Alternator

ALTERNATOR POWER SYSTEM: The alternator system consists of a belt-driven alternator, a voltage regulator/ alternator control unit mounted on the left hand side of the firewall and circuit breaker located on the instrument panel. The system is controlled by the left hand portion of

the split rocker, master switch labeled "ALT." Thru 1978 models an over-voltage sensor switch and red warning light labeled "HIGH VOLTAGE" are incorporated to protect the system. Beginning with 1979 models, over-voltage and under-voltage switches are contained within the alternator control unit and a red warning light labeled "LOW VOLTAGE" is installed on the instrument panel). The aircraft battery supplies the source of power for excitation of the alternator.

   
ALTERNATOR: The alternator is three phase. delta connected with integal silicon diode rectifiers. The alternator is rated at 28 volts at 60 amperes continuous output. The resulting do output is applied to the aircraft bus and sensed by the voltage regulator. The regualtor controls the excitation applied to the alternator field thus controlling the output of the alternator

     
ALTERNATOR FIELD PROTECTION: A 5-amp automatic resetting circuit breaker located on the left hand. instrument panel stiffner. is provided to protect the alternator field circuit.
ALTERNATOR REVERSE VOLTAGE DAMAGE. The alternator is very susceptible to
reverse polarity current because of the silicon diodes. The diodes. having a very high resistance to reverse current flow, are used without any cutout relay such as used on a generator system. The alternator diodes are arranged with their cathodes connected to the aircraft bus bar which is positive and no back current will flow. If the polarity of the battery is reversed, the diodes will offer no resistance to the current flow. The current rating of the diodes is exceeded and diode failure may result.
OVER-VOLTAGE WARNING SYSTEM The over-voltage system consists of an over-voltage sensor switch and red warning light labeled "HIGH VOLTAGE". The over-voltage sensor is attached to the wire bundle behind the instrument panel and the light is located on the right hand side of the instrument panel. When an over-voltage trip off occurs the over-voltage sensor turns off the alternator system and the red warning light comes on. The ammeter will show a discharge. 
VOLTAGE REGULATOR ;The voltage regulator is a solid state regulator. The regulator is a remove and replace item and not repairable in the field. 
ALTERNATOR CONTROL UNIT ;The alternator control unit is a solid state voltage regulator with an overvoltage sensor and low-voltage sensor incorporated in the unit. The control unit is not adjustable and is a remove-and-replace item.

 

Cessna 152 Fuselage

Cessna 152 Fuselage

 
2. WINDSHIELD AND WINDOWS: The windshield and windows are single-piece; acrylic panels set in sealing strips and held by formed retaining strips, secured to the fuselage with screws and rivets. Sealant used in conjunction with a felt seal is applied to all edges of windshield and windows with exception of the wing root area. The wing root fairing has a heavy felt strip which completes the windshield sealing
3. WINGS: Each all-metal wing is a semi cantilever, semimonocoque type, with two main spars and suitable ribs for the attachment of the skin. Skin panels are riveted to ribs. Spars and stringers complete the structure. An all-metal, piano-hinged aileron, flaps and a detachable wing tip are mounted on each wing assembly. A single metal fuel tank is mounted between the wing spars at the inboard end of each wing. Colored navigation lights are mounted at each wing tip
5. HORIZONTAL STABITIZER: The horizontal stabilizer is primarily of all-metal construction. Consisting of ribs and spars covered with skin. Stabilizer tips are of ABS construction. A formed metal leading edge is riveted to the assembly to complete the structure. The elevator trim tab actuator is contained within the horizontal stabilizer. The underside of the stabilizer contains a covered opening which provides access to the actuator. Hinges are located on the rear spar assembly to support the elevators.
6. WING STRUTS: Each wing has a single lift strut which transmits a part of the wing load to the lower portion of the fuselage. The strut consists of a streamlined tube with fittings for attachment at the fuselage and wing.
7. FIN: The fin is primarily of metal construction, consisting of ribs and spars covered with skin. Fin tips are of ABS or glass fiber construction. Hinge brackets at the fin rear spar attach the rudder.