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Roof light switch?

FallibleXJ

FallibleXJ

NAXJA Forum User
Location
Rochester, NY
Quick question here, I currently have 2 switches to control my 4 roof lights. There is one that controls the relay for the outer pair, and one that controls the inner pair. I would like to consolidate these into one toggle switch that has 4 positions (off, outer, inner, all). However, I have been searching around the internet and have yet to find the switch for what I want. Anyone done this or know what kind of switch I would need.
 
Hmmm... I could give you a schematic to do that with a rotary but you want a toggle. Let me see if I can figure out how to get a 4-position dual throw slide switch to work for that with a few diodes, the problem is most 4-position slide switches don't have an actual common terminal, they connect different sets of 2 terminals for each position.

EDIT: this is the switch you want (hopefully it is a style you like, it's the only one I could find that'll fit from digikey... will check other distributors) http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=SW120-ND

Circuit coming soon
 
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yea, thats what I was noticing
 
Here's the circuit:
drivinglightsswitchfall.png

The two diodes are fairly generic, you can use normal 1N400x series rectifiers (1N4001, 4002 etc) from radio shack's bulk rectifier assortment pack without a problem. The switch can be any dual throw 4 position slide switch you like the look of, light positions from the top are OFF, OUTER, INNER, ALL. This circuit should definitely be used with relays (as you already are) or only very weak lamps with less than an amp of current draw.

Good luck!

EDIT: I may have overthought this, now considering whether the diodes can be replaced with pieces of wire or not. I think they can but I'm not sure.

EDIT2: yeah, just replace the diodes with pieces of wire in that diagram, I'm uploading a fixed schematic now

Updated schematic (wire colors are just for differentiation, the black wires are power to the relay coils):
drivinglightsswitchfall.png
 
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Inner only is the second position from the bottom - check how the wiring on the lefthand column of contacts works out. There is a slide contact that goes down each side - i.e. in the top position, the top two left terminals will be shorted and the top two right terminals will be shorted.
 
I'll give it a go! thanks much.

Out of curiosity, why the change to no diodes?
 
Costs less, works just as well (for some reason I was thinking like I was wiring up an AC fan for multispeed operation, or using a single-throw switch instead of a dual-throw. Either of these would require more diodes and/or more care in designing), and is less likely to be assembled wrong (wires go in either way, diodes don't!)
 
So thats how those things work. I went through school for electrical engineering and now I finally know how these switches work. NAXJA > College
 
kastein said:
Costs less, works just as well (for some reason I was thinking like I was wiring up an AC fan for multispeed operation, or using a single-throw switch instead of a dual-throw. Either of these would require more diodes and/or more care in designing), and is less likely to be assembled wrong (wires go in either way, diodes don't!)
Click to expand...

Don't forget the resistors... always check the polarity of your resistors. :laugh3:
 
haha yeah, I am an electrical engineer too... currently do mostly computer engineering stuff for my employer, but automotive electronics, embedded systems, RF electronics, and home electrical are some of my hobbies (aside from wrenching on my Heep.)

I always used to hate those switches because they don't have the easy "this is the input and these are the outputs" type of logic to them, they're obnoxious to think about till you get used to it.

themangeraaad said:
Don't forget the resistors... always check the polarity of your resistors. :laugh3:
Click to expand...
:roflmao: yeah, the tolerance band absolutely MUST point west
 
kastein said:
haha yeah, I am an electrical engineer too... currently do mostly computer engineering stuff for my employer, but automotive electronics, embedded systems, RF electronics, and home electrical are some of my hobbies (aside from wrenching on my Heep.)
Click to expand...

I actually went through for computer/electrical, and one hobby I wish I didn't have to give up was VHDL and low level programming/microcontroller work. I would love to keep doing it and could make some badass stuff for the Jeep. Light setups, digital dash, etc etc etc.. but the equipment to get into a hobby like that is... how should I put it.. out of my price range? :dunce: I would love to sit back and have a EPROM programmer available to me. I'm still kinda tempted to move back across the state to western MA where I went to school. Then I could stop in and use the labs there whenever i wanted and use the equipment (and chips) for free :D

kastein said:
I always used to hate those switches because they don't have the easy "this is the input and these are the outputs" type of logic to them, they're obnoxious to think about till you get used to it.
Click to expand...
Yeah, kinda, but once you understand how htey work they are simple. When I saw the first post I was thinking about digital logic.. still thinking about it actually. Thinking that I should wire in some logical OR and AND gates to make it so that in order to start my Jeep the headlights and one of the kill switches have to be on but the radio cannot be on etc.etc. I only think of that because I am thinking of wiring a push button ignition and half the time I have no doors. That and I am bored at work so I think of crazy pointless stuff.
 
Honestly, I had no clue how those kinda of switches worked. Kastein just taught me in under a minute of reading haha.
 
I think I learned that at age 9 when I tried to pull one out of an old TV to use for a project and managed to break it open by accident...

themangeraaad, I have a huge stock of 27Cxxx EPROMs and an EPROM burner (an old BPMicro 1140) that'll work as soon as I bother to get a win2k box running for it. If you need stuff burned send me binary images and part numbers and I can do it when I'm bored.

Almost all of the stuff I use for random electronics projects I got out of old junk I picked up in the last fifteen years or so - it's really ultra cheap if you know where to look. I'm actually looking at building a neat little switching module that'll let me use my OEM instrument cluster temp gauge to also monitor the input/output fluid temps of my transmission, and possibly becoming a vendor and selling them here, but I haven't quite gotten bored enough to finish designing the state machines required yet.

I've been meaning to do a huge writeup on relay wiring, electronics etc to put here but I haven't quite found the motivation yet... maybe weekend after next or something.

EDIT: on the EPROM stock - I have the most of 27C512s (got a case of at least two or three hundred, brand new, in stock tubes still, on craigslist, for... free) but I also have a pretty big stack of 27C010s, 27C256s, and 27C128s. Below that stock is a little sparse.
 
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kastein said:
I think I learned that at age 9 when I tried to pull one out of an old TV to use for a project and managed to break it open by accident...

themangeraaad, I have a huge stock of 27Cxxx EPROMs and an EPROM burner (an old BPMicro 1140) that'll work as soon as I bother to get a win2k box running for it. If you need stuff burned send me binary images and part numbers and I can do it when I'm bored.

Almost all of the stuff I use for random electronics projects I got out of old junk I picked up in the last fifteen years or so - it's really ultra cheap if you know where to look. I'm actually looking at building a neat little switching module that'll let me use my OEM instrument cluster temp gauge to also monitor the input/output fluid temps of my transmission, and possibly becoming a vendor and selling them here, but I haven't quite gotten bored enough to finish designing the state machines required yet.

I've been meaning to do a huge writeup on relay wiring, electronics etc to put here but I haven't quite found the motivation yet... maybe weekend after next or something.

EDIT: on the EPROM stock - I have the most of 27C512s (got a case of at least two or three hundred, brand new, in stock tubes still, on craigslist, for... free) but I also have a pretty big stack of 27C010s, 27C256s, and 27C128s. Below that stock is a little sparse.
Click to expand...

You've peaked my interest, Good Luck!
 
I am leaving work early to pick up a sheet of steel or two and I am making a custom headlined. Installing my radio head unit from the roof so I cna put the CB in the dash. Trying to figure out something digital gauges to put up there as well, but then I woudl have to write the code and such... I suppose I am too lazy some of the time (I guess I am the same way.. I will get it done when I am bored, but for the time being I have certain projects planned and cant motivate myself to do anything other than those :laugh:
 
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