Light Switch
I never would have thought these would be that hard to find. I am looking for a replacement switch for an overhead light in my travel trailer. On the side is stamped: DF-IS001 212481 3A 14V"T I've...
Forum Discussion
wa8yxm wrote:
So you know a switch rated for 120 or more volts AC (Standard house type switch) will have no problems with 12 volt DC. In fact it's kind of over kill. Cheaper but still over kill.
Switching DC is harder than switching AC, since AC has a zero voltage (and hence zero current) crossing 120 times every second. Any arcing that starts as the switch opens will generally dissipate during these times. With DC, on the other hand, the contacts need to move far enough apart to break the arc. If you look at the ratings for switches that have both AC and DC ratings, you'll see that the DC ratings are commonly lower than the AC ratings.
That being said, for non-safety-critical applications, I'd have no qualms about using an AC-only switch for DC applications if the voltage and current ratings are suitable. The failure mode generally is that the contacts eventually get welded together and the switch fails to open (i.e. it's stuck on permanently), and if that merely causes inconvenience rather than likely harm, it's not a huge deal to replace the broken switch.
