Application notes

The EL2212 is suitable for the operation of inductive electrical switching loads such as

• Relay
• Valve
• Magnetic bearing coil
• Glue application head
• ..

Over-excited activation is useful in particular if a mechanical component such as the relay armature or the valve seat is to be moved by the magnetic force.

The activation of an inductive actuator with the EL2212 places particular stress on this. Therefore the following notes should be observed among others:

• the manufacturer’s data for the actuator for permissible/nominal current and voltage usually refer to continuous operation. In the over-excitation/excitation phase the actuator may be subjected to significantly increased values.
  → The user must ensure by his own tests or by enquiring to the actuator manufacturer that the actuator is suitable for the selected mode of operation. For example, the increased actuation voltage, the thermal load and the mechanically accelerated switching operation must be taken into account.
• In the holding phase a reduced holding current is usually applied to the actuator. This will then lie below the continuous current specified by the actuator manufacturer.
  → The user must ensure by his own tests or by enquiring to the actuator manufacturer that the actuator also possesses a sufficient holding force under the expected vibration or shock load. In addition, voltage/current may not fall to or below the dropout voltage/current.
• In both the switch-on and switch-off phase the actuator is operated with higher accelerations. This applies in particular to the switch-off procedure.
  → The user must ensure by his own tests or by enquiring to the actuator manufacturer that the switching element does not bounce, i.e. does not falsify the desired switching operation by mechanically bouncing. This can be achieved by varying the control parameters (phase time, current threshold).
• In the switch-off phase the switch-off current threshold according to 0x80n0:08 should be set to values < 0 only with caution. With smaller actuators this can considerably accelerate the switch-off; with larger actuators, conversely, it may be slowed down.
  → The user should check the effectiveness of the parameterization by oscilloscope.
• When using the EL2212 terminal in the cam controller, the programming library Motion Control XFC is available for effective use. Among other things, switching states of the cam controller can thus be directly supplied with precise switching times of the terminal.