Specifications

Phoenix 35 ESC showing the BEC side

The FET side is the side with the regular pattern of identical chips. The BEC side has a ran-

dom collection of chips. Do NOT use a switch between the battery and ESC. Most switches will

not handle the current and will become very hot. Also, if the battery is plugged into the heli-

copter, you should consider it live for basic safety reasons anyway.

6.4.5. Tail motor ESC

(See Chapter 31, Glossary for a definition of ESC)

You will only need a tail motor ESC if the heli has a tail motor, obviously.

For the tail motor ESC, two characteristics are important:

• High throttle resolution (256 steps or more)

Many airplane ESCs have very low throttle resolution (typically 32 steps) because airplane

radios typically have a ratchet on the throttle stick which limits the throttle resolution any-

way.

If a heading hold gyro is used with an ESC with low throttle resolution, the tail will "wag" as

the gyro tries to find the correct throttle position to hold the tail still.

If a yaw rate gyro is used with an ESC with low throttle resolution then the tail will creep left

or right because you will be unable to set the tail throttle to the perfect value with the revo

mix.

The GWS ICS-50E and probably other GWS ESCs are known to have only 16 steps of

throttle resolution

• High switching rate (>50 khz) (for brushed motors)

Many micro helis use metal brushed tail motors. Theses are easily recognizable because

there are two types:

• The popular "N20" style motors all use metal brushes.

• The IPS-style motors with grey endbells use metal brushes.

These metal brushes are very fragile and are easily destroyed by the high current surges

generated by low switching rate ESCs. Therefore it is desirable to use a high switching fre-

quency ESC to extend the operating life of the expensive tail motors.

The IPS-style motors with black endbells use carbon brushes which are less fragile, but

they will still last longer with a high switching frequency ESC. IPS motors (both grey and

black endbell) are rated for about 2 amps max current.

Helicopter Parts Selection