With the ErP-directives becoming more and more important, there will be a shift from AC-motors towards EC-motors which are much more energy efficient. We are therefore constantly developing new products and revising existing products to be able to control these EC-motors as accurately as possible.
![Potentiometers requiring a low supply voltage Potentiometers requiring a low supply voltage](/en/files/news/image/picture/1188/potentiometers-requiring-a-low-supply-voltage.webp)
We have developed different potentiometers for stepless control of EC-motors, AC fan speed controllers or damper actuators with an analogue input. They are divided into 3 groups, depending on the needed supply voltage: Low supply voltage (3-24 VDC / 24 VAC), 230 VAC or unpowered 10 Kohm potentiometers. From this last group, the MTP-X10K-NA is by far the most popular potentiometer used to control EC-motors.
Our latest developments are situated in the group of “low supply voltage” potentiometers so let’s take a closer look to this range. Often the supply voltage for these potentiometers can come directly from the EC fan or the frequency inverter.
The SDP-M010-series needs 24 VDC supply voltage. They have Modbus RTU communication, which makes it possible to remotely control and monitor these potentiometers. They are available with OFF-position (-AT), without OFF-position (-BT) or with OFF-position and a dry contact (-DC) to remotely control an external device. This potentiometer controls the fan speed from low to high but this can be inversed via the Modbus holding registers. The same goes for the minimum and maximum output values. The enclosure is designed as such that it allows flush or surface mounting. In order to comply with most motors, you can choose between different output types: 0-10 Volt / 0–20 mA / 0–100% PWM. When the output overwrite is enabled, you can – by the value you enter in the Modbus holding register – overrule the function of the rotary knob and remotely control the analogue output of the potentiometer.
The MTP-D010-series needs a supply voltage between 3–15 VDC. Also these are available with OFF-position (-AT), without OFF-position (-BT) or with OFF-position and a dry contact (-DC) to remotely control an external device. The high and low ventilation limits are adjustable via 2 trimmers. The lowest level lies between 10 – 70% of the supplied voltage and the highest level between 30 – 100%. The enclosure is designed as such that it allows flush or surface mounting.
Our latest new development is the SDP-E0US-series, also available in the –AT, -BT and –DC version. These potentiometers need a supply voltage between 5-24 VDC. Both the minimum and maximum output levels can be adjusted in the range of 0 – 100% of the supplied voltage. This makes it possible to inverse the control output (from minimum to maximum or vice versa). There is always a minimum control range of 20% between the minimum and maximum value determined by the 2 trimmers. The splash-proof enclosure allows flush or surface mounting.
As last alternative in the range of potentiometers that need a low voltage supply we have our MTP-G010-AT. This potentiometer needs 24 VAC or 24 VDC power supply and has an OFF-position. It gives a 0-10 V output signal and the high and low ventilation limits are again adjustable via 2 trimmers. The low level lies between 0 - 7 VDC and the high level between 3 - 10 VDC. The splash-proof enclosure allows flush or surface mounting.