need basic help with wiring 4

[schauspieler]

Hi there! I'm very new to this website even though I've been a member from some time. I have a very basic question. I have a simple project of connecting two sets of LEDs (one red and one green) with a simple switch. My goal is to have a button that effectively switches between green and red. Is a 3 way switch (on-off-on) what i need and what is the desired wiring that i would need? I plan to use the same power supply for both lines (green and red) with the switch allowing me to change which line is active. I apologize if the question sounds retarded but I'm really new to this field so any help would be much appreciated. Thanks in advance

 

[Noway2]

My goal is to have a button that effectively switches ... Is a 3 way switch (on-off-on) what i need and what is the desired wiring that i would need?

While you may be able to get a button that acts as a 3 way switch, at the most basic you would be looking for something like a SPDT switch which would let you select between the two outputs. As an example, you would ground the cathode of the LEDs and supply +V to the common of the switch and put a current limiting resistor on each switch output. You could also use something like a toggle relay or a T-flip-flop. Similarly, there are lots of other digital circuits you could come up with that would do the same thing. You might like the site Discover Circuits, which has LOTS of sample schematic and project ideas.

 

[MikeHalloran]

Do use a power supply with current limiting, or a fuse or a circuit breaker on the secondary side. If you don't understand that, get local help.


Mike Halloran
Pembroke Pines, FL, USA

 

[DRWeig]

I felt like sketching. Click HERE.

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

 

[jraef]

Technically, he didn't say he needed an Off position, and technically, a standard SPDT switch would be only 2 positions, so that would work as shown but the lights would always be either green or red, no Off (unless that was done elsewhere).

Getting the center Off position in the middle changes the designation of the switch style to SPTT (Single Pole Triple Throw), or also known by SPCO (Single Pole Center Off) and SPTTco.

"Will work for (the memory of) salami"

 

[itsmoked]

Ha! Never heard those terms before Jeff. I've always seen that listed as an ON-OFF-ON as compared to, say. an SPST switch which is often called an ON-OFF.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[ScottyUK]

Over here SPCO is usually an acronym for Single Pole, Change-Over which is equivalent to SPDT above.

 

[LionelHutz]

I always see the double throw notation used to meant the switch is off in the center and can be thrown either direction, hence double throw. There is enough ambiguity in that description that other configurations like no off or no off and spring return to one position could also be described as DPDT.

 

[waross]

SPST, Single pole, single throw. The off position is implied.
SPDT, Single pole double throw. The off position is implied.
The notations are often used together.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[DRWeig]

I don't think that off position is implied on a double-throw. Contact form and switch function have to be separate items (SPST being the exception). Here's how I spec 'em, just to be certain I get what I want:

For a center-off switch:

Contact Form: SPDT
Switch Action: On-Off-On

For a toggle without a center-off position:

Contact Form: SPDT
Switch Action: On-On

I got that method from Mouser and Digi-Key. (Click the company names for examples).

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

 

[itsmoked]

Yep Dave.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Old school: SPST, SPDT, DPST, DPDT, Three way switch, and four way switch. But I agree, Dave and Keith, when spec'ing or purchasing, go with the suppliers format.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[jraef]

I was in the toggle switch business years ago.

For the doubters... click here



"Will work for (the memory of) salami"

 

[waross]

Thanks Jeff. I am suitably contrite.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[DRWeig]

Augh! Jeff, I've never been on the receiving end of one of those but I earned it too.

I thought about triple-throw would be a good term, but I didn't bother...

Best to you,

Goober Dave

Haven't see the forum policies? Do so now: Forum Policies

 

[stevenal]

I clicked the link, and the first two hits disagree with each other. Wikipedia says SPTT has a stable off position, Amazon says on/on/on. No consensus with lmgtfy.