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Optical Buttons?

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stevejt:

I was not "concerned".  I was just stating I don't see any benefit.  As far as doing it just because it hasn't been done, I think that's awesome.  I just thougt it silly (I'm sure I do many (many, many) things the rest of the world sees as silly), to go through the manufacture of a control panel worth of buttons, without having any benefit. 


--- Quote ---If you haven't built optical buttons then I seriously doubt your ability to judge their practical characteristics. 
--- End quote ---
Unless I am missing something, you haven't YET either.  So if your statement is true, than you don't have any ability to judge their pratical characteristics either.   ;D  (You don't need to be shot to know it's gonna hurt.)

question: you said analog measurements from the photo transistor.  My knowledge of electronics is basic.  I know the measurements from a CDS cell are varible, (and I know, designed mainly for visible light).  I thought infrared detectors were more towards the digital side.  Is a photo transistor exactly the same as an infrared detector?  I am asking because transistors give variable readings, but have 3 leads.  Infrared detectors have 2 leads.  (Wheel sensors have 3 leads for 2 sensors for sensing direction.) This is an honest question, since you seem to have knowledge on the subject.

I never said, or even hinted that it couldn't be done.  I just said extra work, extra wires, extra voltage, more parts to fail, with no BENEFITS.  As leafs are reliable.  Though some work, micro switches can be quieted by opening them, and bending the contact,(in the right spot) to lower the distance of travel the contact makes when the "snap" is made.  Something could also be put between the NC contacts, that would leave less distance between the NO's. 

If you complete this, which mechanically I do think is simple, I am sure everyone, INCLUDING MYSELF, would love to see some close up pics.  I am sorry if I still don't see any benefits outweighing the extras.

(BYW-  my reply seemed to piss you off some,(even if just a little), it was nice to see such a strong response, not be rude.  What I call a "polite STFU".

Steve




tetsujin:


--- Quote from: stevejt on February 02, 2005, 09:33:45 am ---question: you said analog measurements from the photo transistor.  My knowledge of electronics is basic.  I know the measurements from a CDS cell are varible, (and I know, designed mainly for visible light).  I thought infrared detectors were more towards the digital side.  Is a photo transistor exactly the same as an infrared detector?  I am asking because transistors give variable readings, but have 3 leads.  Infrared detectors have 2 leads.  (Wheel sensors have 3 leads for 2 sensors for sensing direction.)
--- End quote ---

I should really try not to get so pissed off all the time.  :)  I've got to remember why I'm here talking to knowledgable, experienced people instead of doing my work in total isolation.

In fact, now that you mention it, it is possible that it wouldn't be possible to take analog readings from the phototransistor in an opto-interruptor module.  Different transistors have different characteristics, and some are less inclined toward analog behavior than others.

The reason phototransistors generally have two leads instead of three is because the third is replaced by the optical sensor.

The IR sensors in most IR equipment are, I think, generally IR phototransistors.  Certainly the ones I was looking at at All Electronics are, according to the spec sheets.

stevejt:


--- Quote from: tetsujin on February 02, 2005, 10:12:42 am ---Different transistors have different characteristics, and some are less inclined toward analog behavior than others.

The reason phototransistors generally have two leads instead of three is because the third is replaced by the optical sensor.


--- End quote ---

Thanks.  Well explained.

I'm sure your "polite stfu" must have entertained a few.  As much as they were inapropriate, Subzero's immature comments and arguments were at the very least, entertaining.  I actually feel bad to be the one he was arguing with when he finally got banned.  But I guess it was coming to him anyway. 

Steve

This reminds me of BBSing.  When some boards had the "war zone" thread.  Gotta love that!
Any one who doesn't know what I'm talking about, you missed out!






NoOne=NBA=:

The key here is to think of this as a brainstorming environment.
You throw out a "what if', and people respond with "but, but, why not...".

From that you pick what helps YOU, and ignore the rest; or respond back with your own "but, but, why nots...".

If you think of the board here as a big swirling pool of knowledge, experience, and mistakes, it will help keep you on a little more even keel.

Alot of people here have tried ideas that you might have; and will try to talk you out of doing things, or into doing them a simpler way, because they've made mistakes doing what you are attempting.
If you look past the "don't do its", and concentrate on the "here's what I did wrongs", you may be able to succeed where they failed.
If you decide to "do it anyway", at least you were forewarned.

Alot of times people here will just play Devil's Advocate in threads to help the person think things through before starting, and presolve as many problems as possible without wasting time/money.
That's the case in most of this thread.
People are all shooting out ideas, actually related to different goals (analog/digital/optical/mechanical/etc...).
YOU need to pick the knowledge out of it that helps you succeed in whatever you attempt, and retain the rest for future reference to whatever extent possible.

ShinAce:

Stay tuned....
In a few weeks time, I'll have built such a beast.

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