I have a schematic which uses a triac, for example a BT136. Please have a look at the attached schematic (this is a schematic for a soldering station)

soldering station

What parameters from the datasheet we should take into consideration, when we are searching for a equivalent triac?

For example, if I used BT138 instead of BT136, will the soldering station work correctly?

I searched the datasheets for both BT136 and BT138, and I saw that the gate trigger current for BT138 is higher that the gate trigger current of BT136. Meanwhile, in the MOC3041 datasheet it does not mention the maximum current, only the surge current. So I can't find if the BT138 is compatible with MOC3041.

I am wondering if I can use BT138 as a substitute for BT136, in the uploaded schematic?


Later Edit: I searched again for datasheet using the exact part number of the two components and it seems that the gate current is the same for both components. Please confirm if I am right. I apologize.

  • \$\begingroup\$ Add in the datasheet links so we're all discussing the same parts. \$\endgroup\$ – Transistor Aug 31 '18 at 15:20
  • \$\begingroup\$ I added the links in the first message. @Transistor \$\endgroup\$ – mike_mike Aug 31 '18 at 15:24
  • \$\begingroup\$ Latching current looks a bit higher for the 138, but that's about it. Looks like a suitable substitute to me. \$\endgroup\$ – calcium3000 Aug 31 '18 at 18:18
  • \$\begingroup\$ @calcium3000 I do not find in datasheet what is the max current for MOC3041 triac at pins 4 and 6. Could you please tell me what is the max current for MOC3041 internal triac ? \$\endgroup\$ – mike_mike Aug 31 '18 at 20:33

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