Electronic Products Assembly And Servicing (EPAS) PDF

ELECTRONIC PRODUCTS ASSEMBLY AND SERVICING EPAS MAINTAIN AND REPAIR CONSUMER ELECTRONICS MOTOR CONTROLLED APPLIANCES MARIE CONCEPCION S. TVL-11 TURA LESSON OBJECTIVES: To identify the external and internal parts of an electric fan and explain it...

ELECTRONIC PRODUCTS ASSEMBLY AND SERVICING EPAS MAINTAIN AND REPAIR CONSUMER ELECTRONICS MOTOR CONTROLLED APPLIANCES MARIE CONCEPCION S. TVL-11 TURA LESSON OBJECTIVES: To identify the external and internal parts of an electric fan and explain its functions. Measure the resistance of motor winding using an Ohmmeter. WHAT IS AN ELECTRIC FAN? It is a type of electronic appliances that is run by an electronic motor.  WHAT’S THE PURPOSE OF AN ELECTRIC FAN? To convert electrical energy to mechanical energy. To make consumers feel comfortable during hot seasons or summer days. EXTERNAL PARTS OF AN ELECTRIC FAN  EXTERNAL PARTS OF AN ELECTRIC FAN 1. Base. Supports the entire mechanism. Usually where you will find the on-off switch (regulator), which may have 2 or 3 optional speeds - low, medium, and high. 2. Motor Housing. Contains the electric motor - the rotor to which the blade assembly is attached.  EXTERNAL PARTS OF AN ELECTRIC FAN 3. Blade/Impeller assembly. Cuts the air and pushes it forward. 4. Blade guard. Prevents curious fingers or kitty cats from suffering injury. 5. Power cord with plug. Connects to your home’s electric service power supply.  INTERNAL PARTS OF AN ELECTRIC FAN 1. Electric Motor - It is the main part of the electric fan that produces mechanical energy to make the propeller rotate. 2. The Stator - It is a non movable part of the electric motor that provides electro magnetic energy to the rotor.  INTERNAL PARTS OF AN ELECTRIC FAN 3. Rotor – It is the movable part of the electrical motor that rotates. 4. Copper Winding / Coil - It is a set of copper wire that supplies electricity in the stator and rotor.  INTERNAL PARTS OF AN ELECTRIC FAN 5. Capacitor - The capacitor is used not only to start the fan but also to make it spin. In simple words, the capacitor creates a magnetic flux (torque) which makes the fan rotate. 6. Thermal Fuse - a thermal fuse or thermal cutoff is a safety device which open circuits against over heat. It detects the heat caused by the over-current due to short circuit or component breakdown. INTERNAL PARTS OF AN ELECTRIC FAN 7. Selector Switch /Control Switch - It is a part of electric fan that can intensify the produce air for the consumers. Push button switch Rotary switch MOTOR RESISTANCE ∙ The Higher Resistance means a Low Current which will result slow rotation of the propeller. The Lower Resistance means a Higher Current which will result in fast rotation of the propeller  FAN SPEED CONTROL ∙ Since that the no.1 in the selector switch has a slow rotation of rotor it means that the resistance needed is high. ∙ No.2 in the selector switch will have a moderate resistance and the no.3 has a lowest resistance SCHEMATIC DIAGRAM MOTOR TERMINALS /TEST POINTS There are six (6) colored wires in an electric fan motor. These wires are connected to the winding or coil inside the stator. These are called the Test points where you can do resistance measurements of the winding/coil (Below is the pictorial and schematic diagram)  DIAGRAM Pictorial Schematic Wire terminals There are six (6) Test points  HOW TO MEASURE RESISTANCE OF MOTOR WINDING/COIL Instructions: ∙ Using a digital multimeter / tester, measure the resistance of the winding by placing the test probes between the two the Test points. ∙ Connect the multimeter test probes between two test points and examine the resistance reading. Fig. 1.1 Testing the coil resistance by (As shown in Fig. 1.1) the test points. Testpoint Testpoint Resistance Reading 1 2 468 Ohms  ACTIVITY 1 Given an electric fan motor Measure the resistance between each Test Point. Complete the table by writing the resistance measured between each Test points. Record each resistance reading. Testpoint Testpoint Resistance Reading 1 2 2 3 3 4 4 5 5 6