【Instrument Beginners】Why must instruments use a 24V power supply? ?
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Why must instruments use a 24V power supply? ? I would like to ask the experts here!
It’s not necessary to use a 24V power supply; 24 volts is safe and universally applicable
There are 220-volt ones and 5-volt ones
Personally, I think 24V power supplies are safe, readily available, and have become a standard.
:o Is 36V or less safe for the human body? Why must it be 24V and not 28V, 30V, or 16V?:lol
For the human body, a safe voltage is already 12 volts; it used to be 36 volts, but that has been changed
Instruments generally have a wide operating voltage range; currently, they can function at a minimum voltage of 9–10 volts. Considering the voltage drops due to transmission losses, a voltage of 24 volts is sufficient to meet the operational requirements of most instruments. This is one of the reasons why 24 volts is used. Since instrument measurements are often based on current, a voltage of 24 volts or higher ensures more stable current supply for these instruments.
Taking into account factors such as the 4-20mA signal current, transmission distance, and cable cross-sectional area, 24VDC is a reasonable choice; as various manufacturers adopted 24VDC, it became a standard. Just like with fieldbus communication protocols, at first they operated independently; eventually, the standard of the manufacturer that managed to dominate the market became the standard recognized by everyone.
To be honest, when I saw the title, I thought the original poster would be struggling with 24VDC and 220VAC. But after reading the content, I feel like you’re overcomplicating things – is it really meaningful to worry about numbers like 36, 18, 20?