Company News
High-Voltage Relays: The Silent Switches of the High-Voltage World

2026/05/20

In applications involving high voltage and high current, there is an unassuming yet crucial electronic component—the vacuum relay. By sealing its contacts in a high-vacuum environment and using the vacuum as both the arc-quenching and insulating medium, it achieves the unique capability of switching high voltages within a compact form factor.

1. Definition of a Vacuum Relay
A vacuum relay is a relay whose contact system is sealed within a ceramic envelope evacuated to a high vacuum. Once the internal air is removed, there are no gas molecules between the contacts, making it extremely difficult to sustain an arc and significantly enhancing insulation performance.
Theoretically, the dielectric strength of a vacuum can withstand up to 10,000 volts per 0.1 millimeter of distance. Furthermore, since there is no oxygen in a vacuum, the contacts do not oxidize, ensuring that contact resistance remains stable over the long term.

01b9af352b7e9e06f689866f8467a42e_1779267746726996.png

2. The Core of Vacuum Relays
Thanks to the unique properties of the vacuum medium, vacuum relays boast several outstanding advantages:

High Voltage Resistance: They can achieve dielectric strengths of several thousand or even tens of thousands of volts in a compact volume, making them ideal for high-voltage isolation and switching.

Rapid Arc Quenching: Vacuum arcs easily diffuse from high-pressure to low-pressure regions, allowing the arc to extinguish quickly and significantly reducing contact erosion.

Long Lifespan: Free from oxidation and gas erosion, contact wear is minimal, resulting in a service life that far exceeds that of conventional relays.

Compact Size and Lightweight: Compared to gas or air relays with the same voltage rating, vacuum relays are much lighter and more portable, facilitating miniaturized system designs.

3. Applications of Vacuum Relays
Vacuum relays are widely used in scenarios requiring "low-voltage control of high-power circuits," high-frequency switching, or high-voltage isolation. Key applications include:

Medical Equipment: Such as MRI (Magnetic Resonance Imaging) systems, which demand compact size and high reliability.

Communications and Radar Systems: Including high-frequency antenna coupling devices and radar transmit/receive switching, which require fast and stable high-voltage switching.

Semiconductor Manufacturing: Used in matching box power supplies and RF power systems for precise control of high-power currents.

High-Voltage Testing and Capacitor Discharge: Enabling the safe discharge of high-voltage energy storage systems in pulsed power applications.

7FE28C4C-31F7-4E28-B995-50B7B75C54CA.png

With their high voltage resistance, rapid arc quenching, long lifespan, and compact size, vacuum relays have become indispensable core components in high-voltage, high-frequency, and space-constrained systems. Though rarely known to the general public, it is precisely these critical, silent core devices that underpin a wide range of high-tech applications, from everyday medical equipment to cutting-edge space exploration. Companies like GLVAC, which focus on independent R&D and cultivate core technologies, serve as a solid driving force for steady progress in this field.



分享

Latest News

Get Professional Solutions

We are looking forward to engaging with you to explore more solutions for electric vacuum devices.