STMicroelectronics STEVAL-IHT005V2 User Manual page 8

Getting started
that the gate control signal is applied. If the load (example motor) is running and the LED
lights up, it indicates the MCU properly controls the Triac(s).
Blue, black and white buttons control the 3x ACS108 and Z01 in ON/OFF mode with zero
voltage synchronization. The blue button S1 controls ACS1, black button S2 controls ACS2,
black button S3 controls ACS3 and white button S4 controls T3. The different colors are
used for easy recognition of the controlled device.
ACS2 and ACS3 are controlled with 2 ms gate pulses. This is sufficient for loads with RMS
current approximately in the range of 100 mA - 500 mA. Smaller loads should be controlled
with ACS1, which has continuous gate control.
T3 is controlled with 2 ms pulses and is used for comparison with ACS2 and ACS3 behavior.
LED D10 for T3 (Z01), LED (D7) for ACS1 (ACS108-8S), LED D8 for ACS2 (ACS108-8S)
and LED D9 for ACS3 (ACS108-8S) signals that the gate control signal is applied.
The red button S5 controls relay R1. Relay is controlled in the continuous DC mode. The DC
control starts in zero voltage for control coil.
Note: The coil control in zero voltage does not lead to accurate "Zero Voltage Switching" of the
power contacts.
Button control is used in a two-step control. When the button is first pushed it turns the
related device ON. A second push of the button turns the related device OFF. All devices
controlled by buttons are set in the OFF position after reset.
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Figure 3. Overview of the demonstration board operation
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