why case pos?

Why are 532nm always case positive? So does that mean the current is running through the host to the driver? What grounds it then?

nwfreefly said:

Why are 532nm always case positive? So does that mean the current is running through the host to the driver? What grounds it then?

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Because the IR pump diode is always case positive, so the host must be wired host positive, then the positive is connected directly to the diode through the host.

As far as I know only IR are case positive and therefore the DPSS lasers that have to use them.

Most of the diodes we use are case neutral.

Some are case negative, I think only some red ones.

If it's case neutral you can wire it either way, but if it's case positive or case negative then you have to wire it that way or else it must be insulated from the host, otherwise it's going to go up in smoke when you turn it on.

Alan

Did you really need to start two separate threads, one asking what case positive meant, and one asking what continuous ground was?

The answer is easily searchable, and it's basically the same question.

rhd said:

Did you really need to start two separate threads, one asking what case positive meant, and one asking what continuous ground was?

The answer is easily searchable, and it's basically the same question.

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You neg rep me for asking legit gdamn questions? Maybe this is all basic common sense to you but its not to everyone else.
I did do a search and the threads that came up were discussing different aspects of using continuous ground drivers and how to hook them up with the presupposed assumption of knowledge of what they are. Don't try to make me out like I'm some lazy member asking to be spoon fed. I do hours of reading of past threads and wiki pages close to every night trying to learn this stuff I don't need to get shit for it if i am having a problem finding answers so post a question that you may find so easy.

I didnt ask what case positive means if you took a second to read my questions they were for explanations of why 532 are always this way and how the current gets to the driver. maybe try to put yourself in someones shoes that doesnt have any background or people to ask in person.

Go ahead take all the rep you want. Its more the point. Im trying hard to learn so don't imply I am being lazy.

I think it's just more that these are, conceptually, basic electronics questions. I'll give you the benefit of the doubt that maybe you haven't found a good resource to read up on electrical stuff.

For this particular set of questions, the concept is that current will flow through a conductive path, and all directly conducting areas of the circuit will share the same voltage potential. So if something is case positive, everything that touches that part of the circuit will be at +V. If something has a continuous ground all points that conduct to that ground reference point will be at ground.

Why are green modules case-positive? That's just how they're made, probably for reasons Pi R Squared mentioned. Most of those green laser modules are made for pointers too; forcing manufacturers to use a case-positive part won't really affect sales.

On the other hand, diodes such as 445nm diodes are manufactured with pins that are not attached to the case to give users greater flexibility in integration. If the diode were case positive or negative, the heatsink those diodes were embedded in would be at that reference, which would preclude something like powering eat diode with completely separate voltage references.

Finally, though you can probably get by building lasers without too much knowledge, you should probably brush up on some basic electronics on some sites on the web (sorry, I don't know any off the top of my head). Then you'll be less liable to burn out expensive parts. A good test of knowledge is fully understanding why the LM317-based driver works, and what the effects of extra voltage or other stuff has on the circuit. The same thing with op-amps, and transistor networks, etc. It's just good knowledge to have.

Bionic-Badger said:

I think it's just more that these are, conceptually, basic electronics questions. I'll give you the benefit of the doubt that maybe you haven't found a good resource to read up on electrical stuff.

Finally, though you can probably get by building lasers without too much knowledge, you should probably brush up on some basic electronics on some sites on the web (sorry, I don't know any off the top of my head). Then you'll be less liable to burn out expensive parts. A good test of knowledge is fully understanding why the LM317-based driver works, and what the effects of extra voltage or other stuff has on the circuit. The same thing with op-amps, and transistor networks, etc. It's just good knowledge to have.

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I fully agree and acknowledge this is my main problem understanding a lot of what I read. RHD is absolutely wrong in thinking I didn't do a search and some reading. I did, the problems arise when i don't understand much of what is in the threads that I am reading. But you're right and I will try to find a source of the basics so I can understand better.

What some don't understand is that sometimes people ask repeat questions because they need things explained differently or for clarification.
I don't appreciate RHD rude comment left with his neg rep because coincidentally earlier tonight I was just expressing my frustrations to my wife. I told her I am frustrated because I can't remember any other thing where I put this much time and effort into a new subject yet feel Like I am getting no where. But you really hit the nail on the head though. I need to start at the basics.
Thanks BB ans thank you Alan. you're help is much appreciated.

I neg repped you because if you had bothered to put "case positive" into the search bar at the bottom of this screen, you'd find numerous pre-existing threads and posts on this exact subject. You're supposed to search before re-asking the same question that has been addressed numerous times.

EDIT: look how many hits you get when searching this topic - screens full. This thread even has diagrams:
http://laserpointerforums.com/f50/how-wire-case-positive-diode-87011.html

Well, you got your answer at the cost of a neg, I suppose that isn't a bad trade, I got negged once for asking a question about 808nm optics for a FAP laser the negger thought I should have been able to find through a forum search (I did search, a long time at that) and still don't have my answer! For myself, I'd prefer only being able to give positives, if you don't have anything good to say then just don't say anything at all

I've noticed some of the most laser technology brilliant individuals with the highest reps in the group are also the quickest to neg here, interesting interrelationship. I won't neg anyone anymore, not for anything... notice I'm not the brightest here nor have a high rep, hummm.... less ego?

Alaskan said:

Well, you got your answer at the cost of a neg, I suppose that isn't a bad trade, I got negged once for asking a question about 808nm optics for a FAP laser the negger thought I should have been able to find through a forum search (I did search, a long time at that) and still don't have my answer! For myself, I'd prefer only being able to give positives, if you don't have anything good to say then just don't say anything at all

I've noticed some of the most laser technology brilliant individuals with the highest reps in the group are also the quickest to neg here, interesting interrelationship. I won't neg anyone anymore, not for anything... notice I'm not the brightest here nor have a high rep, hummm.... less ego?

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This is a recurring theme with this user. In about 2 months of being a member here, "nwfreefly" has created 40 new threads. Most of them to ask questions that are answered NUMEROUS TIMES in NUMEROUS THREADS already. Among them are questions like:

What is continuous ground?
Does the G2 lens create greater power than 3 element?
When you use 2 batteries does the combined voltage double?

Most users won't give negative rep just because a user is "new" to the forum. However, when a user repeatedly starts brand new threads to ask questions that would be answered if they'd just take the time to use the search function, then it's warranted.

rhd said:

This is a recurring theme with this user. In about 2 months of being a member here, "nwfreefly" has created 40 new threads. Most of them to ask questions that are answered NUMEROUS TIMES in NUMEROUS THREADS already. Among them are questions like:

What is continuous ground?
Does the G2 lens create greater power than 3 element?
When you use 2 batteries does the combined voltage double?

Click to expand...

What a wonderfully inaccurate portrait you are attempting to paint here.
Thats as pc as I can put it.

Because a thread may contain an easily found question among many other inquires is not the same as a thread CREATED TO ASK AN EASILY FOUND QUESTION.

I'm guessing the below link is the supposed thread in which I asked the very basic question of which lens has more power. This is a flat out lie.
http://laserpointerforums.com/f49/some-clarification-questions-regarding-lens-choices-92209.html
Funny I don't see that in there. What I do see is a request for opinions about the gain in power for g3 lens being worth the suffering divergence. No where in there did I ever ask what lens is more powerful. Not only did I not ask this In fact I stated the g3 is 30% more powerful right there in the first paragraph, so thanks for lying about what I asked.

I never made a thread asking about volts. I made a thread about a broken laser and that was one of MULTIPLE things I brought up as a possible reason. Stop cherry picking to prove your weak point.

If you have gone through the effort of looking up the subject beforehand, you should establish that before posing your new question -- especially if the question seems pretty basic. "I read up on X here, but didn't understand this Y it described." That way you're not asking general questions, but rather specialized questions, and demonstrating that you did go through the effort. It's like asking technical support for help without first reading the manual.

There is also a problem with questions that are either too general or not really the "right" question because you don't understand the underlying concepts to ask such questions. I think your case-positive question falls into this category, especially since you followed up with questions about how current flows and where ground is.

If you're asking the wrong questions you're going to receive the wrong responses. In this case, you asked about "case-positive" lasers, when that really has little to do with your understanding of circuits -- which is what you really need to know. Those lasers are case positive because that's how they're made. There's nothing more to it really, and the explanations given above for "why" are basically just trivia, which doesn't really help you.

You may also receive responses like RHD's where you're expected to find the answer to wiring issues in the search box. The answers in the search box will tell you how to wire things up, but if you don't even know what wiring up things really means, it's not going to help you.

So when you don't know the answer to something, first consider whether you actually need more background knowledge to ask a more precise question. Brushing up on some basic electronics would help a bit. If you are still confused about the concepts, ask about those, but don't just jump to more advanced topics without understanding the basics. Otherwise, we're going to assume you already know them, and if you don't, it'll seem like you aren't putting in the effort to do the research yourself.

Here is my "being a full time mechanic" aspect!
98% of cars out there are "case neg" there are a million components on a car that need pos and neg! If the whole "case"/ frame of the car is neg than you have less wiring and whatnot to deal with. Most flashlights are case neg as well. It just depends on the circuit. In this case the IR diode needs to be case pos for the circuit to be complete.
Some British cars are "case pos" which makes it next to impossible to wire a stereo into
Hope my input helped

That's the problem with forums. Important information or specific information you are looking for is spread out in threads. The answer could be on page 2 or reply 151 or something so I can understand the frustration and reluctance to search. On the other hand you have people who have been here a long time and have seen thread after thread of the same kind of newbish questions so I can see the frustration with that. It's no doubt that some heads are going to butt

VisibleGreen said:

That's the problem with forums. Important information or specific information you are looking for is spread out in threads. The answer could be on page 2 or reply 151 or something so I can understand the frustration and reluctance to search. On the other hand you have people who have been here a long time and have seen thread after thread of the same kind of newbish questions so I can see the frustration with that. It's no doubt that some heads are going to butt

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Well said and I can understand peoples disconnect that the fact that not all answers or explanations are as readily available as their years of expertise feel they are.
But you know what I think is a shame? The big ole roosters that like to strut around with their chests puffed out carrying their almighty neg rep sticks trying to intimidate new members with a bunch of numbers next to their on line identity's. RHD trying to reduce my contributions and inquires down to a waste of everyones time over a couple poorly asked questions.

You know what I wish RHD could know. That I have spent the past week searching and reading to try to learn what is probably a laughable simple task to most of you, how to set a drivers current. Yes, I know the theory behind it and what is happening but when I approach the multi meter and a driver I have no confidence in wtf I'm doing. A multimeter for me may as well be the Antikythera mechanism. So yes I'm a bit frustrated. And i am a bit tired.

When I filter through the pages and pages of content to find parts of an explanation I'm looking for but often only grasp about 30% of the content. It feels like I'm pulling tiles out of a bag that have words on them which individually I understand, but when put all together make little sense. So sometimes I just need to have something explained very basically. I will head BB good advice and sense and I thank him for taking the time to help me rather than ridicule me. I will learn what it is I know and what I don't, and do more reading of basics of electronics and not just lasers so I can ask better questions.

You know what people like RHD dont get? That what is as basic as "see spot run" to him, is quite challenging to a person that can't read. So maybe this hobby isn't for me but I've never failed at anything that I have put this much care into and I don't plan on it now.

I'm gonna build a laser. I'm gonna build it from the ground up as much as is realistically possible with as much understanding as possible. I'm gonna point that beam into the night sky and when someone walks by and ask me where I got it I'm going to be able to say, "I made it". And you can neg rep me as often as the forum allows but I will reach my end goal. I will improve my asking of questions in PM's rather than make threads but ...I will not tip toe around the big ole rooster.
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For me at least, I sometimes have to keep repeating "I don't know what it is I don't know" and act accordingly.

For example, for my 445 3 watt, the first diode was round, and the second one that replaced it was square...and the case polarity was reversed. Same wavelength, reversed polarity...a bit of a learning curve.

I'm a bit dyslexic to start with, and, well, I have in the past fried a few things because I accidentally put cells in the wrong way, or forgot which light I was loading, etc.

I found I don't need to start many threads though, as the info I would have asked tends to either show up in a search, or, the search leads me though a rabbit hole and I end up reading about other stuff anyway.

There has been a bit of discussion about just how useless the tutorial stickies and other such stuff is on this forum. I recall seeing if I could find some basic information to get started as if I were a new user, and the information is usually buried a few pages into some posts, or on different pages, etc. Plus the forum search sucks, and even the Google searches are often unreliable.

Mostly I'd concentrate on just having a decent background in electronics. Most of the lasers built here are more about wiring and soldering rather than constructing something complicated. If you can understand how voltage and current works, how to build stuff like dummy loads and simple drivers, and can do a decent job of soldering, you're about 90% of the way.