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Aussie Pinball Forums => Technical Matters => Handy hints and tips => Topic started by: Homepin on July 16, 2012, 11:29:14 AM

Title: Ever wonder why your OPTOs are failing??
Post by: Homepin on July 16, 2012, 11:29:14 AM

During some research for a project I stumbled upon a snippet of information in a Sharp Electronics datasheet that I have never seen before in the datasheets of any other brand BUT I'll bet the same applies to them all.

Optos are constructed from materials that degrade over time. That's probably not too surprising, BUT in the case of the Sharp datasheet advice, they 'can' lose 50% efficiency in only 5 years! WOW!

The sheet advises engineers to make allowances in their design for the falling efficiency of the device. I truly wonder if this advice was given to pinball designers 20 years ago or if they had any idea of how much the performance of these devices would degrade? I very much doubt it.

This could explain the myriad of 'mystery' problems we are seeing in pinball machines that are over 20 years old.….

My advice is to pay close attention to the opto devices in your machine if you start having 'weird' problems and if in doubt - replace them.

Here is the part from the Sharp datasheet (a company I trust):

(http://www.homepin.com/pics/optos.jpg)

Title: Re: Ever wonder why your OPTOs are failing??
Post by: goodolddays on July 16, 2012, 12:12:38 PM

Thanks for posting this very handy info Mike  ^^^

Title: Re: Ever wonder why your OPTOs are failing??
Post by: Pop Bumper Pete on July 16, 2012, 12:29:08 PM

Does that apply to today's optos, or just ones from 20 years ago?

Title: Re: Ever wonder why your OPTOs are failing??
Post by: Homepin on July 16, 2012, 12:38:28 PM

Quote from: Pop Bumper Pete on July 16, 2012, 12:29:08 PM

Does that apply to today's optos, or just ones from 20 years ago?

I would think that 20 years ago things were actually a lot worse and that the devices were not as good as modern ones so that would mean that the specs on devices used in our machines could be a LOT worse than the 50%/5 years quoted for modern parts.

Title: Re: Ever wonder why your OPTOs are failing??
Post by: GORGAR 1 on July 16, 2012, 03:38:01 PM

Interesting thanks

Peter

Title: Re: Ever wonder why your OPTOs are failing??
Post by: ajlaird on July 16, 2012, 08:22:41 PM

Nice bit of info dug up there!

Title: Re: Ever wonder why your OPTOs are failing??
Post by: elkor-alish on July 16, 2012, 09:48:32 PM

Please excuse the dumb question Mike, but does that mean five years of use or five years just sitting there?
I'm thinking of machines that have been in storage.

Title: Re: Ever wonder why your OPTOs are failing??
Post by: Homepin on July 16, 2012, 10:02:49 PM

Quote from: elkor-alish on July 16, 2012, 09:48:32 PM

Please excuse the dumb question Mike, but does that mean five years of use or five years just sitting there?
I'm thinking of machines that have been in storage.

I'm guessing it means five years of CONTINUOUS on state. Who knows really?

The interesting point I make is that this fact was well known to the manufacturers of the parts and very likely never passed on to anyone else  !@#

Title: Re: Ever wonder why your OPTOs are failing??
Post by: Strangeways on July 18, 2012, 10:13:15 AM

Pinballs were built to last 5-10 years. Their route days were not long, especially if they were poor earners. Makes sense for manufacturers to select parts that don't exceed a lifespan of 5-10 years.

Goo pick up Mike - Always interesting to read this kind of info  ^^^