The solenoid core is energized in this period and held by integrated permanent magnets. A second release winding integrated in the coil results in an opposed force and the core drops out again. No electrical power is required for holding the relevant switch position. Bürkert offers impulse coils designed as plungertype and pivoted-armature coils. These coils, also referred to as "zero-watt coils", are used in specific applications.
- Control from battery supply
- Undesired coil heating or no heat applied to the medium
- Holding the switch position even in the event of power failure
- Switching systems with pulse control