The Learning Circuit **|** element14 presents **|** Project Videos | VCP Biography: Karen

In the previous episode, Karen did an overview of integrated circuits or ICs. This week, Karen chose an electronics kit that contains two ICs, a phase locked loop, and a ripple binary counter. A phase locked loop takes one external input and one internal input, comparing the frequencies of their signal and turns that difference into a voltage that goes back to adjust the internal signal. This process continues until both external and internal signals are equal. This process generates an output signal that slowly changes then stabilizes. In today’s kit, an electronic dice kit, that signal from the phase locked loop IC is used as the clock input signal of the second IC, the binary counter.

The binary counter IC is a 7-stage ripple counter, with each stage generating a binary digit.

Once you understand how to count in binary, you can see that each digit is created as a square wave signal. In the end, the ripple counter IC outputs a signal that randomly flashes the 7 LEDs ending in a die roll of a typically 6-sided die.

## Bill of Material:

Part | |||
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| Velleman | 1 | Buy NowBuy Now |

9V Battery | Energizer | 1 | Buy NowBuy Now |

## Top Comments

I'm sorry to have to say this, after all your hard work researching PLLs and explaining them to us, but from the circuit diagram it looks like the designer just used the VCO [voltage-controlled oscillator…

HI Karen,

What I find most useful are the voltage and current values plus the timing for the gate operations. Next would be logic tables followed by clock pulse edges.

The voltage and current provides you…

It's fun trying to think of ways to implement dice : )

Here's my attempt (as a teenager), it was published in some magazine at a time of less scrutiny. IC1 is 40106, and IC2 is 4029.

The LEDs are…