Fr Robert Ballecer, SJ in episode 248 you reference switches that you claimed were rated for bo...

[G+_Mark Jurisch]

Fr. Robert Ballecer, SJ in episode 248 you reference switches that you claimed were rated for both AC and DC, and were cheap to boot, but the switches in the link are only AC rated, which is a huge safety concern when using them in a DC application.

 

Do you know of some switches that are rated for both AC and DC that would be useful in projects? I'm seeing most of the switches on cheap sites like Aliexpress and Banggood are advertised as being DC switches, but when you look at the pictures they are AC only.

 

I'm trying to find switches that have the same appearance in both AC and DC versions (if not in the same switch), plain black square ones are all I'm after without any real luck.

[G+_Ben Reese]

I'm curious what the risk would be of running low voltage, low current DC through a high voltage, higher current AC switch.

[G+_John Saunders]

Mark Jurisch? This is what I use, cheap and available on Amazon, rated for both AC and DC. Triggered on a LOW input like the example Padre gave.

 

[G+_Mark Jurisch]

The risk is in what it takes to break the an arc as the switch contacts open. An AC waveform zeros out twice a cycle as it alternates, where as a DC wave never zeros, so if an arc develops, the distance required between the contacts to break it are much larger than those that are needed in an AC switch, which will dramatically shorten the life of a switch and can short itself out even when you've "turned it off". While I admit the likelihood of a fire in low current situations is low, it still exists from misuse.

 

This article (among many more out there, this is just the first one I found when searching today) goes into a more detailed explanation between the two types of switches. http://www.mouser.com/blog/which-switch-who-cares-if-its-ac-or-dc

[G+_Jason Marsh]

It really would depend on the loads you're switching on and off with the relays, and the size and length of the leads running to those loads, but for most low-voltage and low-current applications you will be fine with very nearly any switch or relay rated for the amperage and voltage you intend to use, whether that rating is given as ac only or ac + dc. If you look at the common automotive relays available at any auto parts store and all over the internetz, they are built pretty cheaply, but don't erupt into a fireball every time the load is shut off.

[G+_Jason Marsh]

Geek out here, find what you want, then google the part number you want and you'll find someone selling them. Note the "Definitions" as it gives a pdf full of very useful information. Their downloadable catalog is chock full of information on relay construction, ratings, etc. as well.... te.com - Relays in Relays, Contactors & Switches

[G+_Mark Jurisch]

The problem with relays is they have be switched digitally, this doesn't always work. After looking around, I ordered a bunch of these switches which are rated for AC and DC voltages (up to 14v DC) and are $0.75 each. I'm still open to other suggestions if anyone else finds other switches that are reasonably priced and rate for both AC and DC.

 

mouser.com - GRS-4011-1600 CW Industries | Mouser