Edge Detector Circuit

A project log for NES Zapper Video Synth Theremin

Using a light gun to interact with a video synthesizer and produce sound.

Russell KramerRussell Kramer 02/21/2016 at 02:100 Comments

With the Zapper modified I'm now able to get pulses out of its detector wire, but there's still a problem. The pulses are around 100 µs long which is about the time consumed drawing four entire scanlines. I need the pulse to be much shorter. You'll understand why later on.

The detector normally outputs high and pulses to ground so I built a falling edge detector which produces a pulse lasting about 1µs