Velleman KNS130 Manual Del Usuario página 19

12.20 A practical example: Darkness triggered LED
Wiring Sequence
4-14-23, 22-13-12, 24-49, 48-11-17, 18-3
13
22
14
24 23
49
Complete all wiring connections as indicated in the sequence. Switch on the main switch. If you are in a
room with bright light, then the LED will not be on. When you cover the light sensor, the LED will light
up. This means the LED is switch on by darkness instead of light!.
12.21 Demonstration of a simple function of SCR
Wiring Sequence
21-50, 51-4-10, 9-53, 52-19, 20-17, 18-3
52
19
20 21
17
Complete all wiring connections as indicated in the sequence. Switch on the main switch. Nothing happens.
And then press the push switch without releasing it. The upper part of the circuit is connected and thus
current can flow though the gate (G) and cathode (K) of the SCR as it is a complete circuit. This is like
opening the gate of the SCR. And the main current can flow through the anode(A) and the cathode(K),
which lights up the LED. Release the push switch. The LED will still continue to glow! This is because the
"gate" is already opened by the initial current from the upper circuit and therefore the main current will
continue to flow through the SCR. Therefore if you want to switch off the LED, you will have to switch off
the main switch.
12.22 A practical example of SCR
Wiring Sequence
21-50, 51-4-29, 28-19, 20-17, 18-3
V. 01 – 01/02/2024
100K Ω
12 11
4 3
18
48
9
53
10kΩ
50
18
3 4
KNS130
17
10
51
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