Hi,
i am new to Electric RC, while going through some of the RC online websites i noticed that there are 3 type of ESC, ESC, BESC and UESC. i was wondering what is the difference, and their uses.
Thanks

ESC: electronic speed controller ( brushed ESC used with brushed motor and brushless ESC used with brushless motor)
BEC: battery eliminator circuit
Most ESC has an integrated BEC to provide power for receiver and servos. And BEC can be divided into Linear BEC and Switching BEC.
UBEC is used when there is no BEC in a ESC or avoind excess heat when high imput voltage is connnected if you use a ESC with Linear BEC,for such kind of ESC has little capability to dissipate the heat. For example, most ESC manufacturer has HV ESCs, which is charaterized by many Lipo-packs are connect and less current so less resistance and heat, the you need a UBEC additionally to provide power for your receiver and servos.

Hope which can help you a little.

You've got even more choice now, for a few manufacturers are selling ESCs with built-in switching BECs: As star&foamy has said, the "traditional" linear BECs built into ESCs usually have a limit of 3S LiPo input voltage and 3 or 4 servos load irrespective of what load the ESC itself can take; an ESC with a built-in switching BEC is not usually subject to this restriction.

UBEC is actually a trade name for a specific stand-alone BEC (Ultimate BEC http://www.koolflightsystems.com/ultimatebec.htm), but it's often used as a generic term for all stand-alone BECs.

Another term that sometimes comes up in relation to speed controllers is "Opto": An opto ESC does not have a built-in BEC, so you must use another power supply for the receiver, such as a receiver NiMh battery or a stand-alone BEC. The reason for opto is to reduce or eliminate interference from the ESC to the receiver, which is often a major problem, and it does it by electrically isolating its throttle input circuit from its power control circuit.

"BESC" probably means an ESC with a built-in BEC, and UESC (I've never seen the term) possibly means an ESC with a built-in Ultimate BEC -- i.e. a switching BEC. I suggest you would need to read the small print to be sure what you're getting in both those cases.

ashish7202,
what kind of ESC you want to setup in your model, you can pick what you want in this website www.hifei.com
This is a professional brushless ESC manufacturer with good quality ESC at competitive prices. You can get ESC with built-in Linear and Switching BEC, also they have HV series ESC with Couple OPTO, which can filter all the noise effectively fromt the receiver. UBEC and Program Card are also in stock and outstanding.