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

[Marco Polo]

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

If it doesn't have reverse polarity protection, that's a design flaw, IMHO. Reversed batteries is an easy mistake to make and surviving it should be a basic requirement of any electronic circuit. Even if it makes the driver more expensive, it has to be cheaper than a new diode.

 

[Blarg King]

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

Its especially tricky to keep track when I've got 4 similar lasers where some are tailcap positive and some are tailcap negative.

The only one that has any indication of which way the batteries should go is my Skylasers 532.

 

[NightExplorer96]

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

Its especially tricky to keep track when I've got 4 similar lasers where some are tailcap positive and some are tailcap negative.

The only one that has any indication of which way the batteries should go is my Skylasers 532.

Maybe take some post-it notes and write down which lasers are tailcap + & which are taicap -. It wouldn't hurt to try

-Alex

 

[RYDorDIE278]

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

If it is very important to anyone they should look for reverse polarity protection before purchasing, not after one dies,
I can understand it sucks for a laser to die Blarg, But if you never had a laser casaulty and always had correct polarity im guessing you would be 100% happy with all your lasers and no problems with the types of drivers and features etc,

 

[tsteele93]

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

Most of the lasers in my sig have died over the past two years. Many of them due to rev polarity problems.

I suggest as soon as you get a laser, mark one side clearly. You THINK you will remember but a year later you have no idea. Even worse, many of the lasers are built in a way that they do not use the originally correct terminals that were used by the flashlight they were built inside of...

Even if it is a red sharpie, somehow you need to mark polarity.

I agree with you that for as expensive as these things are, they should come marked. But you gotta remember many of these lasers are built by (smart) kids and they haven't learned to document yet. Much like a smart coder who hasn't learned to doc yet.

In the end it is up to you to save your stuff. Believe me, I have a grand in lasers that are parts.

 

[Shadowsix]

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

Sorry for your loss. For the prebuilts I have, I've put battery polarity labels on them (My rayfoss came with a label already on it, gave me the idea for subsequent ones I bought).


I'm still rather new here so I waited to see if someone else more experienced would chime in but for those who do their own builds you can easily make reverse polarity protection yourself.

Depends on how much either of the voltage you want to (or can) give up in trade depending on your supply batteries & the drive's minimum voltage to run.

Using a simple cheap silicon diode it can be done if you can stand 0.7V voltage drop across it (loss). Just putting it polarity correct series in either positive or negative supply wire to the drive.

A little more expensive Shottkey diode will do it for only 0.3V loss.

And a properly chosen few dollar MOSFET will do it for only 3mV loss!


Complete explanation with diagrams (very simple schematics, even for the MOSFET) is here: Reverse polarity protection for your circuit, without the diode voltage drop.

 

[Thejoker301]

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

Hi ,

I am sorry to hear this. Happen to me a lot of times.

But , I actually had some cases in which the diode survived that.

In anyway , I offer a repairing service for no profit at all to all my customers.

I sent you a PM. The cost is pretty low.

:beer:

 

[rhd]

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

Which begs the question,
WHY THE F*** DOESN'T IT 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.

Am I the only one that never, even once, inserted battery the wrong way in?

Nope. I'm in that camp with you. As you can probably tell from my post above, I am absolutely baffled that reverse protection is even "a thing". I don't get it.... I just don't understand how anyone gets this wrong. There are only two options to keep track of.

I'm sorry for the OP's loss and all, but when you start swearing (albeit censored) at the manufacturer of a product for not incorporating "protection measures" that they wouldn't need to were it not for your own carelessness, I lose a lot of sympathy.

 

[Thejoker301]

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

I talked to him. I will probably fix it for him

He had it for 8 months +-. I offered him a fix for no profit at all. Just bare cost of the materials.

Lets not take this thread the wrong way.

:beer:

 

[RYDorDIE278]

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

I talked to him. I will probably fix it for him

He had it for 8 months +-. I offered him a fix for no profit at all. Just bare cost of the materials.

Lets not take this thread the wrong way.

:beer:

I told him a few posts back to contact you with the right attitude and that you will do your best to keep him happy! even though it was a simple mistake which he must accept and learn from, your a good man alright Eitan!
EDIT: tryed to +Rep you but i cant ATM

 

[Marco Polo]

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....

A blocking diode is all it would take.

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.

Invalid hyperbole.

Nope. I'm in that camp with you. As you can probably tell from my post above, I am absolutely baffled that reverse protection is even "a thing". I don't get it.... I just don't understand how anyone gets this wrong. There are only two options to keep track of.

You've never inserted the batteries the wrong way in anything, ever? HAIL JESUS.

I'm sorry for the OP's loss and all, but when you start swearing (albeit censored) at the manufacturer of a product for not incorporating "protection measures" that they wouldn't need to were it not for your own carelessness, I lose a lot of sympathy.

Customers are careless. It's a fact.

Also, people make mistakes, and when you have dozens of lasers, with differing battery configurations, things get mixed up. Any laser hobbyist knows this, and any hobbyist who sells lasers or drivers should just keep it in mind, expect it, and plan accordingly. Plan ahead to head off Murphy's Law.

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.

 

[rhd]

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

A blocking diode is all it would take.

Yes, I know what's involved I created the "Magic Flipper" which not only protects against reverse polarity, but actually corrects it. I still think polarity protections are silly.

You've never inserted the batteries the wrong way in anything, ever?

Correct. Why would I do that? It can damage the laser you know

Also, people make mistakes, and when you have dozens of lasers, with differing battery configurations, things get mixed up. Any laser hobbyist knows this, and any hobbyist who sells lasers or drivers should just keep it in mind, expect it, and plan accordingly. Plan ahead to head off Murphy's Law.

Well, I guess I don't have a lot of lasers? Or I'm not a hobbyist? Because I don't get this stuff mixed up. If there's ever a laser that is for some reason not the polarity I'd expect, I just make a note inside the tailcap with sharpie. I think that's what many other members do too.

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.

Nope. Lots of drivers just don't have reverse polarity protection. They're not necessarily cheaper drivers.

PS, my analogies were awesome. They were absurd fictional protections that no rational competent person would need

Strong praise is owed to the seller IMO for stepping up and offering to repair this laser even after the customer swore at him, and 8 months after the fact. That shows a real willingness to go above and beyond.

 

[ARG]

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

Nope. Lots of drivers just don't have reverse polarity protection. They're not necessarily cheaper drivers.

Out of all of these drivers, only 3 advertise having reverse polarity protection.

GrooveDrive V2
Mohgasm Linear Driver
IRON4D
Mosquito
GhostDrive2
Jib Driver
RKCSTR V3
X-Drive V6
BlitzBuck V2
BlitzBuck V3.1
BlitzBuck V4
BenBoost
Micro BoostDrive V1
X-Boost V7
AtMa Boost Driver
Micro FlexDrive V5
Micro FlexDrive V3
Elasti-drive
FMT V2


It is the norm for drivers to not have reverse polarity protection - I think it's an unreasonable to expect that any laser has it built in.

 

[Marco Polo]

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.

ETA: And yes, Crazyspaz, it IS the fault of whoever designed the driver. That's the nature of design flaws. Poor design is not the end user's fault

 

[Rifter]

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

A blocking diode is all it would take.

You do realize a diode would also eat .7v or .3V of your voltage which you could probably spare with full batteries but not so much as they drain.

Granted you could also incorporate a MOSFET for reverse polarity protection but depending on the driver there may not be room on the PCB for this, might also not be room for even a diode depending on the driver.

 

[ARG]

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

You do realize a diode would also eat .7v or .3V of your voltage which you could probably spare with full batteries but not so much as they drain.

A parallel diode with a series fuse would also work well, bit of work to replace the fuse when it blows though.