharp high-amplitude surge is like hitting a dinner plate with a hammer.

What are the advantages of MOV?

MOV is a convenient file format because it can hold different media elements, including video and audio, all in one compact place. It stores data so you can easily edit the file if you need to, without the hassle of rewriting.

Does MOV have polarity?

Are MOVs sensitive to polarity? A. No. Since MOVs provide bidirectional clamping, they are not a polarized device.

How does a MOV fail?

The prominent failure mode for the MOV is sustained overvoltage. Under these conditions, the MOV begins to conduct power frequency (50 Hz to 60 Hz) current. The MOV ultimately reaches its maximum energy capacity and enters thermal runaway.

What is MOV in instrumentation?

An MOV is a combination of two separate devices, usually provided by two separate manufacturers. – Valve Assembly. a mechanical device to optimize a desired fluid control function, such as isolation or throttling. – Actuator.

What does MOV stand for in Assembly?

(1) An assembly language instruction that copies data from one location to another. See move and machine instruction. (2) (MOVie) A QuickTime video file extension.

What is MOV in motors?

Motor operated valves (commonly abbreviated as MOV on P&IDs) are valves that are actuated by electric motors. Motor operated valves are generally large valves used in different kinds of operations. Due to the large size of the valve actuator, an electric motor is needed to open or close a valve.

How does a MOV varistor work?

Metal Oxide Varistor's are semiconductor devices who's resistance changes from a very high open circuit condition to a very low short circuit condition to clamp any surge or voltage transient in an electrical circuit.

How do you check if a varistor is working?

How do you test for varistor? Touch one meter probe to the free varistor lead and the other probe to the connected lead. Read the resistance on the meter. If it reads nearly infinite resistance, the varistor is still good.

Is varistor a resistor?

A varistor is a voltage dependent resistor (VDR). The resistance of a varistor is variable and depends on the voltage applied. The word is composed of parts of the words “variable resistor”. Their resistance decreases when the voltage increases.

How MOV is connected in circuit?

It is connected to any direction because there is no polarity for electrodes like a resistor. To increase the energy handling capability, the MOV is in parallel to the circuit, which is to be protected. While producing the higher voltage ratings to the circuit, it is connected in series.

Can you remove a varistor?

Just leave it open. Simply remove it untill you find a replacement. The circuit will work without it.

How do you identify a varistor?

The varistor circuit symbol can be seen to be very similar to that of a thermistor. It consists of the basic resistor symbol of a rectangle with a diagonal line through it that has a small added section parallel to the body of the resistor symbol. This indicates the no-linear nature of the varistor.

What happens when a MOV blows?

This high voltage will decrease the resistance value of the MOV to a very low value making it appear like a short. This forces a large current to flow through the MOV which would blow the fuse and disconnect the circuit from the mains voltage.

Why does a varistor burn out?

The surge energy is too large and exceeds the absorbed power; 8, the pressure is not enough; 9, current and surge are too large and so on. The safety of the use of varistors has always been a problem that needs attention.