Figure 22. Phase Control (Zoom On The Right); Figure 23. Td Value Table Details - STMicroelectronics STEVAL-GLA001V1 User Manual

3.3.4 Phase control mode
Triac push
button
Triac gate
command
Wait for next zero
voltage crossing
V
MAINS
I
T
This mode is selected through the MODE switch (refer to
When you push the AC switch/Load button (Tx) ON, the
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
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.
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 - Rev 3
Figure 22.
push
td td td
Figure 23.
+
-
Phase control (zoom on the right)
push
Current in the Triac
turns off at next
zero current
cros sing
Section 3.3.1 Mode
NUCLEO-F030R8
Figure 23. td value table
td value table details
Power
td value
+
Power Time button
-
Power Time button
UM2304
Operating mode
td tp
MainsPeriod/2
MainsPeriod
tp =
MainsPeriod
selection).
development board waits for the next
details). "td" values should be
-
+
td
2
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