Elenco 130-in-1 Electronics Playground - Manual (Page 100)

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You’ve built many circuits using the operational
amplifier, but there are lots of other ways to use this
handy IC. One of them is the single flash
multivibrator. With this multivibrator, you can make
the LED stay on for a preset amount of time when
the key is pressed - a single flash light.
Slide the switch to position B and construct the
circuit. Turn the power on by sliding the switch to
position A. The LED lights, but quickly turns off. Now,
press the key and observe what happens. The LED
lights and stays on for 2 to 3 seconds and then turns
off.
By using different values for C You can change the
amount of time the LED is on. Change the value of
C from 10
μF to 100μF and see what occurs to the
LED. It stays on longer.
Notes:
EXPERIMENT #81: SINGLE FLASH LIGHT
Schematic
Wiring Sequence:
31-63-94-131-138
33-67-114
85-68-110
69-82-89-93
70-134
81-86-130-124-119
90-115
109-137-129
113-116
121-135
122-132