Elenco Electronics Snap Circuits Instruction Manual page 5

MORE About Your Snap
Circuits Parts (continued)
SCR (Q3) - An SCR is a three pin (anode, cathode
and gate) controlled silicon diode. Like a standard
diode, it permits current flow in only one direction. It
will only conduct in the forward direction when
triggered by a short pulse or steady voltage applied
to between the gate and cathode terminals. A high
current may damage this part, so the current must
be limited by other components in the circuit.
The 7-segment display (D7)
devices today. It contains 7 LEDs that have been
combined into one case to make a convenient
device for displaying numbers and some letters.
The display is a common anode version.
means that the positive leg of each LED is
connected to a common point which is the snap
marked +. Each LED has a negative leg that is
connected to one snap. To make it work you need
to connect the + snap to positive three volts. Then
to make each segment light up, connect the snaps
of each LED to ground. In the projects, a resistor is
always connected to the + snap to limit the current.
A high current may damage this part, so the
current must be limited by other components in
the circuit.
7-segment Display:
(+) - power from batteries
A - Segment A
B - Segment B
C - Segment C
D - Segment D
E - Segment E
F - Segment F
G - Segment G
DP - Decimal Point
See project 337 for example
of proper connections.
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Elenco
If you suspect you have damaged parts, you can follow this procedure to systematically
determine which ones need replacing:
1 - 20. Refer to project manuals 1 & 2 (projects 1-101, 102-305) for testing steps 1-20, then
continue below.
21. FM Module (FM):
22. Meter (M1):
deflect full scale.
SCR:
A - Anode
K - Cathode
G - Gate
is found in many
23. Recording IC (U6):
prerecorded songs.
24. Relay (S3):
from the relay.
That
25. Transformer (T1):
Pressing the switch (S2) flashes the LED. Connect the
jumper wire to the CT point. Pressing the switch (S2)
flashes the LED.
26. Diode (D3):
Reverse the direction of D3, the LED should not light now.
27. SCR (Q3):
(S1) and the motor should not spin.
should start spinning. Now open and close switch S1, the motor
should not spin.
28. 7-Segment Display (D7):
Advanced Troubleshooting
TM Electronics is not responsible for parts damaged due to incorrect wiring.
Build project #307, you should hear FM radio stations.
Build the mini-circuit shown here, the meter (M2) should
Build project 308. Make an 8 second recording, then listen to the three
Build project #353. Turn on the switch (S1) and you should hear a buzzing sound
Build the mini-circuit shown here.
Build the mini-circuit shown here, the LED should light.
Build the mini-circuit shown here. Turn on the switch
Build project #337. All segments light, displaying the number 8.
Press switch S2, the motor
(Adult supervision
-4-