Elenco Electronics EP-130, Руководство пользователя

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Have you figured out how to make an enable circuit
using an OR gate? If so, here’s a chance to check
your design against our OR enable circuit.
As in the last two projects, a multivibrator provides
input to the OR gate in this circuit. You can see the
output of the OR gate when you look at LED 1 – it
flashes on and off according to the output of the
multivibrator. Can you tell what happens once the
multivibrator’s input is applied to the OR gate by
looking at the schematic? Give it a shot before
building the project.
Before you complete this circuit, set the switch to A
rather than B as we have done for the last two
projects. After you finish the wiring, connect
terminals 13 and 14 to turn the power on. What does
LED 1 do? And what is LED 2 doing? Now set the
switch to B. What happens to LED 1 and LED 2
now?
We simplify the circuit by saying that setting the
switch to A blocks the flow of data from LED 1 to
LED 2. (This is called the inhibit status.) But when
the switch is at B, data can flow from LED 1 to LED
2. This is called the enable status.
This is the third circuit in the family of enable circuits
so we won’t show you how it works. Try to follow the
operational flow on the schematic.
Notes:
EXPERIMENT #42: TTL “OR” ENABLE CIRCUIT
Wiring Sequence:
o
13-49-42-45-131
o
14-119
o
71-50-51-31-44-114
o
86-82-80-72-59-60-62-33-36-121-133
o
34-58
o
40-113-85
o
41-116-79
o
43-115-81
o
52-56
o
53-54-132
o
55-57
o
13-14 (POWER)
Schematic