Latching relays


Latching relays

A latching relay is a two-position electrically-actuated switch. It maintains either contact position indefinitely without power applied to the coil.  It is controlled by two momentary-acting switches or sensors, one that 'sets' the relay, and the other 'resets' the relay. The latching relay maintains its position after the actuating switch has been released, so it performs a basic memory function.

There are two kinds of latching relays:

One latching type has two opposing coils with an over-center spring or permanent magnet hold the contacts in position after the coil is de-energized. A pulse to one coil turns the relay on and a pulse to the opposite coil turns the relay off.

Another latching type has a remanent core that retains the contacts in the operating position by the remanent magnetism in the core. This type requires a current pulse of opposite polarity to release the contacts. A variation uses a permanent magnet that produces part of the force required to close the contact; the coil supplies sufficient force to move the contact open or closed by aiding or opposing the field of the permanent magnet.

Time Chart

 Time diagram   A pulse to one coil turns the relay on and a pulse to the opposite coil turns the relay off. 
Filter
Latching relays

310 relay - Latching, safety critical, 18 contacts

  • Latching relay using 2 separate coils and magnetic rocker mechanism
  • Plug-in design with secure locking feature for maximum ease of maintenance
  • 18 double break contacts in all N/O and N/C combinations
  • Weld no transfer safety contacts standard
  • Optional gold contacts
  • Optional gold and silver contacts
  • Contact life (mechanical) of 100 million cycles
  • -40 °C...+80 °C operating temperature
Latching relays

407 relay - Latching, safety critical, 40 contacts

  • Latching relay using 2 separate coils and magnetic rocker mechanism
  • Plug-in design with secure locking feature for maximum ease of maintenance
  • 40 double break contacts in all N/O and N/C combinations
  • Weld-no-transfer safety contacts standard
  • Positive mechanical keying of relay to socket is done during manufacturing
Latching relays

BD-U200 relay - Latching, plug-in 4 pole

  • Latching (bistable) relay
  • Compact plug-in design
  • 2 combined coils
  • 3 C/O contacts and 1 N/C contact
  • Magnetic arc blow-out
  • Flat, square silver plated relay pins for excellent socket connection
  • Wide range of sockets
  • Integrated snap lock
  • Transparent cover
  • High DC breaking capacity
  • Optional positive mechanical keying relay to socket
  • Flexibility by many options
Latching relays

KCD-U200 relay - Latching , 2 pole

  • Latching (bistable) relay
  • Compact plug-in design
  • 2 C/O contacts
  • 2 galvanic isolated coils
  • Clear position indicator (optional)
  • Weld no transfer contacts
  • Flat, square and silver plated relay pins for excellent socket connection
  • Wide range sockets
  • Integrated snap lock
  • Transparent cover
  • Optional positive mechanical keying relay to socket
  • Flexibility by many options
Latching relays

KCS-U200 relay - Latching , 2 pole

  • Latching (bistable) relay
  • Compact design
  • 2 C/O contacts
  • 2 galvanic isolated coils
  • Weld-no-transfer contacts
  • Flash barrier
  • 2.8 x 0.8 faston connections
  • Transparent cover
Latching relays

KDN-U200 relay - Latching, 8 pole

  • Latching (bistable) relay
  • Compact plug-in design
  • 8 C/O contacts
  • 2 galvanic isolated coils
  • Clear position indicator
  • Magnetic arc blow-out
  • Flat, square and silver plated relay pins for excellent socket connection
  • Wide range sockets
  • 2 integrated snap locks
  • Transparent cover
  • High DC breaking capacity
  • Optional positive mechanical keying relay to socket
  • Flexibility by many options
Latching relays

SB relay - Latching, 4/3 contacts

  • Latching relay using 2 separate coils and magnetic rocker mechanism
  • Two types available with 4 C/O (type 400) or 3 C/O (type 300) contacts
  • All contacts are double make - double break contacts (form Z), 8 A
  • Plug-in design with secure locking
  • feature for maximum ease of maintenance
  • Optional Weld no transfer contacts
  • Contact life (mechanical) of 100 million cycles
  • -40°C...+80 °C operating temperature
Latching relays

SBG relay - Latching, 4/3 gold contacts

  • Latching relay using 2 separate coils and magnetic rocker mechanism
  • Two types available with 4 C/O (type 400) or 3 C/O (type 300) contacts, gold plated on silver
  • All contacts are double make - double break contacts (form Z), 8 A
  • Plug-in design with secure locking feature for maximum ease of maintenance
  • Optional Weld no transfer contacts
  • Contact life (mechanical) of 100 million cycles
  • -40°C...+80 °C operating temperature
Latching relays

SC relay - Latching, 8 contacts

  • Latching relay using 2 separate coils and magnetic rocker mechanism
  • Double break in all N/O and N/C combinations
  • Plug-in design with secure locking feature for maximum ease of maintenance
  • Weld no transfer safety contacts standard
  • Contact life (mechanical) of 50 million cycles
  • -40°C...+80 °C operating temperature
Latching relays

TFBBU 400 relay - Flip flop, 4 contacts

  • Delay flip flop relay
  • Transient pull-in mode or drop-out mode programmable by dip switch
  • Status LED indicator
  • Plug-in design with secure locking feature for maximum ease of maintenance
  • 4 double make / double break C/O contacts (form Z), 12 A
  • Weld no transfer contacts standard
  • Contact life (mechanical) of 100 million cycles
  • -40 °C...+85 °C operating temperature