#426 Boldport 3x7 RippleTester
Using some 4000 series counters (CD4017, CD4060) to exercise the digits and segments of the Boldport 3x7.
Here’s a quick demo..
After building the Boldport 3x7 I thought it would be nice to have a simple way to demonstrate that all the segments and digit controls are working correctly - without having to do it by hand or resort to plugging in a microcontroller.
So I whipped up this circuit on a breadboard using a CD4017 and CD4060:
- the CD4060 is configured with an RC oscillator resulting in a first counter stage (Q4) frequency of about 6 Hz
- seven CD4060 counter stages (Q4-Q10) feed the 3x7 segment pins a-g
- the next CD4060 counter stage (Q12) is hooked to reset, and also provides the clock pulse to the CD4017
- the CD4017 steps through output 0,1,2 and then resets it’s count
- the CD4017 outputs 0,1,2 feed the 3x7 digit pins A, B, C
The result is a simple pattern that runs through all combinations of segments on each digit in turn.
Note: because the CD4060 does not expose Q11 counter stage, the pattern of segments actually runs twice on each digit before moving to the next.