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Apparently most lasers don't have polarity protection *SOLVED*

crazyspaz

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

This is starting to remind me of that guy not too long ago that came in cussing and raging about o-like being "shit" because he stuck his battery in and fried the laser. Then he got a free replacement and still complained...
 

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

I guess because they assume we're all competent human beings, and can get something simple like the direction you stick one cylinder inside another cylinder correct....

The gas tank on my car doesn't have protection from the accidental insertion of window washing fluid, and the muffler doesn't have protection to guard against an accidental insertion of the gas-pump-nozzle while filling up. My shoes don't have wrong-foot protection. My ears don't have protection measures to guard against the accidental insertion of food.
Can you take your condescending tone and shove it? None of the things you list above are similar to reversing the polarity of batteries in a laser.

Sorry that I have a half dozen other lasers, and I don't etch their battery orientations into my skin to remember them. Its not that simple when there isn't a single marking on the laser to indicate which way they go.
 
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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

This is starting to remind me of that guy not too long ago that came in cussing and raging about o-like being "shit" because he stuck his battery in and fried the laser. Then he got a free replacement and still complained...
I have a low tolerance for damaged caused by a known and easily preventable situation.
 

Hap

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

^Blarg

It's a mistake, mistake happen & starting an argument on LPF with others while they are right OR wrong isn't going to solve anything. Best thing to do is talk to the Joker(who has agreed to fix the device for cheap), and find a system to prevent any future mistakes(which I suggested post-it's & others have contributed with their ideas).

-Alex
 
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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

I have talked to him, and I'm figuring it out.
But I don't appreciate anyone implying that I'm incompetent over a easy mistake to make. Or implying that they are in any way superior just because they've never done it.
 
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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

This is starting to remind me of that guy not too long ago that came in cussing and raging about o-like being "shit" because he stuck his battery in and fried the laser. Then he got a free replacement and still complained...
If it didn't have reverse polarity protection, it was indeed flawed.

I should point out I haven't lost any lasers due to reversing the batteries, and I've reversed the batteries many times. Apparently this led me to assume that, like the vast majority of electronics, backwards batteries would simply cause the device to not operate.

I'm also surprised that reversed batteries are even an issue. Not including reverse protection seems like such a silly corner to cut.
 
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ARG

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

I'm also surprised that reversed batteries are even an issue. Not including reverse protection seems like such a silly corner to cut.
From the perspective of a driver designer. These are round drivers limited by the size of the pill, IIRC it is the same pill size as the 501B.




Where do I put the MOSFET for reverse polarity protection in?

Should a single diode be included resulting in a large power loss and greatly lower efficiency? It's not like this is a consumer device with low current draw, these lasers draw a lot of current which means a lot of power is being lost in the diode.

A blocking diode is all it would take.
As above, this would only work for low current lasers. What do we do for high current lasers?

That's my take on it; lack of reverse polarity protection should never be seen as anything but a glaring and unforgivable COST CUTTING flaw. No if's, and's, or but's.
It's not as simple as you think. There are plenty of limitations and reasons for not having reverse polarity protection. If it was so easy everyone would do it.
 
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rhd

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

Reverse polarity protection is easy, and cheap.

That doesn't mean it should be incorporated into every driver.

There's an efficiency loss that I don't want on a driver in any of my lasers, particularly given that there's no corresponding benefit for me (since I don't have a problem with rabidly inserting things backwards). I'll take efficiency over unnecessary features.

And heck, for those who DO have such a problem, if you think is so important to protect yourself from yourself, add the protection. I did, after all, make the coolest polarity protection out there completely open source / free. It costs $1.30 and can be added to any build regardless of driver. I don't use it, but maybe you should.
http://laserpointerforums.com/f67/o...ity-correction-not-just-protection-87367.html
 
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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

If you've been at it for 6 months+ and this is the first
diode you've killed, you're doing much better than
me. We all kill diodes from time to time, even the
best of us (of which I am not). It's all just a part of
the game. Yeah, it makes me angry. It makes us
all angry. Then I suck it up, get over it, man up, and
move on.
 

Shakenawake

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

try being me. the only lasers in my sig that have not needed repair of the diode are my lazerer rifle (go figure), 532nm lasermax genesis, my 100mW 520nm, the spartan I just got, and my projector, barely ever used. some of the others have needed new diodes multiple times. most that die on me last less than 6 months
 

Rifter

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

From the perspective of a driver designer. These are round drivers limited by the size of the pill, IIRC it is the same pill size as the 501B.




Where do I put the MOSFET for reverse polarity protection in?

Should a single diode be included resulting in a large power loss and greatly lower efficiency? It's not like this is a consumer device with low current draw, these lasers draw a lot of current which means a lot of power is being lost in the diode.



As above, this would only work for low current lasers. What do we do for high current lasers?



It's not as simple as you think. There are plenty of limitations and reasons for not having reverse polarity protection. If it was so easy everyone would do it.
I get it but it seems to me the OP has his blinders on, its not so easy as people think with a portable driver and that's why most laser drivers do not have it. There is only so much space you have to work with in a small portable host with a small fixed driver size.

OP look at these pics ARG has posted and if its so "easily preventable" in your own words im sure it wont be hard for you to advise us where you can fit in a mosfet(as a simple diode would be way to much voltage and thus efficiency drop). Keep in mind you cant just throw it on there wherever you see enough physical space(I don't think there is enough space anyways) as the trace length and size and location must be taken into account.

As many people have already mentioned its NOT so easy.
 

crazyspaz

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

I have a low tolerance for damaged caused by a known and easily preventable situation.
You are right, it is indeed easy to insert a battery the correct way.

sharpie + "-" or "+" + tailcap=problem solved
 

rhd

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

Maybe I'm just clumsy, I admit it. I think I've reversed every single laser I've owned and not one of them has died from it. Even my Laser 301's seem unaffected by reverse polarity, so when a 20 dollar Chinese laser can handle it just fine, IMHO nobody else has an excuse.

I stand by what I said - lack of reverse polarity protection should be seen as a design flaw, regardless of how many drivers don't have it. Reverse protection is a basic preservation feature and every driver should have it. All of those that that don't are flawed (defective by design, basically) and should be updated.
It's not a design flaw to omit a feature consciously, because its inclusion carries more detriment than its exclusion. Including reverse polarity protection is a judgment call that involves weighing features like size and efficiency against features like protection against clumsiness. Efficiency and size win the weighing of priorities for most of us. If they don't for you, then do what everyone else in a DIY hobby does... build your own stuff.

Can you take your condescending tone and shove it?
Not without protection.... I might shove it up there the wrong way :na:
 

Rifter

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

It's not a design flaw to omit a feature consciously, because its inclusion carries more detriment than its exclusion. Including reverse polarity protection is a judgment call that involves weighing features like size and efficiency against features like protection against clumsiness. Efficiency and size win the weighing of priorities for most of us. If they don't for you, then do what everyone else in a DIY hobby does... build your own stuff.



Not without protection.... I might shove it up there the wrong way :na:
I wish I could rep you more LMAO!!!!
 
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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

If a builder keeps unprotected drivers to themselves, that's one thing, and no problem - the only person at risk of an accident is the builder. As soon as the drivers start getting sold/supplied to others, that is when either a) the devices should be protected by default, or b) the person selling should clearly state that the device lacks reverse polarity protection.

If someone sold me a laser and didn't tell me it lacked reverse polarity protection I would feel that I had been sold a defective product. It's fine if I'm warned in advance, but if not then the seller didn't hold up their end. Details like that need to be mentioned explicitly.

That's a pretty driver board but without the reverse protection I would never use it. Where to add a diode or whatever? You can't, you'd have to redesign the thing from the ground up. That is unfortunate, because I know it sucks to get attached to a design only to realize it's fundamentally broken and has to be scrapped. But that's the light in which I see unprotected drivers. *shrug*

Anyway that is my opinion, I'm not sure what else I have to say about it.
 

Things

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Re: Apparently th Sci-Fi Lasers 501B doesn't have polarity protection

For the amount of power wasted, I'd prefer drivers without.
 




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