Liebert iCOM Microprocessor TM-10098 Manual de usuario descargar pdf (Pagina 117)

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Controls Training and Service Manual

116

BASIC OPERATION OF THE TRIAC

To better understand the operation of the triac, we need to look at the movement

of electrons in a special type of material used in electronics. Here we have a

semiconductor material with what is called a depletion region. The depletion

region restricts the flow of electrons to a point.

Depletion Region

Semiconductor

By forcing more electrons in to the depletion region, we can cause an overflow of

these electrons resulting in electron flow that in turn produces current. When we

have current flow, the device is on.

Depletion Region

Semiconductor Showing No Movement of Electrons

If we add a third terminal to this simple device and call it the Gate, we have a basic

triac. By sending electrons to the gate, which is connected to the depletion region,

we create an overflow condition. You can see how this device can be turned on or

off by this process. Now to put this in perspective with AC voltage circuits, this ON

and OFF condition takes place every half cycle. When the AC voltage is removed

from the gate, conduction stops.

Semiconductor Showing Movement of Electrons

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Liebert iCOM Microprocessor TM-10098 Manual de usuario Pagina 117