Difference Limit Comparator
limit value switches for standard signals with 10V or 20mA inputs available direct comparison of signal difference
two non inverting inputs one inverting input
three way separation
wide-range power supplies 19Vdc...255Vac
The limit comparators allow direct comparison of voltages (0...10V) or currents (0/4...20mA). If only one input is wired, the devices can be very well employed as simple limit value switches for standard signals.
If one further input is wired with an adjustable reference signal, they can also be operated as limit value switches with remote adjustment. The provision of one inverting and of two non-inverting inputs makes it possible to compare signals of equal as well as of different polarity.
The polarity of the difference to be monitored can be set by means of a dip switch ("+" and "-"). If both contacts are closed, the limit comparator has a bipolar reaction. The dip switch thus virtually allows the modes "greater than or equal to", "smaller than or equal to", or "equal to". The switch is accessible after the side panel has been opened. The delivery default setting of the switch "+" is closed.
The switch point is adjustable with a difference of the input signals from 0.1...100%, coarse setting being made in three steps with jumper "JP1", precise setting with the helical trimmer "S". The jumper "JP1" is accessible after the front panel has been opened.
The switching hysteresis can be adjusted with potenti-ometer "HY" from 2...40% of the switch point, without changing the switching threshold by such adjustment.
A LED indicates that the preset switch point has been reached. A potential-free change-over contact and a 24V optocoupler output are at disposal for control purposes.
The device have a galvanic separation wide-range power supply, that allows a connection at all usual ac and dc supply voltages (19Vdc...255Vac). They can be snap-on mounted onto support rails TS35.