New answers tagged polarity
0
While the bare relay linked in the comments is the device the tutorial is using, the board you have already purchased should work just fine if wired correctly:
Edit: Note that I only connected the ground of the sensor to the second GND terminal of the relay board to keep the diagram tidy. The positive and negative inputs to the sensor can be connected ...
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According to the linked ad my comment was incorrect.
Input control signal voltage:
0V - 0.5V Low stage (relay is OFF),
0.5V - 2.5V (unknown state).
2.5V - 24V High state (relay is ON). <-- It takes a 12 V control signal.
Input control signal high state current:
2.5V: 0.1mA
5V: 0.35mA
12V: 1.1mA <-- It will draw 1.1 mA on the control input.
20V: 1....
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The general situation in North America (I also was not aware of the NYC ConEdison situation mentioned by Andrey Akhmetov in another answer) is that homes are provided with as much as \$200\:\text{A}\$ service (my situation, for example) with what is called "split-phase 240".
The key thing to remember is "split-phase," as that describes the situation well. ...
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simulate this circuit – Schematic created using CircuitLab
Figure 1. Supply connection, a load on L1 - N, L2 - N and L1 - L2. The transformers represent the local utility supply transformer which is generally outside the property.
Is there such a thing as phase or polarity between these three wires?
L1 and L2 will be 180° relative to each other.
...
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For a two-phase residential setup, they have a fixed phase relationship. You have a 120 Vrms sine relative to neutral on one hot, and a 120 Vrms sine relative to neutral on the other hot, with the two sinusoids 180 degrees out of phase with each other:
$$ V_A = 120 \sqrt{2}\,\text{V} \sin{\omega t}$$
$$ V_B = 120 \sqrt{2}\,\text{V} \sin{(\omega t + \pi)} = -...
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