◎ What do the “I” and “O” on the power switch mean?


① There are two symbols “I” and “O” on the power switch of some large equipment. Do you know what these two symbols mean?

 

“O” is power off, “I” is power on. You can think of “O” as the abbreviation of “off” or “output”, which means off and output, and “I” is the abbreviation of “input”, that is “Enter” means open.

Application-of-I-and-O

② So where did these two symbols come from?

In order to ensure the stable operation of electrical equipment during World War II, it is necessary to unify the switches of electrical equipment in various fields such as the army, navy, air force and logistics, and the standard of the selector switch. In particular, the identification of switches needs to ensure that soldiers and maintenance workers in various countries can recognize and use them correctly after only a few minutes of training.

 

An engineer thought that the problem could be solved by using the binary code that was commonly used internationally at that time. Because binary “1″ means on and “0″ means off. So, there will be “I” and “O” on the switch.

 

In 1973, the International Electrotechnical Commission (IEC) officially suggested that “I” and “O” should be used as the symbols of the power on-off cycle in the technical specifications compiled. In my country, it is also clear that “I” means the circuit is closed (ie, open), and “O” means the circuit is disconnected (ie, closed).

 

③ How to choose a button switch?

1. Combined material

Common plastic switches, although insulating, are flammable and prone to safety hazards. It is recommended to choose a switch with stainless steel inlaid on the surface to fundamentally prevent contacts and improve safety.

 

2. Combine scents

Choose a colorless and odorless PC plastic power switch.

3. Combined logo

Choose products with 3C、CE certification.

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4. Combine button sounds

When using the switch, choose a power switch with crisp sound and no stagnation feeling.

 

5. Combine product appearance

The selection button has a bright, flawless, black-spotted surface. The appearance should be smooth and smooth, and the color should be uniform.

 

④ How to Install the Power Switch?

1. Before installing the power switch, it is necessary to turn off the main power supply in the home to avoid the danger of contacts;

2. Before installation, check whether the accessories of the power switch are complete;

3. Distinguish the difference between the wires, which are the live wire, the neutral wire, and the ground wire. Combine the wiring method of the power switch pins terminal to correctly link the circuit;

4. After the button switch is installed, use the testing instrument to check to ensure that the switch is normal.