With the advent of electric vehicles there is new demand for a DC switching component that can handle high voltage and high current.

We'll take a close look at a high voltage DC contactor, and show you how every design decision works together to make this component safer and more reliable, even in high voltage and high current conditions.

Back in the Day

When electricity was first making its way into our everyday lives, instead of modern contactors, we had components like this knife switch. This worked for low voltage, low current applications, but it wasn't great for high voltage, high current circuits.

1. The circuit is exposed
2. It has to be operated manually
3. The mechanical opening and closing can't be done fast enough to avoid arcing, which degrades the contacting metals.

1 & 2 together are a huge safety hazard. And the larger the voltage, and the more intense the current, the greater the capability to jump air gaps. There's a limit to what a human can stand next to and operate without being electrocuted.

• The circuit is no longer exposed.
• Operation is remote.
• At low voltage, arcing is minimal. Any damage caused is so minor as to not meaningfully affect the life of the component.