Sensor offers greater efficiency with no need for chopper stabilisation
Brushless DC motors need to operate more efficiently as energy and cost savings become a bigger concern. With this in mind, Honeywell Sensing and Control has developed a sensor technology for use with brushless DC (BLDC) motors that removes the need for chopper stabilisation, resulting in a product that has a faster response time, greater accuracy and minimal electrical noise without the need for additional filtering and the commensurate costs.
BLDC motors are growing in popularity due to their higher energy efficiency using electronic commutation versus mechanical commutation to control power distribution to the motor. Traditionally, though, most BLDC motor designers turn to chopper stabilisation to mitigate any sensitivity and stabilisation issues without thinking about the new advances that are available. Designers want the best – and this technology is claimed to be a more efficient and cost-effective solution without any 'traditional' manufacturing drawbacks.
At the heart of the technology is a quad Hall element and proprietary programming resulting in a highly sensitive and stable sensor tailored to meet the needs of designers using BLDC motors.
It means that OEMs get all the high sensitivity and stability requirements across a range of temperatures that are required in different sectors such as robotics, portable medical equipment and HVAC technologies and appliances where quieter and more efficient motor performance is of critical importance.
Initially designers may be cautious of using a sensor that does not have chopper stabilisation, but not only does the technology overcome chopper stabilisation drawbacks, it also brings additional performance advantages of faster response time, repeatability, improved jitter performance and no additional electric noise generation over a range of temperatures.
To prove the point, Honeywell tested the new non-choppper-stablised sensors against a number of chopper-stabilised products – including those with claimed higher sensitivity.
The test involved mounting and centring samples as close to each other as possible so that they all experienced the same environment on a circular target with 48 magnetic pole pairs used to trigger the product samples. All results were measured against a Top Dead Centre (TDC) trigger that had a very fast response time.
The results were impressive. In all cases the new technology delivered significantly better performance results in every area ranging from higher sensitivity and repeatability to faster response times.
Comparison testing results for reliability and response time showed that the non-chopper stabilised parts had a repeatable output with a response time that was between 10 µs to 20 µs faster than chopper-stabilised products, including the high-sensitivity samples.
Testing also showed that even if the repeatability issues could be overcome, the chopper-stablised sensors still showed a slower response time, resulting in lower efficiency.
