View Full Version : Two electrical questions: bulb & toggle switch
taoplr
Mar 21, 2010, 10:36 PM
Hi,
1- If a light fixture has a label that says "don't use anything larger than a 60 watt bulb," which I presume is about heat generated by an incandescent bulb, is it safe to use a new, energy saver 100 watt fluorescent bulb that is labeled to only use 25 or so watts? I'm assuming that the new bulb puts out a lot less heat.
2 -I'm fixing a 12 volt quartz halogen desk lamp and have to replace the on-off toggle switch. It is small, and the only replacements available are "on-on" switches. The sales guy at Fry's told me to just cut off the third terminal (the connection to the second "on.") and that position will become the "off" position. Is this correct? Is this the standard way these things are done?
Thanks
Tao
WallyHelps
Mar 22, 2010, 04:55 AM
1- Since the CF bulb really only uses 25 watts or so you should be fine. You can think of watts as a measurement of heat, and not really a measurement of light output. So the CF bulb puts out the heat of a 25 watt incandescent, while giving the light output of a 100 watt incandescent.
2- What the Fry's guy told you is okay. Internally, the switch would look something like the diagram attached. If you cut off one side--or just leave it unconnected--it will do what you want. If the switch has wires already attached, then I would just clip one of the two outer wires as short as possible. You might want to hook everything up before clipping anything, however!
Hope this helps,
WallyH
taoplr
Mar 22, 2010, 09:45 AM
1- Since the CF bulb really only uses 25 watts or so you should be fine. You can think of watts as a measurement of heat, and not really a measurement of light output. So the CF bulb puts out the heat of a 25 watt incandescent, while giving the light output of a 100 watt incandescent.
2- What the Fry's guy told you is okay. Internally, the switch would look something like the diagram attached. If you cut off one side--or just leave it unconnected--it will do what you want. If the switch has wires already attached, then I would just clip one of the two outer wires as short as possible. You might want to hook everything up before clipping anything, however!
Hope this helps,
WallyH
Thanks, Wally. These are solid answers.
I repaired two other lamps with the same switch problem; but with this one, I got solder all over the place and decided to replace the switch. If I could find a replacement 2-prong (halogen bulb pins) socket the right size and shape (round), I'd replace the whole thing. But your input helps me do with what I have.
Thanks again,
Tao
taoplr
Mar 22, 2010, 09:47 AM
1- Since the CF bulb really only uses 25 watts or so you should be fine. You can think of watts as a measurement of heat, and not really a measurement of light output. So the CF bulb puts out the heat of a 25 watt incandescent, while giving the light output of a 100 watt incandescent.
2- What the Fry's guy told you is okay. Internally, the switch would look something like the diagram attached. If you cut off one side--or just leave it unconnected--it will do what you want. If the switch has wires already attached, then I would just clip one of the two outer wires as short as possible. You might want to hook everything up before clipping anything, however!
Hope this helps,
WallyH
Excellent
taoplr
Mar 22, 2010, 09:48 AM
1- Since the CF bulb really only uses 25 watts or so you should be fine. You can think of watts as a measurement of heat, and not really a measurement of light output. So the CF bulb puts out the heat of a 25 watt incandescent, while giving the light output of a 100 watt incandescent.
2- What the Fry's guy told you is okay. Internally, the switch would look something like the diagram attached. If you cut off one side--or just leave it unconnected--it will do what you want. If the switch has wires already attached, then I would just clip one of the two outer wires as short as possible. You might want to hook everything up before clipping anything, however!
Hope this helps,
WallyH
I should know how to rate an answer by now!
KISS
Mar 22, 2010, 12:18 PM
1. Answer is fine
#2. Needs some clarification. The correct terminology is a ON-none-ON toggle switch. An ON-OFF-ON would have 3 positions. An (ON)-OFF-ON would also have 3 with one a momentary one.
SPST or DPST or DPDT are single pole single throw. You can also have DPDT or DPDT center off switches which is the same as a double pole ON-OFF-ON switch. There are lots of variations like DPST, 3PDT etc.
Usually the terminal that you need to remove would be the end terminal opposite the position of the toggle. Think of the handle as an extension.
Many switches used for appliances like lamps have wire leads and a hardware store is a good place to get these. A toggle switch with wire leads is located here: Error Handler (http://www.grandbrass.com/search.cfm). Search for switch.
Yep, you can solder wires and insulate the soldered terminals with heat shrink tubing.
Remember to get a switch rated for the load.
taoplr
Mar 22, 2010, 03:37 PM
1. Answer is fine
Thanks
#2. Needs some clarification. The correct terminology is a ON-none-ON toggle switch. An ON-OFF-ON would have 3 positions. An (ON)-OFF-ON would also have 3 with one a momentary one.
SPST or DPST or DPDT are single pole single throw. You can also have DPDT or DPDT center off switches which is the same as a double pole ON-OFF-ON switch. There are lots of variations like DPST, 3PDT etc.
Usually the terminal that you need to remove would be the end terminal opposite the position of the toggle. Think of the handle as an extension.
Many switches used for appliances like lamps have wire leads and a hardware store is a good place to get these. A toggle switch with wire leads is located here: Error Handler (http://www.grandbrass.com/search.cfm). Search for switch.
Yep, you can solder wires and insulate the soldered terminals with heat shrink tubing.
Remember to get a switch rated for the load.
The switch I got is here:
FRYS.com | GC ELECT. 35-008 (http://www.frys.com/product/2860434?site=sr:SEARCH:MAIN_RSLT_PG)
It's a Single Pole Double Throw (which I interpret to mean One On-Off Polarity and two possible options about how the switch is wired and thrown) with three terminals at the bottom. So if I cut off one of the terminals, it becomes a Single Throw switch. Is this correct?
On the question of the heat-shrink tubing, the wire is high temperature rated (I am told) and is a single strand (not multiple, woven strands) with a woven insulation/skin on it. Because I dumped too much solder on the connections the first time I tried fixing this, I stuffed electrical tape between the almost-touching connections.
This seemed foolish on afterthought, so I went looking for a replacement, got finer solder, etc. and will redo my work.
One last question: This is a high-heat halogen lamp. Is typical heat-shrink tubing effective as an insulator in this situation? I will work to keep things from contacting each other and shorting out, but a little backup would be nice.
KISS
Mar 22, 2010, 04:28 PM
That's a SPDT momentary on switch. Wrong one for the application. You really don't have to cut the terminal off. Just don't use it.
You can get Teflon heat shrink tubing which would be better. e.g. Digi-Key (http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=HSTTT15-48-Q-NDhttp://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=HSTTT15-48-Q-ND) which hasa 2:1 shrink ratio.
The typical polyolifin (spelling) tends to get hard under high heat conditions.
I get the idea that you may not be soldering properly. Attach the wire. Bend it around. Heat the terminal and apply solder on the opposite side of the iron on the terminal. Cut off the excess wire.
20/20 Hindsight says put the heat shrink on first away from the soldered connection.