will a regular household 110v light switch work on 12v DC ? - Fiberglass RV


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-27-2012, 12:05 AM   #1
Junior Member
 
Trailer: No Trailer Yet
Posts: 2
Question will a regular household 110v light switch work on 12v DC ?

Hi guys,
I have searched/ cross searched, youtubed, googled, everything i can think of....

I want to save on buying 20-30$ light switches in my boler, so i was hoping to use household switches, any idea how to wire those in a 12V DC setup?

when i plugged the wires in directly and then hooked up my LED's to the little tiny holes in the back the wires from the battery got REALLY HOT....

what am i doing wrong?

Please help!

thanks
__________________

__________________
Suavek K is offline   Reply With Quote
Old 05-27-2012, 12:10 AM   #2
Senior Member
 
floyd's Avatar
 
Name: Floyd
Trailer: 2004 13 ft Scamp Custom Deluxe
IllAnnoy
Posts: 6,046
Registry
Yes , a standard household light switch will work on 12V if wired correctly,but it sounds like you hooked both wires from the battery to the switch!!
That's a NO-NO!
You should break the Positive wire across the standard light switch to the load and return the Negative wire schematically directly back to the negative side of the 12V source. Also...most modern 110V dimmer switches will not work work on 12V.
Most 12V switches are about $3... What are you trying to do??
Contact me directly if you need further assistance.
__________________

__________________
floyd is offline   Reply With Quote
Old 05-27-2012, 01:06 AM   #3
Senior Member
 
Byron Kinnaman's Avatar
 
Name: Byron
Trailer: 2006 Scamp 13' towed with a 2005 Dodge Dakota 4.7l Magnum W/full tow package (over kill)
Oregon
Posts: 6,307
Registry
You can go to any Radio Shack, Wal-Mart, hardware store and find lots of switches that are smaller than household light switches.

Think loop.... The wires from the battery will form a loop when connected to the switch and the light. The switch either completes the loop or opens the loop. (light is on when loop is completed, off when open).

Be careful when messing with 12volt systems and batteries. A battery can delivery a lot of current for a short period of time. Enough to burn up any trailer wiring.

It would be best if you found somebody close that could help you with your wiring. Trailer fires aren't much fun.
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 05-27-2012, 01:32 AM   #4
Senior Member
 
Roy in TO's Avatar
 
Name: Roy
Trailer: 1972 boler American and 1979 Trillium 4500
Ontario
Posts: 4,954
Quote:
Originally Posted by floyd View Post
Most 12V switches are about $3...
To get an idea of what is available search ebay for "12V switch"
__________________
Roy in TO is offline   Reply With Quote
Old 05-27-2012, 01:19 PM   #5
Senior Member
 
Trailer:
Posts: 787
On a more general issue of using house voltage switches on 12v circuits, it isn't ideal if you are trying to conserve a battery. If you are hooked to the mains via a converter, then it doesn't matter much.

Household voltage switches are designed not to arc/spark (and so eventually burn out) when they are operated by opening the contacts wide enough - but the current is low enough that the resistance doesn't matter. 12v switches don't need much of a contact gap, but the current is big enough that a low resistance is required, to avoid a voltage drop at the switch that will, for example, reduce the output of a light connected to the circuit.

If you dismantle a household switch, you'll usually find contacts that work like a pair of hands clapping - quick to make or break, but not very good contact. In contrast most 12v switches use 'wiping' contacts (just like the exposed switches in Dr Frankenstein's lab!) where the wiping action keeps the contacts clean and so lowers resistance.

Now this is the situation here in Yurp where we use that scary 240volt electricity - maybe an American expert will tell me that 110volt switches don't work that way, though I bet they do.
__________________
Andrew Gibbens is offline   Reply With Quote
Old 05-27-2012, 03:57 PM   #6
Senior Member
 
Byron Kinnaman's Avatar
 
Name: Byron
Trailer: 2006 Scamp 13' towed with a 2005 Dodge Dakota 4.7l Magnum W/full tow package (over kill)
Oregon
Posts: 6,307
Registry
Quote:
Originally Posted by Andrew Gibbens View Post
On a more general issue of using house voltage switches on 12v circuits, it isn't ideal if you are trying to conserve a battery. If you are hooked to the mains via a converter, then it doesn't matter much.

Household voltage switches are designed not to arc/spark (and so eventually burn out) when they are operated by opening the contacts wide enough - but the current is low enough that the resistance doesn't matter. 12v switches don't need much of a contact gap, but the current is big enough that a low resistance is required, to avoid a voltage drop at the switch that will, for example, reduce the output of a light connected to the circuit.

If you dismantle a household switch, you'll usually find contacts that work like a pair of hands clapping - quick to make or break, but not very good contact. In contrast most 12v switches use 'wiping' contacts (just like the exposed switches in Dr Frankenstein's lab!) where the wiping action keeps the contacts clean and so lowers resistance.

Now this is the situation here in Yurp where we use that scary 240volt electricity - maybe an American expert will tell me that 110volt switches don't work that way, though I bet they do.
Wiping action is needed for low current circuits. 12 Volt, 120 Volt, or 240 Volt circuits can be low current or high current, they can be high inductance or simply resistive. The difference in switches is the spacing of the contacts. 12 Volt contacts can be much closer together than 120 Volt and 120 volt contacts can be closer than 240 volt and so on and so on.

When I said low current that would be current in less than 100 mA. Most trailer lights are in 1 to 2 Amp area.

A smaller switch might be a good idea only because of how it would look in a small trailer.
__________________
Byron & Anne enjoying the everyday Saturday thing.
Byron Kinnaman is offline   Reply With Quote
Old 05-27-2012, 06:37 PM   #7
Senior Member
 
Name: None
Trailer: None
None
Posts: 2,730
AC Switches

Quote:
Originally Posted by Andrew Gibbens View Post
On a more general issue of using house voltage switches on 12v circuits, it isn't ideal if you are trying to conserve a battery. If you are hooked to the mains via a converter, then it doesn't matter much.

Household voltage switches are designed not to arc/spark (and so eventually burn out) when they are operated by opening the contacts wide enough - but the current is low enough that the resistance doesn't matter. 12v switches don't need much of a contact gap, but the current is big enough that a low resistance is required, to avoid a voltage drop at the switch that will, for example, reduce the output of a light connected to the circuit.

If you dismantle a household switch, you'll usually find contacts that work like a pair of hands clapping - quick to make or break, but not very good contact. In contrast most 12v switches use 'wiping' contacts (just like the exposed switches in Dr Frankenstein's lab!) where the wiping action keeps the contacts clean and so lowers resistance.

Now this is the situation here in Yurp where we use that scary 240volt electricity - maybe an American expert will tell me that 110volt switches don't work that way, though I bet they do.
You are correct that is why the switch is labeled 120VAC only! The sine wave of AC helps extinguish the arc on making or breaking the switch
Applying DC to an AC rated switch does not work well and a waste of money. You can buy AC /DC rated switches for less than 20 bucks
__________________

__________________
steve dunham is offline   Reply With Quote
Reply

Tags
light


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
rv frig 110V to 12V sugermc Problem Solving | Owners Helping Owners 23 07-08-2011 01:28 PM
110v porch light? Sheryl M Modifications, Alterations and Updates 19 05-06-2011 04:32 PM
Help! 12v interior light won't work Mo22 Electrical | Charging, Systems, Solar and Generators 12 06-07-2007 08:21 AM
boler 12v water pump and switch iaian pettit Plumbing | Systems and Fixtures 10 01-12-2007 01:07 PM
12v vs 110v power - what goes where in Scamp? TomN Care and Feeding of Molded Fiberglass Trailers 20 11-26-2005 11:51 AM

» Upcoming Events
No events scheduled in
the next 465 days.
» Virginia Campgrounds

Reviews provided by


Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -6. The time now is 12:56 AM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.