Velleman projects K8028 Assembly instructions - Manual (Page 18)

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 Function 13: Speed control for synchronous motors.
Only connect synchronous motors when using this function, other loads could damage the
module or the connected unit !
Synchronous motors are mainly used for fans. The speed of these motors cannot be changed efficiently
by phase chopping, only by proportional control. It works by passing and then blocking proportionate peri-
ods of the sinusoidal mains voltage.
Operation: From the rest state (LD4 lights up): Press the pushbutton briefly to start the motor. In the first 2 sec-
onds, the motor is driven 100% to ensure a normal run up (LD3 flashes during these 2 secs.), after which the
motor will run at state 1. By pressing the button briefly you get the following states on each press:
- State 1: 40%* of the max. speed (LD3 lights up).
- State 2: 60%* of the max. speed (LD2 lights up).
- State 3: 75%* of the max. speed (LD1 lights up).
- State 4: 100%, motor runs at max. speed (LD1 flashes).
- State 5: OFF, motor stops (LD4 lights up).
*These figures are only indicative and depend on the motor used
If the motor stops (LD1 lights up), the function of the K8028 can be changed with SW1. This is not possi-
ble if the motor is running.
Control: One or more parallel switched pushbuttons.
Application: Speed control of a fan.
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page 18 Monday, August 27, 2012 10:04