1. Home
  2. Electronics Design
  3. Can tact switches be under permanent pressure?

Can tact switches be under permanent pressure?

Can simple tact switches be under permanent depression for days or weeks without some spring in there wearing out? This kind:

formatting link

I'd like to use them as end switches. The end switches on our Genie garage door openers contain those flimsy open metal contacts. Every few months a door bangs hard against a stop because the contacts are bad. Sand paper brings them back but I'd like to improve this. Thing is, one of the end switches will always be pressed. Which one depends on whether the door is open or closed.

Regular end switches aren't very easiy to fit into the little rider frames.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg
Loading thread data ...

Must be a really ancient Genie. They're junk. Replace with a Liftmaster. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

     Thinking outside the box... producing elegant solutions. 

"Imagination is more important than knowledge." 

"Long live impudence! It is my guardian angel in this world." 

"It is important to foster individuality, for only the individual 
can produce the new ideas." 

"A foolish faith in authority is the worst enemy of truth." 

                              -Albert Einstein
Reply to
Jim Thompson

s.

how much room do you have?

formatting link

1/dp/1961066
Reply to
Lasse Langwadt Christensen

Replace it with a reed switch and magnet. That is what is on the Genie I have. Never a problem.

Reply to
tom

+1

Or HE sensor, tuned coils, etc.

I use a long-throw iso-optilator to detect the actual position of our door (not the position that the opener *thinks* its in)

Reply to
Don Y

Don't do this, the switches won't last.

This type of switch (especially the smaller versions) is commonly used on mp3 players, and my experience with them so far was that they become defective when pressed continuously. A couple of years ago I used such a player for reading some texts. The small thing showed only about half a sentence on screen, so I kept pressing the "forward" key all the time.

Long story short, it wore out really fast. Especially if one has the (admittedly bad) habit of keeping it "half-pressed" and only slightly pushing it further for each press, the key breaks in no time. First it becomes "soft" (easy to press and no longer clicks) but still easily makes contact (sometimes too easily), than it becomes noticeably intermittent, and at the last it becomes very soft with no more tactile feedback, but hardly makes contact anymore (requiring lots of force and making contact only occasionally). Once the key has become noticeably soft, the rest follows quickly.

Reply to
Dimitrij Klingbeil

Those are around 1cm wide and tall, don't have that much. I have 5-6mm because I want to mount under the tongue.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

They work fine since 25+ year, except for those flimsy end switches. I am not about to throw it all in the trash and buy new lifters for $1000 because of a small fixable problem.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

Good idea but I'd have to measure what current the electronics on the older Genies draw on the contacts.

Ideally I'd like to make this all work with the pars I already have though, for sports.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

:-(

Thanks, Dimitrij. That was the news I needed but was hoping wouldn't come. So those tact switches are out then. I have some small (really small, must first check if current ok) Reed contacts like Tom suggested but that is going to be more mechanical work.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

Add a 0.1uF cap across the switches so a little current flows when they close to keep the contacts clean. Switching dry circuits can be flakey.

m
Reply to
makolber

With the current contacts that wouldn't help because they are totally open. They simply corrode and become dusty.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

More like $200 and easy to install yourself. I (at my advanced age :-) replaced two all by myself. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

             I'm looking for work... see my website. 

     Thinking outside the box... producing elegant solutions.
Reply to
Jim Thompson

We have two wide and very heavy steel doors. The usual 1/2 horse deal would have a hard time or be very slow.

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

My doors have counterbalancing springs so you can easily open/close by hand in case of a power failure.

(I note that some brands of openers now feature UPS, so no issues with power failure.) ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

             I'm looking for work... see my website. 

     Thinking outside the box... producing elegant solutions.
Reply to
Jim Thompson

Right. Installing a new opener *is* "a small fixable problem". It's often a little more complicated if there isn't already one installed but replacing them is trivial.

Reply to
krw

Same here but the mass of the door is so large that accelerating can trigger the overload cut-out in smaller drive units. The unit thinks the door is blocked or hit something. These steel doors were made in the

60's when stuff was still thick and solid. Sized for the kind of car the first owners preferred:

formatting link
'68_Buick_Electra_%28Auto_classique_St-Bruno-De-Montarville_VAQ_'13%29.JPG

A neighbor came running over during one of our infamous "gray-outs" around the year 2001. "I can't get the car out of the garage because there is no power but must leave!"

So I went over there, inside, ka-klock, rolled up door, jaws dropped. "Ahm, well, wonderful, thanks, but how do we close it again now?" ... rumble..rumble..rumble ... thud ... *PA-TOCK* ..."Oh!"

--
Regards, Joerg 

http://www.analogconsultants.com/
Reply to
Joerg

No! Trouble is when the contacts close on even 0.1uF the current is not little - it is brief but many amperes and can seriously wound contacts and instantly kill by welding delicate reed contacts. Much better to have a few ohms to few tens of ohms in series with that capacitor. Ask me how I learnt this :)

piglet

Reply to
piglet

I agree with you re reed contacts, I would NOT put a 0.1uF across reed contacts without the series R. m

Reply to
makolber

One would assume that Joerg is an EE and could cope with rolling an optical solution ?>:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| STV, Queen Creek, AZ 85142    Skype: skypeanalog |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 

             I'm looking for work... see my website. 

     Thinking outside the box... producing elegant solutions.
Reply to
Jim Thompson

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.