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How are resistive loads controlled by a TRIAC?
There are three basic ways of controlling the AC power feed to resistive loads such as filament lamps or electric heaters via a triac.
What is the minimum holding current on a TRIAC?
Holding current was found by setting the gate trigger current at 15mA. The minimum operating holding current was found to be 0.302mA. At 0.301 mA, partial turn‐on was observed in the absence of a gate trigger current as shown in Figure 15 and Figure 16.
When does a triac turn on in AC?
In AC operation, turn‐on in triacs is a primarily a function of the gate trigger current. The gate trigger current is needed to re‐bias the junctions within the triac every half cycle when the load current passes through zero.
When do you need quadrant specific TRIAC rating?
The quadrant specific rating of triac gate trigger currents is normally only relevant for DC operation, when the bias of trigger voltages as well as the bias for load voltage is known and constant. The control system is an AC system, with an inductive load.
What makes a TRIAC light switch not work?
We’re zeroing in on one particular issue: a lack of load resistance. Conventional (TRIAC) dimmer switches – the ones designed to work with incandescent and halogen light bulbs – require a certain amount of “holding current,” or wattage, in order to work properly.
How does a TRIAC light bulb dimmer work?
Conventional (TRIAC) dimmer switches – the ones designed to work with incandescent and halogen light bulbs – require a certain amount of “holding current,” or wattage, in order to work properly. When paired with an incandescent, the bulb draws enough voltage for the dimmer to work with and reduce.
What can DIAC be used for in TRIAC circuit?
The diac is most often used as a trigger device in phase-triggered triac variable power control applications, as in the basic lamp dimmer circuit of Figure 6.