PowerZone is a custom-built electronic control designed to convert the motor drive signal on ready-to-fly model aircraft with proprietary electronics to a signal that can be interpreted by a standard electronic speed control, thereby allowing the use of a brushless motor without the need to replace the entire electronic system of such aircraft.
The onboard control, roughly the size of a North American dime, was designed and built by electronics and radio control enthusiast Thomas Black of Folsom, California, USA. A lead from the control is soldered to the negative lead running from the original speed control to the original drive motor. The positive lead is not used and the original speed control now serves as a signal source. The incoming signal is converted to a standard three-lead radio control device control signal which, as pointed out earlier, may be interpreted by any discrete electronic speed control. An LED is used to verify that a signal is being received and converted.
Discussion of the PowerZone began in October 2005 at rcgroups.com while the product was in development. Favorable response led to final development and distribution; even the name originated at rcgroups.
PowerZone is intended for use with most HobbyZone and ParkZone models (hence the name) as well as micro helicopters with a single main rotor, such as the E-flite Blade CP and similar helicopters. It is currently available via mail order through HeliDirect.com of Malden, Massachusetts, USA under the "HDX" brand name.
Some care should be exercised in the use of early PowerZone boards in helicopters with motor-driven tail rotors because of a minor firmware problem which creates a sharp spike in the throttle curve, resulting in excessive current draw, interference to the gyroscope and the possible sudden loss of control while transitioning to high throttle settings. The problem was eliminated starting with revision 1.2 which actually learns the specific throttle curve of the controller and adjusts its signal accordingly. This new version has largely replaced the original version in the sales pipeline. Older versions may be reprogrammed free of charge via the manufacturer; contact information may be found via the link at rcgroups.com shown below.
As of May 2007, firmware version 1.3 is the most recent, written to address an occasional problem with erratic motor operation and subsequent loss of control. The new revision has overcome the problem.