Izak Theron wrote: > I'm not electronically minded so pardon the ignorant question. I'd like to > know if a servo consumes battery power only when moving or does it also > consume power to "hold" position at a certain angle?
There is idle current the servo consumes when it is not moving. This is very low. Servos can't really "hold" any position; the motor is either off or on (unlike a stepper motor). The servo constantly hunts for the desired position. Deadband keeps the servo from hunting too much and buzzing (digital servos have a very small deadband and pretty much always buzz). Technical: the servo output shaft is connected to a variable resistor (potentiometer, or "pot") which is connected to the electronics. The electronics use this resistance "feedback" to tell if the servo is at the right position. If the servo is out of position, the motor turns on full speed in the correct direction to bring the servo into position. The servo can be out of position by either a transmitter control movement, or a surface deflecting under load. > The reason I'm asking is I'm scratch building a Sagitta 900 and was thinking > of the mechanics of the spoiler setup. I will be flying the plane on my > JR421EX and obviously the spoiler has to be setup on the throttle stick. Do > you setup the spoilers so that full throttle has the spoilers fully closed > and to deploy them you have to pull back on the throttle? In this > configuration my concern is that the servo may draw unneccesary power hence > my first question. It is customary to setup spoilers with "full throttle" (up) being "fast" ie. spoliers closed. It really doesn't make a difference though what you pick. Generally it doesn't take any servo motor on-time to keep the spoilers closed (no air load). -- Andrew E. Mileski Ottawa, Canada RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off.
