Switching relays

WEHRLE Gleichstromrelais dienen zum Schalten von hohen Strömen bei geringen Steuerleitungsquerschnitten und Spannungsverlusten. Sie werden in KFZ für die vielfältigsten Anwendungen eingesetzt.

Wir beraten Sie gerne, um das richtige Relais für Ihre Anwendung zu finden.
WEHRLE direct-current-relays are used for the switching of high currents with small control-wire diameters and voltage drops. They are used for numerous applications.

We would be happy to assist you in finding the correct relay.

Technical terms for relays:

  • Pull-in voltage: Lowest value of the energizing voltage, by which the relay picks up.
  • Drop-out voltage of a relay: Energizing voltage by which the relay reverts to stationary position.
  • Nominal voltage: Voltage for which the relay is designed.
  • Electrical service life: Number of operations with which the relay may be in service electrically.
  • Continuous current: the current which a relay can carry with a given temperature.
  • Contact consumption: Material loss of the contacts as a result of evaporation due to the influence of an electrical arc.
  • Contact clearance: Clearance between the open contacts, measured at its narrowest point.
  • Contact type:

  • Contact voltage drop: Voltage drop between the relays connectors of the closed contact by a defined current power.
  • Contact power: Power through which the contacts touch.
  • Contact making material: WEHRLE offers relays in various contact making materials. Depending on the criteria, the following materials are available to WEHRLE: PdCu, AgNi, AgCuNi und AgSnO². 
    • PdCu: Suited for circuit pulsed operation. For example: Flasher Unit usage. Drawback: high contact voltage drop. 
    • AgNi/AgCuNi: Suited as a conduit for current and switch of ohmic and iductive loads for example: rear view mirror heating, motors and valves. 
    • AgSnO²: Suited for switching of capacitive and inductive loads. For example: H4 lamps, motors, glow plugs. Drawback: fluctuating contact voltage drops, through oxide.
  • Break contact: Relays contact which is closed when the relay is in a resting position and open when it is in a working position.
  • Contact-load voltage: Is the voltage between the contacts.
  • Relays contact where in a resting position the relay is open and in the working position the relay is closed.
  • Circuit of coil: Switching off results in induction voltage which may result in a disruption of the electrical system. In order to avoid or reduce this a circuit of the coil with a choice of resistor, diode or breakdown diode may be used. With this circuit, the switching time will be increased and as a result, the service life may be reduced. Therefore, it is necessary to examine the application.