5.8.2.1
Control of the speed of the motor
Speed control is obtained by using an electronic control system to vary the voltage (V) applied to the
motor.
The technique used consists of a "phase division" performed by the Triac. A Triac is a bi-directional
electronic switch. Closure of the circuit between A1 and A2 (anodes) takes place in the presence of the
appropriate signals received by the gate (G).
Start-up signals
Voltage to motor
5.8.2.2
Direction of motor rotation
The direction of rotation of the motor depends on the way in which the rotor and stator are connected
together. This connection is performed by two of the timer contacts or by the relays on the PCB.
EC
Electronic control
system
P
Motor overload
cut-out
S
Stator
R
Rotor
T
Tachometric
generator
TY
Triac
R1,2 Reversal relay
2005.11 dmm
Clockwise rotation
42/60
Counter-clockwise rotation
599 37 38-46