That circuit still has the buffer output connected to 5V
he's using that HC14 to sharpen up the detector output.
@ *dhenry* a Schmidt trigger input inverting buffer is good engineering practice to 'clean up' the output of a photo-transistor.The connection from the buffer output to Vcc isn't though.
Quote from: Grumpy_Mike on Dec 15, 2012, 07:46 pmThat circuit still has the buffer output connected to 5VI know... but I figured that it's just a mistake in the drawing. Hopefully it's not ACTUALLY wired that way.