Frequently Asked Questions
Generators have varying voltage output based on RPM, how is this managed on this device?
The voltage is continuously converted to the desired output level based on an algorithm and advanced power electronics. (patent pending)
Does this device violate the second law of thermodynamics?
No, the power density of this particular generator design and its materials is just very high compared to other permanent magnet generators that have been available in the past.
Why is this possible now and not 20 years ago?
The rapid advancement of power electronics that are required to support everything from electric cars to solar power has made the efficient conversion of voltage possible at a scale such that meaningful amounts of power can be generated in applications like this.
Does the controller have overvoltage protection?
Yes, in addition to closed loop voltage control there are two additional measures against overvoltage. The first overvoltage protection layer continuously measures the output voltage and will shut the device down if voltages are outside of limits for any longer than a few nanoseconds. The second layer of overvoltage protection is a transient voltage suppression diode that will draw enough current to open whichever fuse(input or output) is supplying the current supporting the overvoltage event.
Are there redundant means to shut the device down?
Yes, There are primary and secondary shutdown means built into the device. They are both tested at start up and if the backup means is not functioning the device will not function.
Are generators for 28 V systems available?
Yes, at half the current level 28 V systems are available. Contact Monkworkz.
How can this device cooperate with another power source on the same bus?
If the device is run as a back up it is recommended to use the lower (14.3 V) output with the primary device setup for something higher than that voltage. In this configuration the device will enter an idle standby mode where no power will be put out until the attached bus measures ~13.7 V or lower. After a bus voltage of 13.7V at the controller is observed the device will start making power and will try to bring the voltage up to the set point (14.6 or 14.3V) based on the device configuration and current limits at the time. With this arrangement the device should not be in a situation where it is producing power with another device on the same bus and there should be no chance for the devices to interfere with each other. With this said, the device has been tested for many hours sharing the load with a traditional alternator and no issues were recorded.
Does the generator have a shear coupling?
Yes, the shear coupling is a complete redesign of the traditional shear coupling in vacuum pumps. It is more compact and allows the generator to have a shorter profile relative to other vacuum pad mounted devices.
Does the device require “phantom current” like an alternator field?
No, the device is completely self-exciting in that if sufficient RPM is supplied the device can make power. No external power is needed.
How many are installed and working in the field?
Owners and builders are terrible at letting us know that they are flying but there are more than 150 devices in the field and counting. Many of those of are flying with thousands of combined hours of operation. The list of operators includes several Reno Sport Class Racers(RIP Reno), many aerobatic competitors, several earth rounders, STOL operators, and many many more everyday homebuilders.
What are the failure modes and how can they be mitigated?
Any device will perform better in an environment with lower temperatures. Proper installation of cooling ducts will ensure that the device is exposed to the lowest temperatures possible. Testing indicates that taxi out before take off and after a heat soak, after a refueling stop for instance, will expose the device to the highest temperatures. Testing has been done with outside air temperatures of 115 F after a 20 minute heat soak interval and the device was still within temperature limits for the entire test. After takeoff the device temperatures tend to be dramatically lower.
Has the MZ-30L been tested with lithium batteries?
Yes, the MZ-30L is currently running on several aircraft with EarthX and Shorai lithium batteries.