STMicroelectronics STEVAL-GLA001V1, Руководство пользователя

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3.3.4 Phase control mode
Figure 22. Phase control (zoom on the right)
td td
td
td tp
MainsPeriod/2
MainsPeriod
tp =
MainsPeriod
2
td
Triac push
button
Triac gate
command
V
MAINS
I
T
Current in the Triac
turns off at next
zero current
crossing
Wait for next zero
voltage crossing
push push
This mode is selected through the MODE switch (refer to Section 3.3.1 Mode selection ).
When you push the AC switch/Load button (Tx) ON, the NUCLEO-F030R8 development board waits for the next
ZVS, lights ON the corresponding LED (LEDx) and then activates the corresponding AC switch gate (Gx).
The AC switch/load is stopped when the user pushes the AC switch/Load button (Tx) ON again: the gate is
deactivated and the LED is switched OFF.
The gate command is a pulsed signal with the time delay equal to “td” value. You can modify this time delay by
pushing on the “Power Time +” button (to decrease “td” and so increase load power) or “Power Time -” button (to
increase “td” and so decrease load power).
“td” represents the time delay before turning on the AC switch at each cycle. The “td” value is selected from a
table consisting of a configurable column number (see
Figure 23. td value table details ). “td” values should be
entered in ascending order (lowest index for lowest “td” value and highest index for highest “td” value).
For safety reasons, on first load control with new values, the NUCLEO-F030R8 firmware will start with the highest
“td” value (highest index), which corresponds to the minimum power.“td” is decreased (according to the table
values) when “Power Time +” is pressed and increased when “Power Time -” is pressed.
Figure 23. td value table details
Power
-
+
td value
- +
Power Time
-
button
Power Time
+
button
Additionally, a soft-start and a soft-stop function are implemented in this mode to allow starting and stopping the
load gradually. The number of steps is configurable.
UM2304
Operating mode
UM2304 - Rev 3
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