P6002ZC Teccor Electronics, Inc., P6002ZC Datasheet - Page 121

• Manufacturer Part Number: P6002ZC
• Description: 275 V, four-port longitudinal two-chip protector
• Manufacturer: Teccor Electronics, Inc.

Triac Protection
© 2002 Teccor Electronics
SIDACtor
®
Data Book and Design Guide
Thyristors
Damage can occur to a thyristor if the thyristor’s repetitive peak off-state voltage is
exceeded. A thyristor’s repetitive peak off-state voltage may be exceeded due to dirty AC
power mains, inductive spikes, motor latch up, and so on.
Thyristor Reference Circuit
Figure 3.40 and Figure 3.41 show two different methods of protecting a triac. In Figure 3.40,
a SIDACtor device is connected from MT2 to the gate of the triac. When the voltage applied
to the triac exceeds the SIDACtor device’s V
gate current which turns the triac on.
Figure 3.40 TRIAC Protection
The circuit in Figure 3.41 places a SIDACtor device across MT2 and MT1 of the triac. In this
instance the SIDACtor device protects the triac by turning on and shunting the transient
before it exceeds the V
Figure 3.41 TRIAC Protection
With both methods, consider the following designs when using a SIDACtor device to protect
a thyristor:
• V
• SIDACtor device V
• SIDACtor device must be placed behind the load
DRM
of the SIDACtor device < V
Circuitry
Circuitry
Gating
Gating
To
To
SIDACtor
Triac
DRM
DRM
> 120% V
rating of the triac.
MT1
MT2
47 Ω
Triac
3 - 33
DRM
PK(power supply)
SIDACtor
of Triac
MT1
MT2
DRM
, the SIDACtor device turns on, producing a
Load
Load
Hot
Neutral
Hot
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Neutral
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Triac Protection