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Ice Cold Beer / Zeke's peak Q

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lilshawn:

--- Quote from: Xiaou2 on August 03, 2012, 08:29:46 am ---Generally, Optics are subject to getting dirty... and thus cease to read properly.  They are not that hard to clean,
however, if they are buried in a machine, they tend to get ignored.

 However, in some cases, vibrations can crack soldier joints...  and or the optic just plain dies electronically.
Not sure if its due to voltage spikes... and or just that the beam sender / receivers just have a limited lifespan or hrs.

 Micros are actually very robust, many taking millions of activations before they fail.  Nothing to fail when not
being pressed either.


--- End quote ---

LED's are generally very poorly made now a days (not like they used to be) they still have a pretty high failure rate though. what actually happens is the infrared LEDs they use are driven pretty hard...something that could probably be eliminated by increasing the drive resistor size to bring down the mA...and they just plain old burn out.

it's a pain in the butt to diagnose if an opto is malfunctioning or not due to the fact you can't see it operating. usually your cellphone camera can shift the infrared far enough that you can see it.

SavannahLion:
Interesting information. I haven't considered that as a failure. Maybe I should take another look at using switches instead. That's going to be a pain though since I've kind of did the design towards optics, and more importantly, their size.

In any case, can anyone give me the rest of the hole sizes that are used in the non-scoring holes on the Taito version? I have 5/8" hole as being the scoring hole size.

And as an added bonus, just what is the size of the playfield? I'm guessing, based on photos and using the size of the ball as a known reference, somewhere under 25" wide and how tall....?

lilshawn:

--- Quote from: Xiaou2 on August 03, 2012, 06:10:08 pm ---Interesting.

 But, even if they were not driven too hard... According to 1 source I found,  said typical LEDs are rated for about 50,000hrs.   



--- End quote ---

(50000/24)/365 is still only 5.7 years. in the grand ole scope of things, that's f-all.


--- Quote from: SavannahLion on August 26, 2012, 02:29:30 am ---Interesting information. I haven't considered that as a failure. Maybe I should take another look at using switches instead. That's going to be a pain though since I've kind of did the design towards optics, and more importantly, their size.

In any case, can anyone give me the rest of the hole sizes that are used in the non-scoring holes on the Taito version? I have 5/8" hole as being the scoring hole size.

And as an added bonus, just what is the size of the playfield? I'm guessing, based on photos and using the size of the ball as a known reference, somewhere under 25" wide and how tall....?

--- End quote ---


I'll get some measurements on the original Taito ICB we have in the shop tomorrow if I get the chance.

SavannahLion:

--- Quote from: lilshawn on August 26, 2012, 07:40:43 pm ---
--- Quote from: Xiaou2 on August 03, 2012, 06:10:08 pm ---Interesting.

 But, even if they were not driven too hard... According to 1 source I found,  said typical LEDs are rated for about 50,000hrs.   



--- End quote ---

(50000/24)/365 is still only 5.7 years. in the grand ole scope of things, that's f-all.

--- End quote ---

You can cheat to some degree though. Don't run the LED's full on all the time. 1/2 duty cycle should extend their lives a bit. Your equipment isn't going to be on 24/7 so there's some savings there. My poor PC's fans died long before the LED's showed any signs of aging. To take it into context, the FLASH memory area of an Atmel microcontroller is only rated for twenty years.  :( At least an LED is easily replaceable.


--- Quote ---
--- Quote from: SavannahLion on August 26, 2012, 02:29:30 am ---Interesting information. I haven't considered that as a failure. Maybe I should take another look at using switches instead. That's going to be a pain though since I've kind of did the design towards optics, and more importantly, their size.

In any case, can anyone give me the rest of the hole sizes that are used in the non-scoring holes on the Taito version? I have 5/8" hole as being the scoring hole size.

And as an added bonus, just what is the size of the playfield? I'm guessing, based on photos and using the size of the ball as a known reference, somewhere under 25" wide and how tall....?

--- End quote ---


I'll get some measurements on the original Taito ICB we have in the shop tomorrow if I get the chance.

--- End quote ---

GREAT! THANKS! I'd appreciate that.

lilshawn:
you can try a system similar to what stern does with their optos in the newer machines. they have 2 superbright LED's  and shine the first LED at the second which is connected to a mosfet.

it exploits a little known fact about LED chips, in that they are sensitive to their particular frequency of light they emit. by shining the LED at another of the same, the second LED generates a tiny voltage. enough to trip a MOSFET to turn on and act as a switch.

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