Hello,
Can you confirm that the DC voltage level above which contact erosion in cheap mechanical switches becomes very significant is 30VDC?
If you search Switch > Rocker Switch, then above 30VDC rating, there is hardly anything available. And what is available above 30VDC is extremely expensive.
Just quoting from here...
https://www.popularmechanics.com/cars/news/4226979
Can you confirm that the DC voltage level above which contact erosion in cheap mechanical switches becomes very significant is 30VDC?
If you search Switch > Rocker Switch, then above 30VDC rating, there is hardly anything available. And what is available above 30VDC is extremely expensive.
Just quoting from here...
https://www.popularmechanics.com/cars/news/4226979
So what went wrong here? The automotive industry found that switching off 42 volts wasn't that easy. Huh? A mechanical switch for, say, the window motor, has two metal contacts (well, a bunch, actually). When you press a switch, the two move into contact with each other and current flows to the motor. When you let go, they snap apart, interrupting the flow of electricity. But this doesn't happen instantaneously--the surface area of the metal contacts that touch doesn't go from something like 10 square millimeters to nothing in zero time. As the contacts move apart, the current density goes up in inverse proportion to the remaining area. And at the last instant of contact, the current density is high enough to melt and then vaporize the surface of the metal as a short electrical arc bridges the widening gap. Eventually, the contacts wear to the point that they don't work anymore. In a 12-volt system, this phenomenon was controlled by careful contact design and attention to the metallurgy of the contacts themselves. Forty-two volts draws a much longer, hotter arc, and vaporizes more metal.
Contact erosion on 42-volt systems was unacceptable, unless automakers upgraded the switches with more expensive metals and stuff such as spring-loaded contacts that jumped apart faster to reduce the arcing. Would you accept a car that had to have the switches for the power windows replaced every 10,000 miles?
Read more: Whatever Happened to the 42-Volt Car? - Popular Mechanics
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