DerbyTimer.com

1-Inch Digits

This is one of the 1-inch digits, more or less actual size.
(It should be actual size on a 17-inch monitor.)
Front side of a 1-inch digit

This shows the pin connections on the back of a 1-inch digit.
1-inch_digit_connections 1-inch_digit_connections3 Timer Board Display Connector

To wire the digits, run a wire from each of the digit select pins (1 to 6 on the display connector SV) to pin 14 (marked as Digit Select) on each digit. If you have a 3-lane track, used 1 to 3, if you have a 5-lane, use 1 to 5, etc.

Next, run a wire each (I use a ribbon cable) from pins A through G on the timer display connector to the pins labeled with the corresponding letter on each digit in turn, wired in a "daisy chain" fashon, as show in the photos below. Run a wire from Connector pin A to the resitor, from the other side of the resitor to digit 1 pin A, then from digit 1 pin A to digit 2 pin A, from digit 2 pin A to digit 3 pin A, and so forth.

One thing not clearly shown in the photo of the harness at the bottom is the 68-ohm resistors you need inline between the connector and the 1st digit. I prefer to use a single 14-pin (or 16-pin, depending upon availability) DIL Resistor Network IC, like the ones on the large-digit display driver board.

(Click to zoom)
1-digit hookup schematic
Click schematic to see a larger version.

This is a closeup view of one of the digits wired up
1-inch digit wired

This is what the 1-inch digit display harness looks like:

1-inch digit harness
Click image to see a larger version.

Copyright © 2004 DerbyTimer.com