Zenamic Metal Oxide Varistors (MOV)

ATC Semitec offer a wide range of metal oxide varistors from our leading manufacturer Semitec.

Metal oxide varistors are used to control high transient voltage surges in electronics and electrical circuits to safe levels. When a voltage surge exceeds the specified voltage, the varistor supresses the voltage to protect the circuit.

What is a Varistor?

In general, a varistor (variable resistor) is an electronic component with an electrical resistance that varies with the applied voltage. Also known as a voltage-dependent resistor, it has a nonlinear, non-ohmic current–voltage characteristic that is similar to that of a diode. But, unlike a diode, it has the same characteristic for both directions of traversing current.

At low voltage it has a high electrical resistance which decreases as the voltage is raised.

The advantages if using a varistor over other transient suppressors include:

Improved peak handling capability
High speed of response
High level of reliability – operating even at high temperatures
Offers cost- effective and compact solution

Typical Applications include:

Semiconductor device protection: Diodes, transistors, thyristors, IC etc.
Home electronics protection: TVs, air conditioners, refrigerators, microwave ovens, etc.
Office automation equipment protection: PPC copiers, fax machines, PCs, etc.
Industrial equipment protection: Robots, water heaters, machining equipment, etc.
Inrush surge protection: Electromagnetic clutches/brakes, relay control devices, circuit breakers etc.
Automotive electronics circuits
Vending machines, communication/broadcasting equipment, etc.

For further technical information, see our Frequently Asked Questions section

Call us today on 01606 871680 or complete the Contact us form, to discuss your application’s thermal sensor requirements. Using our extensive technical knowledge and innovative supplier base, we will work with you to provide the optimum solution for your product.

Semitec Zenamic MOVs
Zenamic MOVs have large surge current handling capabilities.
Peak current surges of up to 6500A (8/20 s) and peak power surges of up to 565J (10/1000 s) respectively can be limited by these fast-acting devices.
View Product Details
Semitec Zenamic Varistor.pdf

How do Current Regulating Diodes (CRDs) work?
CRDs (current regulating diodes) are diodes that maintain a constant current flow despite fluctuations in the voltage, over a wide range of voltage, from less than 1V to 100V.
Creating a constant current circuit generally involves multiple components. At ATC Semitec, we supply CRDs by Semitec, which provide the same function but as a single component.
This provides a concise, cost effective solution where space is limited.
Have a question or need a sample ? Call one of our engineers today on 01606 871680
When would you use Circuit Protectors?
Circuit protectors offer circuit protection in devices in a manner that is far superior to using fuses.
This makes them ideal for applications containing:
Relay circuits
Motors
Heaters
Transformers
Solenoids
Semiconductors
Our CRD‘s from Semitec have a wide range of operating voltages that they can steady current over, and their small size makes them a neat solution in tight spaces.
What are PTC Resettable Fuses?
PTC or Polymer PTC (PPTC) fuses carry current up to a threshold temperature. At this point, the crystalline polymer structure will change to an amorphous state, leading to a massive increase in resistance, preventing charge from being carried across the device.
The device will then remain in this high resistance state until the applied voltage is removed and they have cooled down, allowing the polymer structure inside to return to its original crystalline form. Hence, they are considered re-settable.
At ATC Semitec, we have a range of different PTC resettable fuses for use over many currents and operating temperatures.
To have a look at our current range of devices, click here.
Have a question or need a sample ? Call one of our engineers today on 01606 871680
What is a Metal Oxide Varistor (MOV)?
Metal oxide varistors are used to control high transient voltage surges in electronics and electrical circuits to safe levels. When a voltage surge exceeds the specified voltage, the varistor supresses the voltage to protect the circuit.
In general, a varistor (variable resistor) is an electronic component with an electrical resistance that varies with the applied voltage. Also known as a voltage-dependent resistor, it has a nonlinear, non-ohmic current–voltage characteristic that is similar to that of a diode. But, unlike a diode, it has the same characteristic for both directions of traversing current.
At low voltage it has a high electrical resistance which decreases as the voltage is raised.
The advantages if using a varistor over other transient suppressors include;
Improved peak handling capability
High speed of response
High level of reliability – operating even at high temperatures
Offers cost- effective and compact solution.

Have a question or need a sample ? Call one of our engineers today on 01606 871680
What are the different types of Circuit Protection?
There are many different types of circuit protection devices due to the multiple different ways that current can be limited in a circuit. At ATC Semitec, we have a range of different circuit protects to suit your appliance.
From our repeat use Inrush Current Limiters from Thinking TKS, designed to protect front-end mains voltage supplies against current spikes at switch-on, to our SEFUSE Thermal Fuses from SCHOTT which offer one-shot ultimate thermal protection from 70°C to 240°C, our range can tailor to your requirements.
For more information, and to see our full range of devices, click here.
Have a question or need a sample ? Call one of our engineers today on 01606 871680
What are Circuit Protectors?
Circuit protection devices protect the circuit from excessive temperatures, currents or short circuit in an electrical conductor. They are essentially ‘weak links’ within the circuit that are designed to fail when a fault in the system is encountered. By breaking at low currents, they limit the amount of energy that is released during electrical failure, leading to safer devices.
From PTC resettable fuses, to CRDs, to MOV’s, we have an array of different devices to that can be implemented.
To see our full range of Circuit Protection Devices, click here.
Have a question or need a sample ? Call one of our engineers today on 01606 871680