Using two variable inputs to dramatically increase the range of possibilites

Variable inputs are inputs which enable the user to vary the input from any particular source. Typically these are most commonly used as an active speed control with 4-20mA or 0-5V inputs being perhaps the two most common. These inputs offer a simple method by which the user or PLC can directly control the input and vary it according to the application requirements. 

However, there are a number of more advanced configurations which can be setup with two variable inputs which can enable the controller to fulfill a much broader range of functions.

Torque and Speed

Perhaps the most common setup is to use one input for torque and one for speed. This can be useful in a broad range of applications where variation is required in these two factors. Whether it be industrial equipment in which torque limits can be used to ensure perfect performance or drilling applications where accurate control of both torque and speed are the key to perfect performance. 

Using Custom Programmes to Fulfill a Range of Options

Where the use of two inputs can become exceptionally versatile is in projects where certain parameters require careful monitoring or control. Examples include advanced pumps where technology such as flow meters and pressure sensors must interact. Parameters can then be programmed into the controller to vary the flow based on any change in the pressure sensor or flow meter. Programming can be layered to include other factors such as safety features, over current protections and related functions but crucially, the two variable inputs enable accurate calibration and operation of the pump without necessarily requiring further input from a PLC or computer.

Increased flexibility means increased opportunity

The significant increase in flexibility created by the combination of two variable inputs and an onboard microcontroller means that there are a huge range of potential applications for this type of technology. The technology can be used to create closed loop systems. It can also be used to add a range of intelligent external sensors or inputs to the controller. The pressure and flow sensor example mentioned above is a good example of this but there are also a huge range of other potential inputs. Remote robots could use changes in gradient to change the torque. These inputs can then be calibrated with the drive system to ensure constant speed over a range of terrains. Equally variable inputs can be used to monitor a range of external inputs. Volume in a container can be monitored against speed enabling the user to change speed but also switch off when a container is filled.

The list goes on.

Two variable inputs in practice

The use of this technology in practice is relatively simple with the right controller. The ZDBL20DC-M brushless or brushed DC controller has been used in a number of applications to directly monitor torque and speed. Drilling applications are one such example but so too are industrial applications where fine control is required over both parameters in order to deliver the required performance. 


Using two variable inputs is a simple way to dramatically increase the potential intelligence of a controller and add huge amounts of functionality. The key to this is the onboard microcontroller which is included in virtually all Zikodrive Motor Controllers as it is this that enables the inputs to be carefully married up to the application requirements. If you have a project where you think that this might well be relevant to what you’re trying to do then we’d be happy to discuss this with you and see how we can help.