normally-closed, Push Button, where to buy it?

[skydiverMN]

Looking for recommendations for a high quality (but not high cost) normally closed push button that will handle the output from a 24v AC transformer.

I've found lots of places that sell NC push buttons, but I have no idea what manufacturers are good. This will be used in a protected but unheated environment and needs to be able to handle Midwest winter temperatures without binding up. Sure, Radio Shack sells something like this but I don't trust the quality of their stuff for this application. Point me in the right direction! I appreciate your help!

Thanks!

 

[(*steve*)]

What current are you switching and what is the load?

 

[skydiverMN]

now you've got me....

While I'm a good DIYer, I'm not an electronics guy. Sure, I have experience wiring and building small stuff, but I don't really know the math that's involved when designing a circuit.

Here's what I'm doing:
I am attempting to create a DIY garage door open indicator. As a guide, I'm using this:
DIY Indicator

I already have the transformer, but I plan on having 2 LEDs and about 100' of 18 gauge wire. I already have a bunch of different resistors, and was simply going to wire up a few and see what kind of voltages I get. Sure, there's an easier method but I thought people here could help. Radio Shack is fine for projects, but I'd like something higher quality seeing this is pretty important. I found this for a switch, and it's very high quality from what I can tell: push button switch. Cost for shipping the switch is more than the switch itself, though.

So, now you know what I'm dealing with! Thanks for your time!

 

[jackorocko]

You said the button would be outdoors, but that link you provided shows the button mounted inside.

I highly doubt you need a very high quality momentary push button. Your current and voltage requirements are very low as well. I would look on digikey or mouser for a standard momentary push button and would advice you to find a way to mount it indoors like the link you provided. It will last for years. Cold itself will not cause the button to stop functioning, but moisture and dirt will. Just like it will for anything else.

 

[skydiverMN]

thanks!

Outdoors, yeah. Kinda. In my garage, specifically. I thought that the cold temp of the inside of the garage during winter warranted getting an outdoor switch. But seeing it's moisture that'll damage it, and it'll be fully covered/protected, I'll just check out the places you're talking about.

Thanks for the time!

 

[(*steve*)]

I would recommend you look at some lever operated microswitches.

The reason I suggest this is that the actuating lever can withstand being "banged" by the door.

I would imagine a switch mounted as shown there could rely on the door closing to an exact point. If it goes a few mm further, the button becomes an end stop (which may destroy the button). A few mm in the other direction and the button may not be actuated (leading to a false alarm)

They look like this:

(actually they come in a wide variety of shapes and sizes, but this is the style I would recommend.)

Where are you? Knowing that, I may be able to make some general recommendations but if we have a member in your neck of the woods you may bet something more specific.

Something like this is what I'd be recommending. It has a long lever so it's easier to cater for a little slop in the final position of the door.

 

[skydiverMN]

good idea

To protect the switch (some only depress .15" or less) from getting crunched, I was going to have a 'finger' piece of bent sheet metal. This would allow the button to be pressed indirectly, and the bend would allow the finger to act as a shock absorber to handle most of the force. This way I'm guaranteed sufficient contact without damanging the switch. It'll require some finesse to get the placement aligned and the bend correct, but I think that this would work fine.

Not sure when I'm going to start, but I'll take some pictures when it's up and running.

Thanks!

 

[MBVet05]

I suggest using Digikey for most of your electronic component needs.

 

[skydiverMN]

math? Different LEDs in the same series circuit

I have found several websites that allow me to plug in the values of my circuit (supply V, LED V and current, etc), but these are all for LEDs of the same type. As with everything, I seem to make things much more complicated than I probably need to. What I want to do is use one LED that blinks (2.5-5v, 80mA), and another that just lights up (1.7v, 28mA). So, now I need to determine the resistor when these are wired in series.

Is it just not a good idea to use different LEDs in the same circuit? I don't NEED to do this, but I thought it would cool to have the blinking one...

My transformer can produce these values:
8v 10VA
16v 10VA
24v 20VA

Can anyone point me in the right direction to determine the math?

Thanks!

 

[(*steve*)]

Lots of information about using LEDs here.

 

[skydiverMN]

Thanks for all the help. I've read the LED stuff and have begun to play around with a few different LEDs... I'll start another thread to ask my specific questions. Thanks again!