Why Does the Blender Emits Sparks?

Just like other electronic equipment that often fails to operate due to expiration or due to maintenance errors, blenders can also experience the same thing. One type of blender damage that occurs is the emergence of sparks from the blender engine.

Blenders in fact are dominated by electronic components such as electric motors, switches etc. will have cases of damage that are not far from the electrical components, one of them is damage to the electric motor which results in the appearance of sparks when the blender is operated.

Before going any further, we should first understand the components in Blender.

Figure 1 shows a simple blender component such as stator, rotor, commutator lamellae, carbon (carbon brushes), rotor coil, stator coil, auxiliary coil and speed controller with various functions of each.

  • The stator is a coil attached to the blender body which job is to generate the main magnetic pole and is connected to an AC current source.
  • The rotor is a coil as well as the stator which is directly connected to the drive shaft.
  • The commutator lamella is an intermediate link between the rotor and the AC power source.
  • Carbon or brushes are the end of the power cable that bridges the current into the rotor winding.
  • The auxiliary coil is a coil attached to the blender body similar to the stator coil, but with a smaller shape, intended to assist the first rotation of the rotor.
  • The speed controller is a switch that determines the amount of current flowing in the stator and rotor coil circuits in order to produce the rotor speed we want.

The main principle for the blender to rotate is the occurrence of attractive and repulsive forces between the magnets formed in the stator and rotor coils. When current flows in a conductor that surrounds an iron core, the iron will become a temporary magnet (Figure 2).

Figure 2 Electromagnetic Properties

Just like the stator coil, an iron core is wrapped around the coil so that the iron core becomes a temporary magnet. Meanwhile, the rotor coil is different from the stator coil, this coil is just a coil that is circular in the scope of the stator coil (Figure 3) attached to a special frame that is connected to the rotor shaft.

Figure 3 Schematic Diagram of an AC Electric Motor

AC current (Alternating Current) will flow to each coil (stator and rotor). In the rotor coil, current flows using the help of carbon brushes which are in direct contact with the flat curved surface of the commutator, moving around the rotor coil back and forth.

The magnetic flux that moves from the north pole of the stator iron core to the south pole hits the rotor coils and triggers a rotating force on the rotor.

The rotating force will be greater, if the magnetic flux is perpendicular to the surface of the rotor coil (the rotor coil is standing in Figure 3). In order for the rotation to be smoother, the number of rotor coils is increased as shown in Figure 4.

Figure 4 Rotor Coil

The more rotor coils, the more commutator lamellar surfaces that must be available, considering the commutator is the end of the rotor coil. The way that can be taken so that current can flow from the power source to the rotor coil is by contacting the commutator with carbon brushes (Figure 3).

When the carbon brushes are attached to the commutator surface, current will flow from the outside into the coil and vice versa. This friction process is very prone to damage, of course, considering that the rotor coil will rotate at high speed.

If, the position of the carbon brushes is not perpendicular to the commutator surface, it can trigger a spark like two hard objects rubbing against each other at high speed. This is the main trigger when the blender operates, sparks appear from the engine.

Possible causes are the condition of the brush that is tired or brittle, the installation position of the carbon brushes that is not perpendicular to the commutator surface or the commutator surface that is no longer flat. If so then the user can do simple things like checking for:

  • Condition of carbon brushes: make sure the brushes are in good condition, do not feel brittle or have cracks on the surface of the brush. If this happen, the user can replace the carbon brushes with new ones.
  • Position of carbon brushes: as shown in Figure 3, the brush position must be perpendicular to the commutator surface. If it is found that there is a shift in the position of the brushes, the user can make adjustments to the position of the brushes carefully, so as not to break the brush holder.
  • Commutator surface defects: the commutator surface should be smooth like a conductor in general. If lumps or hollows are found on the surface of the commutator, the user should replace the commutator to revitalize the condition of the blender.

Thus a brief explanation regarding the blender emitting sparks. The above analysis is the result of an analysis based on the nature of electric motors in general with similar structures and components.

Take good care of the blender, so that it is not easily damaged and don’t forget to clean the blender after use.