Electrical Machines - Basic Vocational Knowledge (IBE - Deutschland; 144 pages) Introduction 1. General information about electrical machines 2. Basic principles 2.1. The magnetic field 2.2. Measurable variables of the magnetic field 2.2.1. Magnetomotive force 2.2.2. Magnetic flow 2.2.3. Magnetic flow density 2.3. Force action of the magnetic field 2.4. Voltage generation through induction 3. Execution of rotating electrical machines 4. Synchronous machines 5. Asynchronous motors 6. Direct current machines 7. Single-phase alternating current motors 8. Transformer

#### 2.2.1. Magnetomotive force

Magnetic fields are caused by electric currents.

Magnetomotive force signifies the existence of a magnetic field if the current flows through a conductor loop.

Figure 15 - Stationary induction

(1) Current-carrying conductor loop
(2) Current-carrying coil
1 Current flow direction

The current “magnetomotives” the enclosed magnetic field lines. The magnetomotive force can be increased if the same current is conducted several times through the field lines (Cp. Fig. 15). This applies for a current-carrying coil with a number of turns equalling N:

Θ = I • N

Formula sign Θ
Unit: (Theta)
[Θ] = 1A