Current regulator for electro systems
Current Regulator for switchable magnetic systems
Every power controlled 1Q control system can be used for the operation of electrical systems. As usually only 2Q and 4Q control systems are commercially available and these cannot be applied universally owing to their controlling accuracy, a relatively economy-priced 1Q control system was developed. The current control card was especially developed for the switching of inductive loads, like e.g. of electrically switchable magnetic systems - according to the principle of field displacement - or purely electromagnetic systems. From the point of view of control technique the system in question is the principle of a "low setting circuit".
The current regulator is certified according to the European Conformity law and therefore carries the CE mark. The European standard is described in EN 50081-2 and EN 50082-2 for industry electronics. To reach this conformity it is necessary to use a shielded wiring from the current regulator to the magnetic systems. And additional to that, it is recommended to install a EMC-filter directly behind the mains supply and before the input of the current regulator as it is normally used by electronically driven motors (e.g. brushless motors).
Principle of field displacement (compensation).
This concerns monostable magnetic systems being magnetically neutral in case of current conduction. In order to achieve this field displacement during the current conduction a stabilized current (seen from the temperature) is required so that the heating- up of the coil is irrelevant. A well defined temperature curve considering the heating- up of the permanent magnets would be advantageous. However this is not really required, since this temperature coefficient is clearly smaller.
To prevent the attracting force from being dependent on the coil temperature in a purely electromagnetic system, a stabilized coil current is required here as well. This is all the more urgent, if safety applications are concerned, where a certain minimum holding force has to be guaranteed.
In order to meet this requirement and save power at the same time, i.e. minimize dissipated energy, a current control card was developed which operates according to the principle of pulse width modulation.