Compilation Of Information (First Major Build)

Re: WIP Complete Laser Creation Tutorial

The 400x's will get incredibly hot almost instantaneously when testing at 1A. You either have to be ready to set that pot super fast or you need some bigger diodes.

Re: WIP Complete Laser Creation Tutorial

Pontiacg5 said:

The 400x's will get incredibly hot almost instantaneously when testing at 1A. You either have to be ready to set that pot super fast or you need some bigger diodes.

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Yeah I got it. If you look on that page, it shows the maximum current of the diodes as well as the reverse voltage.

Re: WIP Complete Laser Creation Tutorial

If you do a search for "1N4001 datasheet" and read any of the PDF's that come up you get all the info like max current. Looks like 1.0A rating on all in the 1N400X series.

Re: WIP Complete Laser Creation Tutorial

Please read the above posts, before posting, Thank you.

Re: WIP Complete Laser Creation Tutorial

I know you found it already - just wanted to suggest a more convenient method of finding the specs on a part. This way you only do one search and you're done, guaranteed correct info

Re: WIP Complete Laser Creation Tutorial

lasersbee said:

2 in parallel two times... and those to sets in
series to get you 1.0 Ohms @ 1 Watt...

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Hi, sorry for the correction, but this make it 1 ohm 2W ..... power is based on dissipation, so, regardless the fact you use them in serie or parallel, the powers are always summed (or multiplied, where they are equals, like in this case, so 4 x 0,5W = 2W)

Also, if someone really need a bigger one (more than the 2W), can use 9 of them for make an 1 ohm 4,5W resistor, placing them in parallel in groups of 3, then the 3 groups of 3 in serie .....

Just as suggestion



@toaster (about the resistors): Yes, being all equals, you can place them in serie 2 by 2, then the 2 series in parallel, or place them in parallel 2 by 2, then the 2 parallels in serie (same for the 3 x 3 example) ..... the result don't change, you still have 1 ohm at the end (basic ohm law).

Anyway ..... the other important thing to take in consideration, building a test load, is the diode dissipation power (also the diodes dissipate power as heat, after all), not just their currents ..... 1N400x serie is rated for 1A MAXIMUM current, and also have a typical power dissipation of 1W ..... but, as all small axial diodes, have also a small heat dissipation surface ..... they can survive to 1A, but in some cases they can become so hot to melt the solder alloy on their own terminals ..... if you are planning to make a test load for test 1A or more drivers, i suggest you to use at least 3A diodes, better if 5A ones, and to place some heatsink on them, too ..... i made one for a burn-in test using these diodes and a big heatsink, and after some hours at 1,2A, it was too hot for keep it in hand

Re: WIP Complete Laser Creation Tutorial

So the 2x2 will make a 2 watt 1 ohm resistor? Which will be adequate, correct? Also The 1N540x diodes are adequate as well? Or should I go for bigger there? I can't recall what the bigger ones were, I will have to look it up real quick...

Wel on this sheet Here, they are called S5AC's.. Is that Right? I am kind of new to electronics so I want to make sure I am right here

(The 5 amp diodes)

Re: WIP Complete Laser Creation Tutorial

S5A serie is in SMD package (surface mount) 5A diodes ..... 1n540x serie, if i recall correctly, is a 3A diode serie .....

I think you can use any from the BY500x serie, or from the FGP50x serie, or a GI821/4, or MR822, if you need 5A silicon diodes ..... they are almost all standard products, so must be easy to find them from one of your distributors, or maybe online (i think, if you are in the USA, that the bigger distributor is digikey or some other similar sellers) ..... or from ebay, maybe .....

Re: WIP Complete Laser Creation Tutorial

I like where this thread is going! :wave:

Re: WIP Complete Laser Creation Tutorial

Thanks for posting one of my picture. Always wanted to do a complete Tutorial.:beer:

Nice thinking.

Re: WIP Complete Laser Creation Tutorial

I yeah, I have been collecting pictures. I took no credit, BTW It was an amazing picture, no to mention I LOVE your counters. I'll add you to the credits, I didn't want to clutter the main point with a million "Thanks to ..." Throughout.

Re: WIP Complete Laser Creation Tutorial

Toaster said:

I yeah, I have been collecting pictures. I took no credit, BTW It was an amazing picture, no to mention I LOVE your counters. I'll add you to the credits, I didn't want to clutter the main point with a million "Thanks to ..." Throughout.

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Thanks, No need to i was just saying thanks for posting it and cant wait to see your tutorial.

Re: WIP Complete Laser Creation Tutorial

Hey guys I picked up some 3 amp diodes today and I realized after I purchased that they say EPOXY on the top, now will these not work the same I am not an electrician.

Re: WIP Complete Laser Creation Tutorial

They will likely be just fine. If you have a multimeter with a diode tester* in you can simply check their voltage drop. As far as I know there are only two types of diodes, silicium and germanium, with 0,2V and 0,55V drop. You just add them up to match your laser diode. Their purpose is simply to provide a voltage drop with a current characteristic similar to a laser diode. That is, a drop that does not increase much with current. *The diode symbol on the meter, when measuring on a diode it will show volts, usually 0,55V.

Re: WIP Complete Laser Creation Tutorial

I thought The drop per diode was .7 volts?

Re: WIP Complete Laser Creation Tutorial

Depends on the model of the diode. There is a whole range of drop-out voltages among diodes, as low as 0.3V and up to 100V (maybe even 100s). As the diode gets hot from higher current the drop-out voltage slowly goes up.