"Help!" for: Electronics

[thatdecade]

Courtesy of Cool HTML to BBCode Converter

If I took a battery, such as this
And hooked it up to a voltage regulator such as this
Would I basically have a big power supply with a constant 3.3 volts going to my LEDs? I plan on getting these LEDs

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Thanks for the super explanation ventrue, but I think you forgot to mention mAh = milli Amp hours

Battery is rated 5000mAh and LED draws 20mA.
5000mAh / 20mA=250 hours

Edit: Like ventrue alluded, it is hard to know what the current is just by doing math. The best method is to measure your circuit with a multimeter and determine the exact draw of mA. Then you can get a better estimate.

 

[ventrue]

I think you forgot to mention mAh = milli Amp hours

Nah, I think I mentioned that... ah, somewhere? :-D

But people should know that anyways, shouldn't they? Isn't that like 8th grade stuff?

 

[ShinigamiNG]

I see, the two of you are both very helpful and knowledgeable lol. I'm assuming that if each LED draws an average of 20 mA, and then I have 10 LED's, it would then stack up to about 200 mA. So if I had a battery setup with 1000 mAh, it would last about 5 hours? And that's assuming with those color changing LED's I was only using one color. Turning on multiple colors would increase the draw, and the batteries would drain faster. And, like you said, the current doesn't always stay constant, so I probably wouldn't get the whole 5 hours out of it, maybe 4 or so. With one color.

So, how many mAh is in those NiMH cell AA's? I found these -> http://www.photonlight.com/products...-AA-Batteries-%2d-4%2dPack,-NiMH-2700mAh.html
That claim to have 2700 mAh, is that per battery? So 3 of them should give me 8100 mAh?

 

[ventrue]

I see, the two of you are both very helpful and knowledgeable lol. I'm assuming that if each LED draws an average of 20 mA, and then I have 10 LED's, it would then stack up to about 200 mA. So if I had a battery setup with 1000 mAh, it would last about 5 hours? And that's assuming with those color changing LED's I was only using one color. Turning on multiple colors would increase the draw, and the batteries would drain faster. And, like you said, the current doesn't always stay constant, so I probably wouldn't get the whole 5 hours out of it, maybe 4 or so. With one color.

So, how many mAh is in those NiMH cell AA's? I found these -> http://www.photonlight.com/products...-AA-Batteries-%2d-4%2dPack,-NiMH-2700mAh.html
That claim to have 2700 mAh, is that per battery? So 3 of them should give me 8100 mAh?

Thanks, but thatdecate is the real expert here, I just try until it either melts, smells, smokes, sparks, burns or works (ever wonder why you get a discount when you buy ten of something instead of just the one you need? :-D)

How the voltages and currents add up depends on how you wire the LEDs. If you put things in a row, the current through them all is the same and the voltage drop across the whole row is the sum of the voltages of each part. If you have two example-LEDs with U=2V and I=20mA and hook them up cathode-to-anode, you will need 4V to power them, but the current will only be 20 mA. If you wire things up in parallel, the currents through each part add up, but the voltages don't. With the example-LEDs above, you'd need only 2V, but your battery would have to provide 40 mA. You can also combine the two, connecting several rows of LEDs parallel to your power source.

The same goes for wiring up several batteries. Hooking them up in a row gives you the sum of their voltage, but no additional charge, because the same discharge current goes through all of them at the same time. If you connect them in parallel, you get a higher charge, because each of them only has to provide a fraction of the discharge current, but without an increase in available voltage. For example, if you take four batteries with 1000 mAh and 1.5 V and connect + to - to create a row, you'll get one big battery with 6 V and 1000 mAh charge. If you connect all the + and - together, you get a big battery with 1.5 V and 4000 mAh charge. You can combine this as well.

Note that this does not change the amount of energy you need to power your setup for a given time, but it does help you find a convenient setup. You may be able to save a few wires by connecting LEDs that are in close procimity to each other in a row, or you could change money by using parts that have a lower current rating (that would be interesting if you needed a voltage regulator, for example).

I've created a little illustration for these examples, not sure if they're correct from the electronic viewpoint:



Not sure what colour changing LEDs you mean, but the datasheet should tell you the precise current and voltage that you need to make them happy.
The charge rating on those batteries is for one battery, yes.

 

[ShinigamiNG]

Hmm, that's really helpful. Thanks! And as for the color changing LED's, I meant the RGB LED's that I linked to a few posts back, or attempted to with my fail html post lol. So by hooking up 3 NiMH AA's in series, I'll get 3.4 volts, but if each battery is only say 2500 mAh, I'll only get 2500 mAh total right? But if I hooked them up in parallel, I would only get 1.2 volts, but 7500 mAh? Would that make the batteries last longer that way?

Sorry if this is answered in your diagrams, I'm currently at work so I haven't had a chance to look through them yet.

**EDIT**
Okay, checked out your diagrams, I think I understand what you're saying there. And the RGB LED's have a common cathode if I remember correctly, and then each of the 3 colors has its own anode. That way, with one LED and 3 switches wired up properly, I can have a range of 7 different colors. I want to use these all over the armor for the shield emitters, that way if I ever want a different color, I can just switch it easily. I'm just trying to find the best way to wire and power it so they would all be connected to the same 3 switches (based on color of course, all reds to switch one, all blues to switch two, and all greens to switch three) and hopefully the same power supply.

But for me, this is a little more compicated than wiring a few LED's in my helmet, or hooking up a 12v fan to a 9v battery and a switch lol. Hence why I'm posting in the noob forum, I'm a total noob when it comes to this stuff, but I find it really interesting, definitely something I would like to learn.

 

[ventrue]

Hmm, that's really helpful. Thanks! And as for the color changing LED's, I meant the RGB LED's that I linked to a few posts back, or attempted to with my fail html post lol. So by hooking up 3 NiMH AA's in series, I'll get 3.4 volts, but if each battery is only say 2500 mAh, I'll only get 2500 mAh total right? But if I hooked them up in parallel, I would only get 1.2 volts, but 7500 mAh? Would that make the batteries last longer that way?

Sorry if this is answered in your diagrams, I'm currently at work so I haven't had a chance to look through them yet.

**EDIT**
Okay, checked out your diagrams, I think I understand what you're saying there. And the RGB LED's have a common cathode if I remember correctly, and then each of the 3 colors has its own anode. That way, with one LED and 3 switches wired up properly, I can have a range of 7 different colors. I want to use these all over the armor for the shield emitters, that way if I ever want a different color, I can just switch it easily. I'm just trying to find the best way to wire and power it so they would all be connected to the same 3 switches (based on color of course, all reds to switch one, all blues to switch two, and all greens to switch three) and hopefully the same power supply.

But for me, this is a little more compicated than wiring a few LED's in my helmet, or hooking up a 12v fan to a 9v battery and a switch lol. Hence why I'm posting in the noob forum, I'm a total noob when it comes to this stuff, but I find it really interesting, definitely something I would like to learn.

Oh crap. I spelled "parallel" wrong in the pictures. How embarassing.

Anyways... I had only seen "100 pack" in that post with the HTML and assumed these were just red LEDs or so. They're surprisingly cheap... Make sure it's not some random garbage that didn't pass quality control somewhere else.

Well, as I said, the energy you have (and need over time) is the same, regardless of how you wire that stuff up. I'd say whichever variant wastes less energy makes the whole thing last a bit longer, but which one that is... no idea. Not sure if it's really noticeable either.

You can have an infinite number of colours with those LEDs. Using these just to have the option to maybe switch colours... I don't know. Seems like a bit of a waste to not actually use the ability to switch colours dynamically? Getting the stuff in between on and off for each colour just requires a few more parts and a little more work (did anyone say Arduino? ).

 

[Late to the meeting]

(I need to revise my posts better from now on.) Venture, why is it that when ever you post here I feel like I'm back in Jounior High School learning about ciurcitury for the first time... It's slightly demeening, and yet refreshing at the same time it helps to keep me sharp. so thanks for catching my mistake back there. oh and dont sell your self short, I dont disagree with you that Decade is a master in his own right but you have helped just as much as he has.

speaking of you Decade I have a question. a while back I asked about a spartan laser with a delay in the lighting so it looks like its charging where should I get the LED's from I want them high quality quantity dosn't matter and I need thenm bright like bright enough to stun a deer.... I live in the woods and they keep eating my frikin garden I just want to scare the crap out of them so thy dont come back the fact that its shaped like a spartan laser is just for kicks.... ok mabey not stun it but you now, scare the hell out of it .

 

[ShinigamiNG]

Oh crap. I spelled "parallel" wrong in the pictures. How embarassing.

Anyways... I had only seen "100 pack" in that post with the HTML and assumed these were just red LEDs or so. They're surprisingly cheap... Make sure it's not some random garbage that didn't pass quality control somewhere else.

Well, as I said, the energy you have (and need over time) is the same, regardless of how you wire that stuff up. I'd say whichever variant wastes less energy makes the whole thing last a bit longer, but which one that is... no idea. Not sure if it's really noticeable either.

You can have an infinite number of colours with those LEDs. Using these just to have the option to maybe switch colours... I don't know. Seems like a bit of a waste to not actually use the ability to switch colours dynamically? Getting the stuff in between on and off for each colour just requires a few more parts and a little more work (did anyone say Arduino? ).

Well, I have absolutely NO programming experience, though I had looked at Arduino boards before lol. Me and my small group are pretty happy with just the 7 colors we can get by manually mixing the lights with switches, but if we can get even more colors with an Arduino, it may be worth it. I imagine by controlling the amount of power going to each of the 3 colors with something like a potentiometer, then you could adjust the brightness of each LED, being able to further expand your color selection.

That would probably be something we would expand to later though. We've still got to finish our suits first, then worry about the fancy electronics. We'll just have simple lights and fans at first. Though, by simple, I mean those color changing LED's lol. And I hope to implement a voice amp and 2-way radio into the suit as well.

Which brings up another question, if I have a single headset, and a splitter to divide it to two outputs, then two remote PTT buttons, running to both a voice amp and standard 2-way radio, would I theoretically be able to use either output seperately by pressing the respective PTT button? That way, for example, I could press button 1 and talk to people nearby with the voice amp, and then with button 2 I could communicate with my other teammates either privately or across the convention from each other?

On paper, that seems like it would work. And that way I wouldn't need multiple headsets for each suit. But I'm guessing there is probably a way I could do that with Arduino too though? Lol.

Man, my posts are turning into walls... I apologize for that lol.

 

[ventrue]

(I need to revise my posts better from now on.) Venture, why is it that when ever you post here I feel like I'm back in Jounior High School learning about ciurcitury for the first time... It's slightly demeening, and yet refreshing at the same time it helps to keep me sharp. so thanks for catching my mistake back there. oh and dont sell your self short, I dont disagree with you that Decade is a master in his own right but you have helped just as much as he has.

Well, I don't know. Why don't you sit down and read your homework? :-D
Seriously. I have no intention of putting anybody down. I can stop if you want.

potentiometer
[...]
Which brings up another question, if I have a single headset, and a splitter to divide it to two outputs, then two remote PTT buttons, running to both a voice amp and standard 2-way radio, would I theoretically be able to use either output seperately by pressing the respective PTT button?

Yeah, for occasional colour changing, potentiometers would be a good choice. The Arduino would rather shine when it comes to letting the colours cycle all the time, or changing them according to temperature or your speed or something like that.

No idea about the sound thing, but I'm eager to read somebody else's answer.

 

[Dreadnaught]

Vent, you asked what I'd use that much power for... The answer is, say, 3 fans, 20 or so LED's, and maybe even a voice changer. The idea hit me sideways so I haven't really looked at it. It's just that I see people talking about AA and AAA and 9v batteries a lot. I just thought I'd see what you guys thought of that option? I think 16.8V and 5000 mAh should be sufficiend to power quite a bit, for quite a while...

 

[thatdecade]

a while back I asked about a spartan laser with a delay in the lighting so it looks like its charging where should I get the LED's from I want them high quality quantity dosn't matter and I need thenm bright like bright enough to stun a deer....

If you want a wicked bright LED, go with the luxeon III or IV. Seer your eyeballs bright. lol You can find luxeon I & II in common LED flashlights. Have a look at this kit here:
The Custom Saber Shop - Build Your Own Seoul P4 Electronics Kit

I want to use these all over the armor for the shield emitters, that way if I ever want a different color, I can just switch it easily. I'm just trying to find the best way to wire and power it so they would all be connected to the same 3 switches (based on color of course, all reds to switch one, all blues to switch two, and all greens to switch three) and hopefully the same power supply.

It sounds like you have a partially working setup already. Can you sketch up how you have it wired currently? After I see yours, I can post a modified sketch to expand.

We can get even more colors with an Arduino, it may be worth it.

The arduino tutorials that I've seen, lesson 1: light an LED and dim it. That is all you would need to do to color mix.

 

[ventrue]

Vent, you asked what I'd use that much power for... The answer is, say, 3 fans, 20 or so LED's, and maybe even a voice changer. The idea hit me sideways so I haven't really looked at it. It's just that I see people talking about AA and AAA and 9v batteries a lot. I just thought I'd see what you guys thought of that option? I think 16.8V and 5000 mAh should be sufficiend to power quite a bit, for quite a while...

Well, I favour AAs (and that whole form factor up and down the list) is because they are cheap, available everywhere (at least as alkalines, which might be an alternative depending on your setup) and rechargeable with pretty much any charger. No need for a special plug here. They also are single cells, which means that you can prolong their life with an intelligent charger. Battery packs usually make that difficult. I don't like nine volt batteries that much. They're useful if you need a high voltage without much hassle, but their charge is really low.

You can use these packs, of course, especially if you have them lying around anyways. But if you don't, then it's probably not the best solution.

 

[ShinigamiNG]

Thanks thatdecade, unfortunately, I don't have enough of my new suit finished to have anything wired yet... All of my ideas are still in my head or on paper in the planning stage. But I can go ahead and explain how I plan to go about holding everything together and wiring it all up. It will be a layered setup as follows:

First: Wear a base layer, some type of moisture wicking clothing, Under Armour brand or whatever. Preferably black, because you'll still see some of it underneath everything else.

Second: A harness/tactical chest rig such as http://www.airsoftpost.com/product_info.php?cPath=30_596&products_id=30910 We've already got a couple very similar to this lying around, one of my team members had some extra ones from when he was in the army. Basically we will be adding a few more straps, and of course a belt, since the one I linked only has the chest rig. But we'll add a tactical belt as well, to have drop down straps for the thighs.

Third: We will have a wiring setup that will be attached to the harness (most of it anyways) so we can put it all on at once. I plan to run the wires through some of that black tubing that flexes and bends, but doesn't bend to sharply so the wires won't get damaged. I think its some type of conduit or something, I dunno what its called, but I've seen it places lol. I plan to have all of the wires meet at the left forearm, and connect to the "Tacpad" there. The "conduit" will run up the outer side of my arm, so it doesn't kink when I bend my elbow, up behind my shoulder and split behind my shoulder blades, with one split going to my right arm, and another split going down my back. Possibly have a split going over my shoulders to power any lights on the front of the chest armor, or any fans I plan to put there (to help cool down my body core some) The split that goes down my back will split again at about waist level, and will wrap partway around my waist to go down the sides of my thighs, and then later the outer sides of my knees. All of this layer will be connected to the harness and will strap to my body. All of the wires will end in color coded quick connects for easy attachment to the armor later.

Fourth: I will have a layer of actual under armor, mostly for the stomach and lower back areas, shoulder and inner thighs. I haven't decided yet if this layer will also attach directly to the harness or not, I might be able to make all three of these layers one piece for ease of putting it on. But basically this layer will be made out of some type of soft, flexible, and breathable material to replicate the look of the under armor. Or, some parts of it may be down out of the EVA foam mats that a lot of people are using now. I've messed with them some, and they are pretty neat, thought it would probably be a mixture of those and fabric for dimension.

Fifth: The actual armor will then clip onto the harness, with adjustable nylon straps and back pack type clips. Then, the wires will be connected via the color-coded quick connects to the LED's and fans.

Theoretically, at this point, not only should my armor look pretty cool, but it will be functional as well (I'm hoping) The under armor, foam pads or whatever it will be made of, will help cover up the harness and a lot of the wiring. The black "conduit: will also hopefully blend in with the undersuit, and quite possibly just add to the look.

I will try to get some type of actual diagram drawn up for you, because I know this could be hard to understand through writing. I'm not even sure if I explained it that well lol.

AND I will look into some of those arduino tutorials, it might be useful for our suits in the long run.

Oh and *Edit* if anyone has any knowledge on whether or not my headset idea would work that was a few posts back, it would be greatly appreciated information I'll copy and paste that part of my post here too!

Which brings up another question, if I have a single headset, and a splitter to divide it to two outputs, then two remote PTT buttons, running to both a voice amp and standard 2-way radio, would I theoretically be able to use either output seperately by pressing the respective PTT button? That way, for example, I could press button 1 and talk to people nearby with the voice amp, and then with button 2 I could communicate with my other teammates either privately or across the convention from each other?

 

[Late to the meeting]

Did I ask you to stop? No that would be ignorant I just joking about it feeling demeening I thought it would be taken as funny, oh well. Just trying to give credit where its due.

 

[ventrue]

Did I ask you to stop? No that would be ignorant I just joking about it feeling demeening I thought it would be taken as funny, oh well. Just trying to give credit where its due.

Hey, don't worry. I got it that way ;-)

 

[Late to the meeting]

cool just making sure. yay three diggets *ding* achivement hoooray.

Decade sweet thanks but the armour lighting video in you window or what ever you call it might also have some ideas If I cut the heads off the one dollar book lights and made rings of then then sined them through a red filter along with the primary flash bulb that will simulate the firing of teh lazer. do you think that would work

 

[thatdecade]

I heard tacpad, got all excited and tuned out the rest. Sorry
http://www.405th.com/showthread.php/30092-Undersuit-Halo-Reach-(wip)

 

[Bighouse]

Couple of questions regarding LED's:

1. Do they get hot to the touch and, if so, how do you mount them to avoid heating up your helmut?
2. How do you focus the light? Flashlights have a parabolic mirror behind and around the lamp- is there a way to make these or a source available for small premade ones????

Thanks!

 

[thatdecade]

The average LED has a focusing lens built in and will not get hot. For information about the focus lens check the LED specifications for the Viewing Angle.

http://www.robotroom.com/RBFB.html

The brighter LEDs do NOT have a focusing lens built in and DO get hot, these require a heatsink. Pictured is a luxeon star LED, found in flashlights.

 

[Dreadnaught]

I picked up a few surface mount LEDs that I intend to use as lighing effects if they are both bright and diffuse enough. The site that I got them from was limited on data about them, and I was wondering what you guys thought about using them. Other than being incredibly small and hard to work with, I don't know much about them, at all.