FlyFreak

RC Modeli => Elektronika i baterije => Topic started by: miso227 on June 30, 2010, 08:04:36 pm

Title: oznaka KV
Post by: miso227 on June 30, 2010, 08:04:36 pm
Može li mi netko malo pojasniti te KV oznake motora ja to nekužim da ga jeb!!
Title: Odg: oznaka KV
Post by: laki on June 30, 2010, 08:38:18 pm
KV oznaka je kratko receno to koliko motor ima okretaja pri dovedenom jednom voltu napajanja
npr. 1000Kv motor i baterija 11,1V ispada    1000X11,1=11100 okretaja motora
Title: Odg: oznaka KV
Post by: Wespen on June 30, 2010, 08:41:01 pm
Googole je zakon
The Kv rating of a design of brushless motor is the  constant relating the motor's unloaded RPM to the peak (not RMS)  voltage on the wires connected to the coils (the "back-EMF"). For  example, a 5,700 Kv motor, supplied with 11.1 V, will run at a nominal 63,270 rpm. By Lenz's law (http://en.wikipedia.org/wiki/Lenz%27s_law), a running motor will create a back-EMF proportional to the RPM.
Once a motor is spinning so fast that the back-EMF is at the battery  voltage (also called DC line voltage), then the motor has reached its  "base speed". It is impossible for the ESCs to "speed up" that motor,  even with no load, beyond the base speed without resorting to "field  weakening". For some applications (e.g. automotive traction and high  speed spindle motors) it is normal to exceed the base speed with a  factor of 200 to 600%.
Kv is the voltage constant (capital-K, subscript v), not to be confused with the kilovolt (http://en.wikipedia.org/wiki/Volt), whose symbol is kV (lower-case k, capital V).

Iliti po naski - broj okretaja pri narinutom 1 V napona
Title: Odg: oznaka KV
Post by: SDespot on June 30, 2010, 09:21:11 pm
Ono što članak ne pojašnjava jest činjenica da su brushless motori sinkroni uređaji čija kutna frekvencija (brzina vrtnje) izravno ovisi o frekvenciji izmjenične struje kojom su pogonjeni i broju magnetskih polova. Stoga je KV oznaka čisto informativnog karaktera jer će stvarna brzina vrtnje motora ovisiti o osobinama kontrolera koji pretvara istosmjernu struju u izmjeničnu prema raspoloživom naponu i odzivu motora.
Title: Odg: oznaka KV
Post by: miso227 on June 30, 2010, 09:34:49 pm
dečki hvala puno!