LESSON 3
DESCRIBE BASIC LOGIC CIRCUITS
TASK
Identify the switches, diodes, transistorized gates, and circuit symbols found in schematics.
CONDITIONS
Given data relating to switches, diodes, transistorized gates, circuit symbols, and schematic diagrams.
STANDARDS
Demonstrate competency of the task skills and knowledge by correctly responding to 80 percent of the
multiple-choice test questions relating to switches, diodes, transistorized gates, and circuit symbols
found in schematic diagrams.
REFERENCES
None
Learning Event 1:
IDENTIFY A TWO SWITCH AS A LOGIC OR GATE
1.
There are many circuits that perform the function of an OR gate. One of the simplest is a circuit
with two parallel switches and a lamp, Figure 3-1. The circuit is an OR gate because of the switch
arrangement in the voltage supply to the lamp. If either switch A or B is closed, the lamp will light.
Either A or B will connect +6 volts to the lamp and, since the other side is grounded, current will flow,
lighting the lamp.
Figure 3-1. Two switches as an OR gate
17
Previous Page
