Talk:Crowbar (circuit)

Circuit needs a description
This article includes a single unidentified circuit diagram, but the article text describes several types of crowbar circuits. Which specific type of circuit is shown in the diagram? DMahalko (talk) 15:38, 25 January 2011 (UTC)


 * The fuse in the circut will blow if the triac is triggered. I don't completely understand the trigger, but i'm guessing it occurs when the supply voltage exceeds a limit determined by the ratio R1/R2.  Power flows from left to right:  The power supply (not shown) connects to the left-hand side of the diagram, and the protected device (also not shown) is connected on the right.  Once the crowbar is tripped, the only way to reset it is to replace the fuse. 206.210.75.84 (talk) 21:53, 6 March 2013 (UTC)
 * The TL431's trigger level is 2,5 V. Henrik Haftmann (talk) 14:59, 7 December 2022 (UTC)

Extra but undocumented functionality
This circuit using a Triac rather than an SCR has an additional protection against reversed polarity. However, residual reverse voltage is higher than using Si diodes or Schottky diodes. In case of reverse voltage, the TL431 will conduct with its output protection diode. This current will eventually fire the triac. --Henrik Haftmann (talk) 14:54, 7 December 2022 (UTC)