What is the symbol for a varistor?
What is the symbol for a varistor?
Varistor symbol 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.
How do you read a 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. If it reads very low resistance, the varistor is blown.
What is varistor used for?
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.
Is there polarity on a varistor?
Does a varistor have polarity? In the case of metal oxide varistor, a zinc-oxide layer is basically sandwiched between two metal electrodes. As a result, there is no polarity.
What is the symbol of Triac?
TRIAC
| The circuit symbol for a TRIAC, where “A1” is Anode 1, “A2” is Anode 2, and “G” is Gate. Anode 1 and Anode 2 are normally termed Main Terminal 1 (MT1) and Main Terminal 2 (MT2) respectively | |
|---|---|
| Type | Passive |
| Pin configuration | anode1, gate and anode2 |
How do you use varistor in a circuit?
As such varistors are used in sensitive electronic circuits to ensure that if the voltage does suddenly exceeds a predetermined value, the varistor will effectively become a short circuit to protect the circuit that it shunts from excessive voltage as they are able to withstand peak currents of hundreds of amperes.
How do I select varistor value?
Consider the maximum continuous voltage that will be applied to the varistor including any high line conditions (i.e., 110% or more of nominal voltage). Ratings are given for continuous sinusoidal AC and DC voltages. If a nonsinusoidal waveform is applied, the recurrent peak voltage should be limited to √2x VM(AC).
Can you remove a varistor?
Just leave it open. Simply remove it untill you find a replacement.
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.
Is a varistor directional?
Modern varistors are primarily based on sintered ceramic metal oxide materials which exhibit directional behavior only on a microscopic scale. Varistors are used as control or compensation elements in circuits either to provide optimal operating conditions or to protect against excessive transient voltages.
What is the symbol of not gate?
The standard NOT gate is given a symbol whose shape is of a triangle pointing to the right with a circle at its end. This circle is known as an “inversion bubble” and is used in NOT, NAND and NOR symbols at their output to represent the logical operation of the NOT function.
