Vacuum relay


  Definition and Structure

Definition: A vacuum relay is an electrical device that uses a vacuum tube to achieve current switch control. It is mainly composed of vacuum tubes, control circuits, contacts and springs.

Structure: The vacuum tube is the core part of the vacuum relay and consists of a vacuum gap between two electrodes. The contact is responsible for opening and closing the circuit, and the spring plays the role of restoring the initial state of the contact.

  Working principle

The working principle of the vacuum relay is that the gap between the cathode and the grid forms a segmented charge barrier through the excitation contact in the control circuit. When a sufficient reverse bias occurs across the gap, a corona discharge is induced between the cathode and anode, turning the vacuum tube on. This process is similar to the principle that the electric shock mechanism of an ordinary relay converts the energy stored in the coil into a magnetic field.

Vacuum relay is a relay with contact in vacuum and vacuum as the medium, usually with glass or ceramic as the shell, and the contact is made of non-magnetic high conductivity metal.

  Characteristics of vacuum relay

Vacuum relays have high electrical strength; rated carrying current and conversion current are large, contact electrical wear is small, and life is long; contact resistance is small and stable, and ohmic noise is low; relatively speaking, vacuum relays are small in size, distributed capacitance and inductance between electrodes Small, small contact opening distance, low excitation power, fast breaking speed; sealed contacts are not affected by surrounding air pressure, water, sand and dust or explosive gas, can work in harsh environments.

Vacuum medium is a very ideal insulation medium, its high breakdown voltage, is 110 ~ 40kV/mm, equivalent to more than 10 times the air medium. The arc formed between the contacts in vacuum can spread around at a very fast speed, so it has a very fast medium recovery rate, which can reach 25kV/μS, which can extinguish the arc in a very short time, and the arc extinguishing time is only half a cycle at power frequency.

Therefore, the vacuum relay has high breakdown voltage, fast arc extinguishing and large breaking current. The vacuum interrupter also provides a clean and stable environment for the contact, making the contact resistance low and stable. It is suitable for flammable and explosive environments without polluting the environment. Due to the high insulation strength of the vacuum, The contact opening distance is small, the action is fast, the excitation power is small, its service life is long, and it is suitable for frequent conversion.

  Use

Vacuum relays are widely used in radio communication equipment, radar, power supply, broadcasting and other electronic equipment, such as antenna coupling, RF coil tap change, antenna transceiver conversion, pulse forming network conversion, high-voltage high-power circuit snap switch, automatic grounding (leakage). In addition, it can also be used in corrosive or explosive environments.

Typical vacuum relays are named as follows:

       JPK-2/009

     J: relay p: high frequency k: vacuum 2: model number 009: specification number (the last three digits of the product drawing number)

Directory

 

Serial Number Product Model Serial Number Product Model Serial Number Product Model
1 JPK-3/002 type vacuum relay 8 JPK-2/009/054 type vacuum relay 15 JPK-31/065B type vacuum relay
2 JPK-4/003 type vacuum relay 9 JPK-6/055/055A type vacuum relay 16 JPK-31/067 type vacuum relay
3 JPK-5/004 type vacuum relay 10 JPK-23/059, JPK-2/061 type vacuum relay 17 JPK-31/067A vacuum relay
4 PK-7/005 type vacuum relay 11 K-2/057/062 type vacuum relay 18 JPK-33/069(k) type vacuum relay
5 JPK-11/008 type vacuum relay 12 JPK-2/063, JPK-23/063A type vacuum relay 19 JPK-35/073A type vacuum relay
6 JPK-10 type vacuum relay 13 JPK-31/065 type vacuum relay 20 JPK-35/073(H) type vacuum relay
7 JPK-13/013 type vacuum relay 14 JPK-31/065A type vacuum relay 21 JPK-36/074 type vacuum relay