Download A Simple Clock Phys 3610/6610 Lab 10 Student: TA:

Phys 3610/6610 Lab 10
Student:
TA:
A Simple Clock
Task: Using only parts from your lab kit: Design, build, and debug a circuit that will count and
display seconds from 0 to 9 endlessly.
Preliminaries: If the 60 Hz square wave does not look very good on the scope, use a LM 311
voltage comparator to clean it up with the circuit given in fig.1. This is optional, but you should
be able to explain how it works even if you do not use it.
60Hz dirty in
+12V
+5V
+5V
22k
2
10k
10k
8
−
10k
3 LM311
+
1
7
60Hz clean out
4
-12V
Figure 1: Cleaning up a clock signal
Now that you have a clean 60 Hz square wave (or 60 Hz of logic pulses), you design your circuit
from a couple of divide-by-N counters, a decade scaler, a BCD seven-segment driver, and the
7-segment display. As usual: Document all your work as you design your circuit. As you build
up your circuit through its various stages, make sure that along the way each stage functions as
anticipated. Log the tests you design for each stage along with the test results. It may take a bit
of planning to make it fit onto your breadboard.
-1-