1-of-8 first response kit

This simple kit allows you to see which of 8 separate channels responded first. When any button is pressed, the display changes to show which button was pressed and the response is locked. Further button presses will have no effect until the reset button is pressed.

The circuit is based on a CD4511 integrated circuit which is a 7 segment driver with latch. There’s no preeprogrammed microcontroller here!

The circuit is designed to run from an operating voltage of 4.5 to 6V, so ideal for battery powered applications.

Uses include quiz games, monitoring door sensors, or anywhere you need to see which of up to 8 channels was triggered first.

For basic instructions, click here