Triac is a device that is automatically turned off at the zero current when not drived by a gate current. No way to turn the device off when the current is flowing.
Even if the Triac technology allows high current robustness compare to MOSFET technology, if a short-circuit of the load appears when the Triac is ON, the way to protect the Triac is to add a fuse in series with the Triac and the load.
To design the fuse and to be sure that the Triac can withstand safely the high current before the cut-off event, take a fuse with a I²t parameter below the Triac specified I²t (see datasheet of your Triac).
Hope it helps,Best RegardsBenoit
HI Benoit Renard
this is ture that when the triac is on and short circuit is occur so triac will be destroy.
now i am working on mosfet. it is working very good
thank you for replay.
Additionnal thinks regarding your choice:
To protect MOSFET against load short-circuit you need a specific complex circuit, monitoring the current with a shunt (with losses) to turn off the MOSFET in its SOA.
That's why the Triac is often preferred for dimmer purpose.
Others MOSFET drawbacks compare to Triac are: high power losses, price for a same current rating device, or very poor withstanding to lightning surge (Huge MOV is required)...
My advice is to reconsider your choice.
Moreover, according to your application requirement, a fuse is often mandatory for safety purpose, then no additionnal device/circuit to protect the Triac.
Hope it helps
HI Benoit Renard
yes. triac is better for dimmer. but i can not use fuse in my board. so when short circuit will be occur the triac will be destroy.
now i use this schamatic. but with different part number.
line voltage in 220 volt rms with 311 volt peak.
load current is 3 amper.
so which parameter (rms or peak) should be to consider when read the datasheet and study soa curve ?
Retrieving data ...