Elenco 130-in-1 Electronics Playground - Manual (Page 48)

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If you don’t know what an exclusive OR means, don’t
worry. An exclusive OR (abbreviated XOR) circuit
provides a high output only when one or the other of
its inputs are high.
You can see that an XOR circuit produces a low
output, only if both of the inputs are the same (high
or low). If the inputs are different (either high and low
or low and high) it results in the output being high.
This circuit is handy to let us know if we have two
inputs that are the same or if the inputs are different.
Before completing this circuit, be sure you have the
switch set to B. Once you have finished connecting
the wiring, connect terminals 13 and 14 to turn the
power on. Now watch LED 1. Press the key to
produce a high input. Is there any change in the LED
1? To make both inputs low release the switch. To
make the input through the switch high, set the
switch to A. What does LED 1 do?
Press the key while leaving the switch at A to make
both the inputs high. Now you can see that in an
XOR circuit, you need two high inputs to produce a
low output.
If desired, you can build an XNOR circuit (exclusive
NOR). We will not build one here, however, you might
be able to figure how to do it. Hint: It is almost
identical to the NOR circuit followed by additional
wiring in order to reverse the circuit. Make sure that
you keep track of your experiments in your notebook,
particularly if you make an XNOR circuit.
Notes:
EXPERIMENT #33: “EXCLUSIVE OR” DTL CIRCUIT
Wiring Sequence:
o 13-45-132-137
o 14-119
o 44-31-75
o 76-84-82-33-121
o 81-40-138
o 41-130
o 48-42-128
o 43-47
o 46-80
o 79-129-125
o 83-126-127-131
Schematic
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Want to create an amplifier that mixes two tones
together? There are many different types of tone
mixing circuits, but the operational amplifier is
considered one of the best.
After you complete the wiring, slide the switch to
position A to turn on the power. Note the timbre (the
tone) of the sound produced. To mix this tone with
another, press the key. You can alter the two separate
tones by changing the values for the two 10k
Ω
resistors.
The tone mixer amplifier allows you to mix two tones
together by modifying resistances with no need to
change the other circuits.
Notes:
EXPERIMENT #94: TONE MIXER
Wiring Sequence:
o 1-29
o 2-30
o 3-49-91-119-124
o 5-67-90
o 50-51-85-106
o 52-53-54-87-86
o 55-88-105-113
o 56-57-75-110
o 58-59-60-76-77
o 78-61-109-111
o 62-70-134
o 63-131
o 68-82-84-89
o 69-92
o 81-112
o 83-138
o 114-137
o 121-135
o 122-132
Schematic