On 2008-10-16, RST Engineering (jw) wrote:
OOOOkay, I'm not seeing the humor. Either reverse biasing an LED will in
fact turn it off (page 65) or somebody reinventing 4000 series logic on page
66. Which one is the knee-slapper?

Jim

There's an (inadequate) 1N914 diode to protect the LED from the 100-150v,
reverse bias but the diode is saved by the fact that the TL431 has max V(KA)
of 37V

Bye.
Jasen