A detailed introduction to ceramic vacuum relays
June 21, 2023
A detailed introduction to ceramic vacuum relays
Ceramic vacuum relay is a ceramic vacuum seal. The contact point of the relay is sealed and isolated from the outside air to obtain high voltage resistance. It is used in high voltage circuits. The vacuum seal makes the relay not easy to produce arc. In an ideal state, the vacuum may reach the dielectric strength of 10000V per 0.1mm. In addition, because there is no air, the contact will not be oxidized in the vacuum, so the contact resistance of the vacuum relay is small and stable. Especially suitable for radio-frequency applications. A typical ceramic vacuum relay consists of four basic parts: a sealed arc extinguisher chamber, where the contact point is located to withstand high pressure. Armature mechanism that drives the movement of a moving contact. The part of the coil that provides power. Additional parts for easy installation and connection by the user.
Test voltage: The voltage value used to test the voltage withstand condition of the relay medium. Generally, it is expressed by the peak value of DC voltage or AC voltage (50Hz or 60Hz). The test time is one minute.
Rated operating voltage: The maximum voltage allowed to be loaded between contacts and between contacts and ground when the relay is operating. Generally expressed as the peak value of DC or AC voltage (50Hz or 60Hz). For relays for RF applications, voltage values at high frequencies are provided.
Carrying current: The maximum current through which a contact can be closed in continuous operation.
Contact resistance: The resistance of the closed contacts in a relay, measured by running the relay through 250mA direct current to measure the voltage drop between the contacts.
Contact capacitance: Contact capacitance measures the capacitance between normally open contacts or between contacts and the ground. The measurement was carried out according to method 305 in GJB360 with a frequency of 1kHz.
Insulation resistance: The minimum resistance allowed between two test points. These two points can be contacts with the coil, contacts with the housing, the general test under 500Vdc conditions.
Coil breakdown voltage: The maximum voltage at which the coil can be isolated when the relay is properly installed.Operation time: The time interval from coil power up to normally open contact closure (rated coil voltage). This includes the time the coil establishes a magnetic field, the time the moving contact moves, and the time the contact bounces.Release time: The time between coil power failure and the return of the relay to its initial state.Contact rebound time: the time interval between the first contact and the steady contact.Mechanical life: Generally in no load, no voltage test relay can reach the life.Operating voltage: At this voltage, the relay changes its initial state.
Use and installation:
1. During the transfer or assembly process of ceramic vacuum relay, conductive salt and other dirt (such as hand sweat) may be absorbed on the surface of ceramic shell, which will reduce the high voltage performance of the product and may cause surface flying arc or leakage current of the ceramic vacuum relay. Therefore, it is best to keep the ceramic surface clean during use.
2. Avoid impact of ceramic vacuum relay, which may cause leakage, parameter change and failure of ceramic vacuum relay.
3. Due to minor material venting and other reasons, after storage for a period of time, the vacuum ceramic vacuum relay may produce 1-2 tiny surge current when it disconnects contacts or applies high voltage between contacts to enclosures. In order to avoid this current damaging the coil power supply line, the enclosures should be grounded when the ceramic vacuum relay is installed.
4, ceramic vacuum relay mainly has two fixing ways, one is flange installation, the other is thread installation. Do not make the sealing and connecting parts of the ceramic vacuum relay subject to transverse force or torsional force during installation.
Scope of application:
Rf applications: High voltage vacuum relays play a vital role in applications requiring high energy and low RF loss. These include vapor deposition during semiconductor wafer processing, radio antenna modulation matching loop, T/R (transmit/receive) conversion, pulse formation network, ion input, TWT (travelling wave tube) power supply, MRI (nuclear magnetic resonance imaging) power supply, radar system, safety inspection system, etc.
DC (DC) or AC (AC) power switch applications: including internal safety, explosion-proof applications, battery power systems, power and battery backup systems, solar and other similar power systems, industrial DC power switches,Test Equipment and instruments: ESD pulse test equipment, Hi-POT (high voltage) test, cable test, motor winding test, insulation test, high energy laser, power supply test, mass spectrometer, high voltage power supply, transformer test equipment, Ballast Test Equipment.Special applications: airfield navigation light system, submarine power distribution, earth science drilling data acquisition, scientific instruments, sine pacemaker.
That's what Meicheng Ceramics brings to you. Meicheng Ceramics is an electronic ceramic enterprise integrating R&D, production and sales. It is a listed enterprise. It is located in the electronic Ceramic Industrial Park of Xinhua County, Hunan Province, covering an area of 8W square meters. Mainly engaged in: zirconia ceramics, alumina ceramics, talc porcelain and other non-oxide ceramics research and development and application.