For presetting of reference variables in analogue computing and regulating circuits, set-point adjusters are used as control desk instruments in flush mounting format or motor-driven potentiometers are used for switch cabinet mounting.
For providing the set-point output, they contain mainly single or multiple ganging potentiometers with resistor output and with current or voltage output respectively, associated with a built-in signal converter. Inductive transducer systems with current output or optoelectronic systems with digital output are available as well.
All types of transducer systems can be equipped with floating reversing switches for end-point limitation. The presetting of the set-point is carried out mostly by hand with a rotary type control knob on a dial of flush mounting instruments or carried out with motor-driven potentiometers, additionally by means of set pulses with a d.c. motor or an a.c. motor (synchronous motor). Graduation of the scale, scale angle and colour of the scale are optional according to user requirements.
Motor-driven potentiometers are mostly used as set-point adjusters in regulating circuits. Frequently they are used as signal converter as well, for instance as
- current/voltage-to-resistance converter
- measured value memory or measured value delay unit
- servo system in compensating circuits for analogue indicators
Especially for servo systems, the motor-driven potentiometer of series M7-G3O-PK613 serves in transformers or indicating instruments.
In connection with an appropriate servo-amplifier, inexpensive high precision indirect-acting measuring instruments can be realized easily for indicating purposes, for instance in
- large-scale indicators for the display of braking force in motor vehicle operational monitoring systems.
