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Technical definitons

The oscillating solenoid

On this page you will find general explanations and definitions about oscillating solenoids.
The complete catalogue is available for download.

What is a Oscillating solenoid?

From a physical perspective, oscillating solenoids generate forced, damped oscillations within a spring-mass system.

Their oscillation frequency is specified by the pulsing electromagnetic force of the integrated solenoids (drive frequency). This is always equal to the frequency of the excitation force.

The frequency of the force pulse is determined by the pulsing current in the excitation coil:

  • in case of pulsing direct current, this is equal to the pulse frequency of the current
  • in case of alternating current, this is twice as large as the frequency of the alternating current.
  • in case of alternating current with half-wave rectification or alternating current with field overlay by permanent magnets, this is equal to the frequency of the alternating current.

Oscillating drives feature several application specifics vis-a-vis other actuating solenoids. The resonance frequency (natural frequency) is the frequency at which a system would oscillate after one-time excitation due to the participating masses and springs alone.
If damping is disregarded, the natural frequency is a single degree of freedom:

F0= (1/2Π) √(c/m) (c...spring constant, m...flywheel mass)

If the units

f0 Natural frequency Hz
c Spring constant N/mm
m weight of free side kg

are used, the following adapted size equation results:

F0= 5 √(c /m) [Hz]

If the drive frequency is too close to the resonance frequency, then an extremely large cycle stroke can result, which will damage the oscillating solenoids.
Further explanations for coordination of the drive with the application are provided in the following sections.

Welche Begriffe spielen in diesem Zusammenhang eine Rolle?

Oscillation frequency fThe frequency that the device oscillates at, which is normally
50 Hz = 3000 1/min.

Maximum air gap amax


The air gap indicated on the magnet in the static state


Cycle stroke s


In case of oscillating solenoids, this is the difference between the reversing points of the armature movement in the drive direction.

Useful stroke, side, weight, mass

These relate to the part capable of oscillating that creates a useful effect.

Free stroke, side, weight, mass

These relate to the part capable of oscillating that does not create a useful effect. Ideal case: “Free of oscillations”.

Desired load weight

In case of vibratory feeder drivers as a channel weight, which make installation of a listed device possible.

Nominal power PS, S

The apparent power in case of nominal voltage.