God i hate drivers. Can i do this instead?

[Lascannon]

OOK... Well this is awkward. I just joined a forum where everyone here is older, more experienced (well, ok, maybe not that last) and beter at electronics than me. Hi. Im Liam. I am trying my first build. I have a 20x dvd burner diode (two actualy) and im trying to make a laser pointer... I tend to look down on those who say "oh, i made this, caugh caugh, by which i mean i ordered all the parts online and put them together in ten minutes" so instead of doing the smart thing and ordering a driver online like everyone else, Im trying to make one. After two failled atempts, i am questioning weather (wether? how do i spell this anyway? and im not sure about awkword either) this is realy as complicated as it seems.

I have viewed the tutorials here, and they mostly say that you need a capacitor to capture voltage spikes, and then you need a lower current (if you using two AA bateries, that is) so i need around 300-400 mA to run this thing, so i crunched the numbers and a 10 ohm resistor hooked (hoocked? hocked?) to three volts should be about right, maybe a little under. I have no reason to ad (add? ade?) a potentiometer(yes, ok, i promise il look up the spelling soon) so why wont this circut even run a small engine? I set up two AA bateries, a 50v capacitor, then a 10 ohm resistor and a button(buton?) to an electric engine, and its not even turning, so i was wondering what the problem is... Did i just wire it wrong? Did i make a mistake with the math? Is the capacitor somehow eating all my volts? Im kind of fuzzy on my electronics (and yes, i have a few books, im working on it, just takes a little while on top of the comunity college and highschool classes and all that.) so if anyone can help me that would be fantastic.

Short verson for all the buisy types:

Im trying to build a driver for a 20x dvd burner diode of unknown model
I have little or no electrical experience, but im handy with an iron
I want something simple, easy, and preferably (how do you spell that again?) fast.

Thank you all,
Liam.

PS: please, no links to the newbys thread, Ill read it write after im finished here.

 

[bluuray]

3v? use lithiums , 3v isnt enough

 

[Cyparagon]

I tend to look down on those who say "oh, i made this, caugh caugh, by which i mean i ordered all the parts online and put them together in ten minutes"

...Im trying to make [a driver].

*cough cough* and by which you mean you ordered all the parts online and put them together in ten minutes?

 

[Lascannon]

Cyparagon, Im afraid i do not understand your post.

bluuray, in my opinion 3v should be fine, since according to a number of diagrams found on this very forum under the tutorials secton, 2.5-3 v is perfectly functional.

I am rather disapointed, Cyparagon, that you could not include a simple yes or no in your post. After all, you are a "3b laser" arent you?

Will no on answer my rather simple question? I am asking for a yes or no, if yes thank you, if no please include a "why" if it isnt to much trouble.

Thank you,
Liam.

 

[Toke]

The most likely explanation is that you have connected the capacitor in series with the resistor.
Capacitors are well known to block DC current which is what comes out of batteries.

Another problem you will run into is that the 10 Ohm and 3V leading to 0.3A is kind of invalidated if there is anything else in the circuit to eat voltage.

I recommend getting your hands on a simple voltmeter to check voltage drop at different points in your circuit, and a 1 Ohm resistor to insert and measure the current with.
(100mA going through a 1 Ohm resistor will produce a 100mV voltage drop across it)

 

[anselm]

What he says about the cap in series.
Also, read this:
Laser driver - It can be done
Enlightenment will ensue.

 

[inuboi8]

lol welcome to the forum, i wish i was good at making my own drivers too, then i could experiment with new host ideas sadly its a pain in the butt to do

 

[Lascannon]

anselm. I have many helpfull familly members. Normaly, I say thank you by making them a cup of coffee, buying them a coke, helping them with a project, basicaly i like to show apreciation(apretiation? apretiacion?) to those who help me. Sadly, i am left with only words.

Thank you for giving me a good, simple, answer. I have been enlightened.

Toke. Thanks. That was so simple i neerly died laughing at myself.


Thank you all. I will now vanish into my basement and (I hope) reapear(spell check, please?) with a burning laser.

Thanks again,
Liam.

PS: This forum is fantastic.

 

[Lascannon]

Oh no! A double post! So i had an idea. I need to keep the voltage output from going over 3v, right? Otherwise im going to burn out my diode. So what if I put on a Zner chip and a 10ohm resistor? The Zner chip cuts power whenever it goes above three volts, so any surges and it will just shut itself off untill its done, and as for the current, I just need to get it to 300-400 mA to be safe, so a 10 ohm resistor will lower resistence to safe levels.

Would this work?

Thanks,
Liam.

 

[Cyparagon]

1. To avoid double posts, click the "edit" button at the bottom right corner of your most recent post.

2. Firefox (use the Google) will help you out with your spelling.

3. Don't mind the user titles or post count - they don't mean much.

4. I was pointing out that you look down on others for building lasers out of components, yet you're doing the same with your driver. (if you can call it that)

5. Batteries don't give "surges." An alkaline cell will stay under 1.6V pretty much no matter what you do.

6. I think by "Zner chip" you mean "zener diode."

7. It depends on the zener. Only a 3V zener will do as you say (minus the "shutting off"), and only in parallel reverse bias. It also depends on the nature of the surge.

8. A 10 ohm resistor doesn't lower resistance, it raises it. It lowers current.

9. Simply putting a resistor in series with a diode is called direct driving. It works (if done properly), but you'll never see full power; the current, and therefore output power, falls with battery drainage.

10. Did you learn anything in those newb threads you read?

 

[Benm]

Like it or not, building a proper driver is part of the process. Laser diodes are current driven devices, batteries are voltage sources, so there is no way to avoid doing some proper electronics in between.

You could just ignore all advise and hook it up direct drive or with a series resistor, but the result would be a kipkay fail - the sort that gets many people on this forum i suppose.

 

[LarryDFW]

You do not have to have a driver for a Red LD and 3 VDC battery.

I have a couple of Red lasers that are direct drive from my 4.2 VDC cells.

The resistor needs to be smaller for 3 VDC.

I would guess around 1 to 1/2 ohm when you add the IR of the battery.

Check the current with a meter.

LarryDFW

 

[Lascannon]

Thank you all for your help and input.

Cypragon, thank you for taking the time to explain why as well as what. Sory about the slight confusion with resistance, current. Firefox is downloading as we speek.

Benm, I think you are probably right here. If there were a simpler way of making a driver that didnt greatly reduce your diode life, Im sure it would have been done already.

As for Larrys suggestion that maybe i shouldnt use a driver at all, thank you for the reminder that this is allways and option. However, I have destroyed many, many electrical projects over the last two years (i only recently started the electronics thing as a hobby) and i hope you wont be offended when I go with the suggestion of the many people telling me i do need a driver, rather then pulling a kipkay.

Thank you all.

I think i will just try to build the driver as shown in the enlightening tutorial. i say i wanted to learn electronics, so why am i hiding from a little soldering?

I dont want to annoy anyone, but if i put up a few photos when im done, could you guys critique it for me? No one else in my familly (grandfather aside) has any electrical experience, and certainly no one has tried to make a laser, so i dont realy have anyone else to ask...

Thank you all,
Liam.

 

[Bionic-Badger]

Just curious, is English your first language? You have a lot of spelling questions and stuff, but other than that, there aren't any errors and the writing sounds natural.

 

[Lascannon]

It is my first language, but I just came back from a month in japan, and I speek five languages fluently, so sometimes i get a little confused. Im used to thinking in japanese at the moment, and they put all there verbs at the end or the sentence, and of course they use kangi alphabets, so Im still adjusting back to english. Im trying to improve my spelling any way i can, since I just got accepted to MIT and i would rather not be completely reliant on spell check while im there... English has worse spelling than any other language i know other than maybe french.

Thanks,
Liam.

 

[Toke]

Regarding simple mistakes to avoid, there is at least one example where someone made a testload on testprint with print lanes and then forgot to cut the lanes between solder point.