I can buy a red laser pointer for $3. A green laser pointer for $7. I can buy red laser modules on ebay for these type of pens from China for $2.50 in bulk. I can't find green ones in bulk, but they run around $10.
Yet when I search sites like Digikey, modules which look identical to the ones from China are hideously expensive in comparison, even when purchased in bulk. Maybe the ratings of 5mW on ebay are a lie, but the cheapest 2.5mW laser module on Digikey is still $8 even if I buy 100: http://dkc3.digikey.com/PDF/US2011/P2811.pdf
It makes me wonder how these guys can stay in business. I mean who would spend $100 on a green laser module designed for a laser pointer, with less than 5mW of output power, when a laser pointer of the same power can be had on amazon for $10?
But anyway, I'm wondering if anyone knows where I can find these things cheap and in bulk other than ebay? (By bulk I mean in quanities of say, 100.)
The "expensive" laser pointers actually have a "proper" laser diode in them, with at least a colimating lens.
I had a friend pick up some dodgy ones in Singapore, when I took them apart the laser "diode" was a crystal looking thing, sandwiched between 2 copper plates.
The beam quality was terrible, it drew 3 times the current, got more than a "tad" warmish and I'm still surprised they even work!
Cheap green and blue laser pointer units can output a lot of infra-red (in other words the frequency-doubling/trebling crystal isn't working efficiently). They will also be less reliable. Simple equation, cheap = corners cut.
Most of the cheap, low wattage, LASER pointer modules, from China (where you'll find most come from), are just as good as anything that you'll find offered by the large parts houses (like DigiKey). They are so much cheaper because, labor is much cheaper there, raw materials are much cheaper there, the Chineese government subsidizes the export industries to build up it's world economic position. The quality control was an issue not too long ago, but that is getting better as time goes along. Where do you think DigiKey is getting thier modules?? They don't make them thierselves.
Check out Laser Pointer Forum for more info.
And the above caution about DPSS modulea blasting out IR is very correct! But, if you want low power Reds, no sweat, no danger.
Where do you think DigiKey is getting thier modules?? They don't make them thierselves.
Yes, but they don't make anything they sell and it's not all priced far higher than other sources.
And the above caution about DPSS modulea blasting out IR is very correct!
Wouldn't you have to shine the laser in your eye for this to be a danger? And wouldn't most people look away if a green laser were shown in their eye regardless of whether there were an infrared component to the beam?
Not just a direct hit to the eye, but also incidental (reflection) exposure. Depending upon appearant brightness, maybe yes,maybe no.... and the harmfull part is I.R. (beyond the visable range for humans), so, NO BLINK REFLEX until thermal damage is noticible (and already done)....
The cheap, low power, DPSS are most hazardous when there is a direct hit, true. but the other exposure hazards need to be paid attention to also.
One reason for price difference may be the inclusion of reasonablly good I.R. filtering.
One reason for price difference may be the inclusion of reasonablly good I.R. filtering.
Probably the big difference in pricing is that the digikey components may be made to higher tolerences with better materials with tested and known performance. A certified spark plug for an aircraft engine is going to cost 10x the cost of a standard car engine spark plug, even thought they appear the same to the casual observer. The same with lasers.
Because when you buy from a reputable source you are getting exactly what you orderred. That is why they are a reputable source. When you buy from Sam Wong in china you have no idea what you are getting. In the US you are also paying for some lawyer because the manufacturer and the distributor have to protect themselves from morons who hurt them selves using this stuff when they don't know what they are doing.
I'd be willing to bet that there is little to no difference in quality or anything else between the part for China/Ebay and the one from Digikey; in fact, Digikey probably buys from the same supplier. Why the price diff then? Probably because you can easily return the part if it doesn't meet your spec or other needs (good luck with doing that via China/Ebay), and also because they are relying on your FUD response to think they are more "reputable" because of that. Ultimately, though, you should just buy a certain percentage more number of parts for China, call it "overage due to failed parts", take any losses out on your taxes (if there are any) as part of doing the business (what do you think Digikey does with their returns?), and get over your FUD. Nowadays, you'll find few electronic components (or much of anything else it feels like, sometimes) manufactured here in the USA, let alone the west; all of that manufacturing has moved to Asia and China. It is unlikely to return to the west in the near future.
cr0sh:
I'd be willing to bet that there is little to no difference in quality or anything else between the part for China/Ebay and the one from Digikey; in fact, Digikey probably buys from the same supplier. Why the price diff then? Probably because you can easily return the part if it doesn't meet your spec or other needs (good luck with doing that via China/Ebay), and also because they are relying on your FUD response to think they are more "reputable" because of that. Ultimately, though, you should just buy a certain percentage more number of parts for China, call it "overage due to failed parts", take any losses out on your taxes (if there are any) as part of doing the business (what do you think Digikey does with their returns?), and get over your FUD. Nowadays, you'll find few electronic components (or much of anything else it feels like, sometimes) manufactured here in the USA, let alone the west; all of that manufacturing has moved to Asia and China. It is unlikely to return to the west in the near future.
Guess you purchase you medicine cheap from "on line" pharmacys instead of the local drug store.
cr0sh:
I'd be willing to bet that there is little to no difference in quality or anything else between the part for China/Ebay and the one from Digikey; in fact, Digikey probably buys from the same supplier. Why the price diff then? Probably because you can easily return the part if it doesn't meet your spec or other needs (good luck with doing that via China/Ebay), and also because they are relying on your FUD response to think they are more "reputable" because of that. Ultimately, though, you should just buy a certain percentage more number of parts for China, call it "overage due to failed parts", take any losses out on your taxes (if there are any) as part of doing the business (what do you think Digikey does with their returns?), and get over your FUD. Nowadays, you'll find few electronic components (or much of anything else it feels like, sometimes) manufactured here in the USA, let alone the west; all of that manufacturing has moved to Asia and China. It is unlikely to return to the west in the near future.
Guess you purchase you medicine cheap from "on line" pharmacys instead of the local drug store.
Why would I go online when the border to Mexico is just a couple hundred miles south?
Why would I go online when the border to Mexico is just a couple hundred miles south?
Probably not a problem with "laser pointer" drugs that are not "mission critical" and are too inexpensive to counterfit. Of course you can also go get the deal on the expensive injectable anti cancer drugs in Mexico too.
kf2qd:
Because when you buy from a reputable source you are getting exactly what you orderred. That is why they are a reputable source. When you buy from Sam Wong in china you have no idea what you are getting.
Yes, that much is obvious. But that only answers the question of why they're more expensive, not why they're 10-20x more expensive. LEDs from Chinese ebay suppliers are not significantly less expensive than LEDs from reputable suppliers. Also, it does not explain how inexpensive laser pointers exist. With so many inexpensive laser pointers out there made by reputable companies they must have a reputable supplier who sells the diodes cheaply. Really cheaply. Cause they're not putting a $10 diode in a $10 laser pointer, and they're sure as hell not putting a $100 diode in a $10 laser pointer.
In the US you are also paying for some lawyer because the manufacturer and the distributor have to protect themselves from morons who hurt them selves using this stuff when they don't know what they are doing.
