MICRONOR’S new MR267 Current Loop Controller (CLC) option remotely controls a motorised potentiometer and/or rotary cam switch via 4-20mA current loop, 0-2.5V input or external potentiometer.
Available from Quality in Control , the MR267 offers a simple and inexpensive solution for automating existing systems controlled by manually-operated potentiometers, rheostats or rotary cam switches.
Motorised potentiometers (‘motor pot’) and rotary cam switches are used in a variety of industrial automation and process control applications.
They are simple to use and easy to set up. No computers required or software to write. Motor pots are easy to maintain and never obsolete.
The user-specified potentiometers provide absolute positional feedback information or function as a variable resistor in an analogue control or bridge circuit.
The motor pot provides a smooth uniform ramp throughout its timing cycle. Rotary limit switches are programmed (via cams) to electrically control events (or provide status) at pre-stages.
A few common applications include ramping up the field current of a dc motor or controlling the start-up of a generator.
These products are available in a wide variety of configurations including number and type of pots (single or multiturn, 2-170W, wire wound or composite), number and type of cam switches (electromechanical or optical), cycle time (5s to 24hrs) and packaging (DIN rail mount, panel mount, open frame, light duty or NEMA 4/4X heavy duty enclosure).
When the CLC option is specified, the MR267 control board, a MR267-dedicated rotational feedback pot and 12V dc motor are added to the configuration.
The MR267’s firmware incorporates three trimpots that can alter the conventional operating mode and scale of the motor pot.
For applications where analogue control circuits operate only within a narrower region of a pot’s full scale range, POS A and POS B trimpots are used to program positional offsets corresponding to the lowest (4mA) and highest (20mA) input values. A third trimpot, SPEED, allows the timing cycle to be fine adjusted.
The MR267 CLC option operates from commonly available 24V dc. The operating temperature range is -10°C to +65°C, with a storage temperature range of -20°C to +75°C.