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GWS Top Electric Flight FAQ ☆ Note: If your question is not listed in Top Questions below, please check other links on GWS Website. |
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◆ FLIGHT GLOSSARY
BEC: Battery Eliminator Circuitry. This feature enables a speed controller to operate a receiver from the same battery that the motor uses. BEC saves weight, as it eliminates the receiver battery. C: A charging rate of C is that which will in theory fully charge a cell in 1 hour. It's actually the same number as the cell capacity but expressed in mA not mAh. E.g. for a 2000 mAh cell the C rate is 2000 mA i.e. 2A. Can Motor: Another name for a FERRITE MOTOR Capacity: Usually battery or cell capacity. It is measured in Amp Hours (AH) or more commonly milliAmp Hours (mAh). 1 AH = 1000 mAh = the ability to deliver a CURRENT of 1 Amp for 1 Hour, or 10 Amps for 6 minutes (1/10th of an hour), or 30 Amps for 2 minutes etc. Note that this is not related to voltage. It a characteristic of the CELL type. To get greater VOLTAGE you add more CELLS. Charger: Device used to recharge PACKs, usually from a 12V car/leisure type battery. These come in a wide range of prices and specifications. The main things to look for are the number of cells they will charge and the maximum current they will deliver. You will find a price jump from chargers which charge up to 7 cells and those over. That's because to charge more than 7 cells from a 12V battery requires special circuitry to increase the available voltage. Cobalt Motor: This term is generally used for brushed (conventional) motors with rare earth magnets. Some of these (Astro) actually use cobalt as the brush material but there are other materials used. Regardless of the precise material these are all commonly, if inaccurately, called cobalt motors. Energy Density: Characteristic of a cell. It is basically a measurement of how much CAPACITY you get for each unit weight. Since the cells are usually a high percentage of our total weight the higher this is the better. If you could get a 2000 mAh cell that weighs only half the conventional ones you would save a lot of weigh from the plane. ESC: Electronic Speed Control. This device is the equivalent of a throttle for electric motors. It controls the power into the motor. Many ESCs are also fitted with other facilities like BEC (see above), a brake (to stop the motor windmilling and allow folding propellers to close properly) Ferrite Motor: Brushed (conventional) type of motor with low cost ferric oxide magnets. Folder: Folding propeller. When the motor is not running the prop blades fold alongside the fuselage for lower drag (and you don't break so many blades on landing). Typically used with powered gliders. hi-rate: A hi-rate speed control switches at a high frequency, usually at around 2 to 3000 times per second. IC: IC stands for "internal combustion." I use this term to refer to all the various kinds of fuel-driven engines: gas, diesel, glow, etc... (i.e. the "normal" R/C power plant). Internal Impedance This is the main characteristic of a CELL which limits the maximum current you can get out of it. So far NiCds have by far the lowest internal impedance available. lo-rate: A lo-rate speed control switches at the same frequency as the servo signal. Roughly 50 times per second.
Opto-coupling: Indicates that the electrical current for the power system is isolated, which makes motor-induced radio interference less likely. The design of opto-coupling makes it impossible to incorporate with BEC. Soft start Some electronic switches will ramp the current up over a small time (often less than a second) when you switch on. This greatly helps to reduce wear and tear on motors and particularly gearboxes. Some ESCs also claim this feature though it only really does anything if you slam the throttle wide open from zero.
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