Vert Rotor Compressors and the ZDBL15 Sensorless Brushless Motor Controller

Project Aim: An Optimised ZDBL15A Brushless Motor Controller to Deliver Exceptional Compressor Performance.

This project involved using a standard ZDBL15A sensorless brushless DC motor controller and programming it in a certain way as to optimise the performance of a micro-compressor being developed by Vert Rotor. 

As with a lot of other sensorless brushless motor control applications, major attention had to be focused on the start up phase of operation but also to optimising the top speed of the compressor (and thereby improving mechanical performance of the compressor). 

How the Project Developed

The focus of the project was in replacing what had been low cost imported brushless ESCs with a longer term industrial solution such as the ZDBL15 brushless ESC.

In doing so the aim was both to increase the life of the controller, retain the performance of the compressor whilst at the same time exploring the possibilities offered by more advanced features such as the constant speed under variable load.

Key Challenges

The most important challenge in this application was optimising the startup sequence for the compressor. As many people are aware this is often the biggest challenge when using sensorless brushless DC motors and it is made even more difficult when working in applications where starting under load is also a requirement. That said, our technical team have put a lot of time into optimising and developing successful start up procedures for such applications.

This has been achieved through a combination of carefully programmed acceleration curves and optimising the initial forced commutation for each specific motor. We often have to request a sample of the exact motor that you are wanting to use in order to be able to set this up.

By implementing these various procedures we were able to improve on the performance of the previous ESC considerably and add a range of additional control  options.

From 5 Bar to 15 Bar

One of the fundamental design principles at the heart of all of our ‘off the shelf’ range has been to make the hardware as flexible as possible so that the controllers can operate in a wide range of applications. In this way we are able to make savings on production costs by manufacturing in larger volumes and we can therefore pass these savings onto our customers who need only pay a small setup/programming fee to get a customised brushless ESC or stepper motor driver.

Vert Rotor and the Zikodrive Custom Motor Control Model

In many respects, the Vert Rotor case study is therefore an example of this model at it’s simplest. Whereas the company had previously been stuck between low cost, poorly performing brushless motor controllers and much more expensive, highly complex brushless motor controllers (which cost too much to make the application viable), with the ZDBL15 brushless motor driver it was possible to quickly setup a custom programme, carefully optimised for the specific motor and application. This delivered a technically better solution than either the low cost brushless ESCs or the more advanced controllers for a price that made the application work.


This case study clearly shows the importance of optimising programmes for motors and just how much of a benefit this can bring. It also highlights the flexibility that comes from having programmable motor controllers which can be carefully optimised for your application by an expert team.