[sdiy] First DIY synth (555 osc.'s)

[Neil Johnson]

> "crowbar effect" ??
>
> Elby

As in, "putting a crowbar across the rails" - i.e. a direct short.

Sometimes used to protect expensive circuits from overvoltage faults.
Place a fuse in the supply line and an SCR directly across the supply
rails after the fuse.  If the supply voltage goes above a certain safe
threshold then trigger the SCR, which will stay turned on for as long as
there is power applied.  This shorts out the rails, which will (hopefully)
blow the fuse before the PSU goes bang.  Either way the expensive circuit
is protected from damage.

Neil
--
Neil Johnson :: Computer Laboratory :: University of Cambridge ::
  http://www.cl.cam.ac.uk/~nej22           +44 (0) 1223 334 477