End of an (electrical) era

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Just about every HP printer has one of these slotted optical sensors. Basically a pair of LEDs. Some of the print heads have a more complex one.
That stuff is really not expensive e.g. a TCST2103. Salvaging them from old printers can be frustrating, LEDs burn ( 🔥💥) with wrong current, pinout is sometimes not clear. Extracting them from an old device is extra work.
I doubt that making the light barrier mechanically work is less hassle than fitting a hall sensor :cool: The automotive people seem to have settled on the Hall sensors.
 
That stuff is really not expensive e.g. a TCST2103. Salvaging them from old printers can be frustrating, LEDs burn ( 🔥💥) with wrong current, pinout is sometimes not clear. Extracting them from an old device is extra work.
I doubt that making the light barrier mechanically work is less hassle than fitting a hall sensor :cool: The automotive people seem to have settled on the Hall sensors.
Hi Timo,

I've never had any problems extracting dual or single opto devices from scrap equipment. I use a hot air paint stripper gun. Aim the hot air at the solder side !
However I have noticed that the lead free solder is a lot harder to melt.
 

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Not impressed. Tried using 9V smoke detector battery and the spark only discernible by a slight click. Very weak visible spark at 9V. They are supposed to be 6 - 12V so will probably be only OK with 12V.
 
For the cost of a spark generator off ebay at less than $10 you may as well just buy one of those. No hall sensors to go wrong. And it's a buzz type rather than a single spark

Simple 4 wires - Positive, Negative/ground, sparkplug and the last wire just needs simple make and break contact to ground. Seen here just as a wire touching a revolving contact.


I received one of these a while back and finally got around to trying it. There is no doubt that it puts out a powerful spark and if you get in the way it really grabs you attention. My problem seems to be that it is too good. The spark will jump a good 1/2". When I wire everything up I have sparks flying all over the place to any metal part within 1/2". I am wondering if I have wired it wrong. I have 6 volt power into the red+ and white- on what I would assume is the input end. I have the large wire going to the spark plug and I am using the white wire on that end as the trigger. Am I wiring that wrong? Your setup does not seem to be throwing sparks to everything in the area.
 
Sometimes on Ali they show the photo and image of the most expensive option but the price of the least expensive. You have to make sure you select the actual item you want and then the price will likely go up as well. For example you may see an image of a vice fot $10. But the $10 is actually just the option of some vice jaws. Select the actual vice and that will be $100.

Red wire Positive to battery
White wire that is next to the red is the insulated contact
Thick HT wire obviously to plug
White wire next to that ground to engine frame
Engine frame also connected to the negative battery
 
Sometimes on Ali they show the photo and image of the most expensive option but the price of the least expensive. You have to make sure you select the actual item you want and then the price will likely go up as well. For example you may see an image of a vice fot $10. But the $10 is actually just the option of some vice jaws. Select the actual vice and that will be $100.
That's annoying but it happens on Ebay, too. I was looking at some cheap crucibles on Ali, at $6 .... and $35 freight(Canadian prices). No, I wasn't expecting that kind of price and I do little casting so wasn't expecting the best quality either.
 
I ordered one of these based on recommendations from here. Came from Ali-Express but only received a spark plug!

Anyone else had a problem or another more reliable source??
Did you select the item on the order page. There is a choice of items. I wouldn't recommend the small unit I mentioned as it has a very weak spark.
 
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