Kim, I'm in Texas, US. I was indeed thinking of getting one of those hot air guns for heat shrinking, but most I've seen on Amazon were sort of expensive or otherwise I wasn't sure about their quality. Which cheap one do you think is pretty good? Thanks for the LED info.



That Goldmine has quite a few different style LEDs, thanks for mentioning it and Jameco. Since I was looking into atmospheric glow and low light "soft white" or "warm white" LEDs would be best, but not all brands/resellers seem to have them. Goldmine does have some, but most of them are already quite bright to begin with. The Chanzon ones I found on Amazon do have lower output so they may be better for what I'll use them for.

One option would be to cut out the individual LEDs from LED strips as I've seen some do, but I was thinking I may stay away from that because I would like the LEDs to be exchangeable more easily, in case they burn out.

I think I'm about ready to order some stuff and once that gets in I'm going to have to experiment I haven't started yet but this seems fun already. The one thing I wasn't sure about was power supplies. I am going to experiment with 5v phone chargers but thought I might get a Bench Power Supply too, but I don't know if it is very useful to get a cheaper one (like around $60 range).

You are not required to run them at the recommended brightness. if they are brighter at 20 mA they will be a suitable brightness at perhaps 2 mA as opposed to 5 or 10 mA with a less efficient LED.

Re: Power supply

Work with the power supply you will use in the application.

I use "wall wart" (phone chargers and such) power supplies for all my projects. I have been collecting them for years from yard sales and second hand stores. I usually pay less than a dollar for them. I do not own a bench grade power supply. What ever I need I can find something among my stock.

 

Kim, I'm in Texas, US. I was indeed thinking of getting one of those hot air guns for heat shrinking, but most I've seen on Amazon were sort of expensive or otherwise I wasn't sure about their quality. Which cheap one do you think is pretty good? Thanks for the LED info.



That Goldmine has quite a few different style LEDs, thanks for mentioning it and Jameco. Since I was looking into atmospheric glow and low light "soft white" or "warm white" LEDs would be best, but not all brands/resellers seem to have them. Goldmine does have some, but most of them are already quite bright to begin with. The Chanzon ones I found on Amazon do have lower output so they may be better for what I'll use them for.

One option would be to cut out the individual LEDs from LED strips as I've seen some do, but I was thinking I may stay away from that because I would like the LEDs to be exchangeable more easily, in case they burn out.

I think I'm about ready to order some stuff and once that gets in I'm going to have to experiment I haven't started yet but this seems fun already. The one thing I wasn't sure about was power supplies. I am going to experiment with 5v phone chargers but thought I might get a Bench Power Supply too, but I don't know if it is very useful to get a cheaper one (like around $60 range).

"Atmospheric glow"?
Constellations? white LEDs of different sizes? Maybe a few red for red giants. The eye of the bull in Taurus is red.
Fiber optics can give you tiny (1 mm or less) dots of distant background stars.

 

Thanks for the tips!

Atmospheric glow, I meant candle-like light (as in, a nice atmosphere), sorry about that!

But you just gave me a great idea, thanks I will certainly try the fiberoptics thing, I already have an idea.

 

With those indicator LEDs (single ones), do they make any sockets or inlets for inserting the cathode/anode legs? I was wondering if it was possible to just install LEDs without soldering, so that the LED could be easily replaced. Kind of like placing an LED into a solderless bread board, but then only 2 holes for the LED legs. I haven't seen anything like that except on bread boards but I think that would be a good idea for how I plan to use them. I'm thinking if an LED somehow gives up the ghost some years down the line, people could just pull the old LED out and place a new one in. I could provide an LED as a spare, with shorter, equal-length legs for insertion).

 

Most non-hobbyist just wave a lit match under heat-shrink tube, rather than a heat gun. It is much less expensive than a full-blown soldering station with a heat gun/wand, especially for occasional use.

You could use a female micro USB receptacle, various standard values of resistors in the 330 - 2,200 ohm range of 1/4 watt rating, one for each LED you plan to attach to +5V, some jumper wires with clips on the end or a small proto-board for prototyping circuits (this should help you with initial experimentation, http://www.banggood.com/Prototype-B...ard-65pcs-Breadboard-Jump-Cable-p-948106.html) . Once you find what you like and works, you can come back with your values and get help on reducing the number of resistors needed if you need to light many LEDs for your project. Once you have your final configuration, you could use a dedicated Printed circuit soldering board to place your input connector, your resistors and output wires to the LEDs.

I recommend you keep it simple (using a phone charger and cable is an excellent approach), and try things out, as you start out. It will save you a ton of dinero. As you gain experience and want to use LEDs more and more for other projects, you could expand your equipment for soldering, heat shrink, variable voltage/constant current power supply and so on, but start with baby steps for equipment.

 

Thanks, Inspironator, that's what I figured about the heat gun for now, too. I did order that soldering station ($59) I linked to earlier because I have this archaic soldering iron with unwieldy cord and no control. I also got some wire and tips and third hand, etc., and before checkout I found out they give a gift along with orders over $50 and one of them was a little butane torch/soldering tool so maybe that will work for heat shrinking. I saw they had one mini torch on Amazon that had a special tip that would divert the direct flame of the torch but would blow hot air, especially for heat shrink. But the free gift one I am getting does not have that so it would probably easily burn the wire/shrink if I'm not careful.

Yes, I had seen those female micro USB receptacles on Amazon. The only thing I didn't know was how to connect it to the rest of the circuitry; do I just solder the leads straight to the LED and resistor, or does using a micro USB receptacle require some additional things? Then, because the micro USB receptacles are so small, do I need to secure them to a piece of circuit board or do I just epoxy it into the whole in the wood/piece? Not sure how that is normally done.

I agree to keep it simple at first. I think what I'm trying to do at this point is pretty simple anyway. Last night I was looking at Bench Power Supplies but I really don't know what I would use them for at this point so I decided not to get one. I found a little kit with bread board, wires, resistors, etc., for pretty cheap so I'm getting that too so I have various basic parts to play around with and learn from.

One thing that kind of worried me about using phone chargers is that several manufacturers (Samsung, for example) now make phone chargers with dual voltage mode; one with 5v @ 2a and one 9v @ 1.67a. Here's a pic of it:

The way this 9v function is described is that the phone has tech built in to sense whether a charger supports this fast charging 9v feature and can then use it. What I don't know is what triggers the charger to release 9v, if it even works that way.

 

With those indicator LEDs (single ones), do they make any sockets or inlets for inserting the cathode/anode legs? I was wondering if it was possible to just install LEDs without soldering, so that the LED could be easily replaced. Kind of like placing an LED into a solderless bread board, but then only 2 holes for the LED legs. I haven't seen anything like that except on bread boards but I think that would be a good idea for how I plan to use them. I'm thinking if an LED somehow gives up the ghost some years down the line, people could just pull the old LED out and place a new one in. I could provide an LED as a spare, with shorter, equal-length legs for insertion).

SURE, there are IC sockets (http://www.banggood.com/10Pcs-8-Pin...r-Type-Socket-Dual-Wipe-Contact-p-922882.html) or header sockets (http://www.banggood.com/5Pcs-40-Pin...eader-IC-Socket-DIP-SIP-Adaptor-p-944243.html) you can cut to the length for what you need, that can be used. They are made to allow easy replacement of Integrated circuits, interconnect cables... You could get one for an 8 pin IC, and use a single or up to 4 LEDs.

 

With those indicator LEDs (single ones), do they make any sockets or inlets for inserting the cathode/anode legs? I was wondering if it was possible to just install LEDs without soldering, so that the LED could be easily replaced. Kind of like placing an LED into a solderless bread board, but then only 2 holes for the LED legs. I haven't seen anything like that except on bread boards but I think that would be a good idea for how I plan to use them. I'm thinking if an LED somehow gives up the ghost some years down the line, people could just pull the old LED out and place a new one in. I could provide an LED as a spare, with shorter, equal-length legs for insertion).

Yes, they do make LED holders. They even make LEDs in the shape of a flame that flicker like a candle. Electronic Goldmine carries them.
If you have a local Dollar Tree store you can probably buy LED candles four for a dollar.

 

The first socket @Inspironator posted would likely yield only two usable 2-pin sockets. When cutting that type apart, you often damage a pair of sockets, making them unusable. Ask me how I know...

 

Inspironator, would I just solder the wires to/from those round hole header ic sockets directly to those legs on the header sockets? I noticed with the other sockets (first link you gave) it has those sharp legs that look like they're meant to fit into circuit boards. So it seems the round hole header ic sockets would be better for what I'm doing, but I wasn't sure what would be an acceptable way to connect them to the wires running to/from them. Can I just straight solder the wires to those round hole socket legs?

hp1729, yes, I have some of those flame-like LEDs on batteries but for what I'm doing it's not required that the LEDs have the shape of a flame, just that they mimick the glow of a candle in terms of their color and output. So I'm just looking for ways to include relatively dim, warm white light to projects. Just like having candle light in front of an image at night, that sort of light. But I want to integrate them into pieces, so for example a wooden box with a fresco type image on the back panel; I want to integrate an LED into the box/frame that shines toward the back panel with the image, as to illuminate it like a candle or soft light would. I want to conceal the LED from direct view so you can't directly see it from looking at the project, but you will see the light illuminating the back panel of the box/frame. So I want to angle the LED to shine toward the back panel, so you would never look straight into the LED or be able to see it directly, just the glow on the back panel would be visible. Sorry, it's hard to explain but I'm not looking for any special shape of LED, just to create a somewhat dim, warm glow to illuminate the art piece.

Of course, I'll have to run the wires and components in a concealed way, so that's another challenge and so for the most part the smaller the components the better. I do want to make sure I do things in a more or less proper way but since a lot of this stuff is new to me I don't yet know how those components are normally hooked up to each other.

BTW, I know heat shrink tubing is used for covering wire connections, but isn't there some kind of liquid for covering connections as well? I haven't seen it but I figured there would be some liquid coating for connections too, kind of like that liquid rubber you can paint over metal hangers or something.

 

Figure out about how many LEDs you want to use. Plan on driving your LEDs with 15 mA or less current if you want it to not get bright light. I doubt that you will need to use that Samsung Charger. it is like using a sledge hammer when a small hammer will do the job. Go with the low current phone charger as your first choice. You can keep it simple that way. But if you only have that Samsung phone charger, which I'm fairly sure is a smart charger, given the 2 voltages, I believe you can enable 1A of charge current very simply. Connect pins 2 to 3. The other two will be positive 5V and ground.

 

Figure out about how many LEDs you want to use. Plan on driving your LEDs with 15 mA or less current if you want it to not get bright light. I doubt that you will need to use that Samsung Charger. it is like using a sledge hammer when a small hammer will do the job. Go with the low current phone charger as your first choice. You can keep it simple that way.

Yes, I should have explained that better: I meant in case people use one of those dual voltage chargers (which I wouldn't recommend or include). I'd like to be able to say to whoever owns the piece, "you can hook it up to any USB phone charger" without people having to determine what type of charger they have. I was debating whether or not to provide chargers with the pieces (I probably should) but I would like for people to be able to use any USB-based phone charger. The chances of people using different chargers would be greatly reduced by including a charger and cable, but people may still think they're interchangeable and use another charger (or the charger I include could break and people will use another one). So that is why I was trying to figure out what the possible ramifications might be of those dual voltage chargers on my application. I will test it once I get my supplies in, but I thought maybe someone had heard about those dual voltage chargers and might know something about them.

I did think about including USB cables with switches in them (like here) so I wouldn't have to install a switch into the wood as well. I further thought about adding a touch switch or a light sensing switch to the pieces, but the way I'm looking at this is that the more potential failure points I include, the more likely it is that the life-span of the light function will be shortened. So if I had a switch in the USB cable, that could be replaced externally. Then, along with the LEDs being able to be replaced easily by using those round hole sockets, it should last a long time.

You can keep it simple that way. But if you only have that Samsung phone charger, which I'm fairly sure is a smart charger, given the 2 voltages, I believe you can enable 1A of charge current very simply. Connect pins 2 to 3. The other two will be positive 5V and ground.

Do you mean to connect pins 2 to 3 of the female micro USB in that I'd use in my pieces, or do you mean something else?

EDIT: Hmm, seems like USB cables with integrated switches are hard to find. The ones I did find had some reviews that stated there was a resistor in the switch, causing a voltage cut of 0.5v. So that's not going to work because I don't want to make the function and brightness of the light dependent on a cable. I know inline switches exist but is there one anyone knows of that might work on a USB cable? I was thinking of making an inline switch into generic usb cables instead, but it would have to look OK and work well.

 

Yes, I should have explained that better: I meant in case people use one of those dual voltage chargers (which I wouldn't recommend or include). I'd like to be able to say to whoever owns the piece, "you can hook it up to any USB phone charger" without people having to determine what type of charger they have. I was debating whether or not to provide chargers with the pieces (I probably should) but I would like for people to be able to use any USB-based phone charger. The chances of people using different chargers would be greatly reduced by including a charger and cable, but people may still think they're interchangeable and use another charger (or the charger I include could break and people will use another one). So that is why I was trying to figure out what the possible ramifications might be of those dual voltage chargers on my application. I will test it once I get my supplies in, but I thought maybe someone had heard about those dual voltage chargers and might know something about them.

I did think about including USB cables with switches in them (like here) so I wouldn't have to install a switch into the wood as well. I further thought about adding a touch switch or a light sensing switch to the pieces, but the way I'm looking at this is that the more potential failure points I include, the more likely it is that the life-span of the light function will be shortened. So if I had a switch in the USB cable, that could be replaced externally. Then, along with the LEDs being able to be replaced easily by using those round hole sockets, it should last a long time.



Do you mean to connect pins 2 to 3 of the female micro USB in that I'd use in my pieces, or do you mean something else?

EDIT: Hmm, seems like USB cables with integrated switches are hard to find. The ones I did find had some reviews that stated there was a resistor in the switch, causing a voltage cut of 0.5v. So that's not going to work because I don't want to make the function and brightness of the light dependent on a cable. I know inline switches exist but is there one anyone knows of that might work on a USB cable? I was thinking of making an inline switch into generic usb cables instead, but it would have to look OK and work well.

So any 5 Volt USB style phone charger capable of 350 mA, or so ... that is just about all currently on the market, isn't it?

 

What I was trying to say is that next to the regular 5v chargers, there are now also dual voltage chargers like the Samsung one of which I posted the picture, which can do 9v at 1.6a. Those have been included with smartphones since at least the Samsung Galaxy S6 (and S7) so those charger will be everywhere already. But the way I understand it, the 9v mode only gets elicited from the charger when a compatible phone (that can fast-charge) is hooked up to it. I'm not sure about, so I was wondering if anyone knew anything about that. I think it will be OK, but I'll have to test it as I do have 2 of those 5/9v chargers here.

 

What I was trying to say is that next to the regular 5v chargers, there are now also dual voltage chargers like the Samsung one of which I posted the picture, which can do 9v at 1.6a. Those have been included with smartphones since at least the Samsung Galaxy S6 (and S7) so those charger will be everywhere already. But the way I understand it, the 9v mode only gets elicited from the charger when a compatible phone (that can fast-charge) is hooked up to it. I'm not sure about, so I was wondering if anyone knew anything about that. I think it will be OK, but I'll have to test it as I do have 2 of those 5/9v chargers here.

\

Thanks for the info. I don't have such a phone and wasn't aware of those type of power supplies.

 

The LED does not care what the amperage capacity of the power supply is. They only care about how much current they are getting.
As for the resistor in series with the LED that exactly what you want and to figure that out just subtract your LED's working voltage from the power supply voltage, in your case 5 volts, and use Ohms law to calculate what current you want based on the remain voltage difference between the LED and the power supply.

For example, if you have a white LED that has 3.6-volt forward drop and your power supply is 5 volts you have a 1.4-volt difference.

Given that if your LED can handle up to 30 milliamps you just divide your 1.4 volt differential by .030 and you come up with a resistance value of 46.66 ohms which you can round up to the next common higher resistor value you can find like a 50 ohm.

As for your power supply amp ratings that just the maximum current they can supply so if you have a 1.5 amp supply you could run up to 1500/30 = 50 LEDS at 30 milliamps each off of it without overloading it.

 

Hi All,

I'm new to the forum and I've been trying to get my head around some basic electronics stuff but I'm having a hard time figuring out what I need for my specific projects.

What I'm trying to do is use atmospheric, low light LED's in some art/craft projects I'm doing. Basically, I'm trying to integrate LED's in wood and other projects. The light does not have to bright, and in most cases rather dim and soft. I'm thinking a single LED bulb (or short strip) would suffice.

The other requirement is that I would be able to use as a power supply the typical USB style charger as may come with your smartphone or tablet or what have you.

It looks like most of these chargers are 5v output, and range between 750a and 1.5a, although I have a Samsung charger that lists 5.0v -- 2a.

My plan was to integrate microUSB ports into the wooden craft pieces, so that you could just plug in a microUSB cable into the piece and plug the other end into one of those phone chargers (some charges have permanently attached wires with microUSB ends). I would also have to integrate an on/off switch into the piece so that the usb wire could remain hooked up.

In trying to figure out what I would need specifically for this. Here are some questions I have:

a) Since the various phone chargers have different amp specifications for the output (750ma, 1a, even 2a) does this mean I cannot regulate the light output of the LED(s)?

b) I have read about resistors and the calculations regarding Ohm's law and the LED(s) used, but would this be thrown off if different phone chargers would be used like 750ma or 1.5a?

c) I have read about one way to dim LED's by means of a variable resistor or potentiometer. Is this a safe and reliable method? I read some people consider it wasteful as it results in waster energy as heat (and heat is always considered bad for longevity).

d) Since I'm looking to dim the LED's brightness to atmospheric levels (like a candle light, basically) is this bad for the LED as far as longevity?

e) Would it be best to use a single LED with prongs or would it be better to use a partial strip of 3 LED's?

I won't make this too long to start but hopefully you guys got an idea of what I'm trying to do and if this is possible or not. Basically those USB chargers would be my power supply of choice because it would allow you to plug in the art pieces easily, anywhere, since those USB chargers are everywhere. One other consideration I had was ability to change out LED's in case they burn out or go kaput. So I was thinking this would be easiest with those single LED's with prongs. I guess that would be another question, which would be the most reliable LED's.

Thanks for any input!

Hi All,

I'm new to the forum and I've been trying to get my head around some basic electronics stuff but I'm having a hard time figuring out what I need for my specific projects.

What I'm trying to do is use atmospheric, low light LED's in some art/craft projects I'm doing. Basically, I'm trying to integrate LED's in wood and other projects. The light does not have to bright, and in most cases rather dim and soft. I'm thinking a single LED bulb (or short strip) would suffice.

The other requirement is that I would be able to use as a power supply the typical USB style charger as may come with your smartphone or tablet or what have you.

It looks like most of these chargers are 5v output, and range between 750a and 1.5a, although I have a Samsung charger that lists 5.0v -- 2a.

My plan was to integrate microUSB ports into the wooden craft pieces, so that you could just plug in a microUSB cable into the piece and plug the other end into one of those phone chargers (some charges have permanently attached wires with microUSB ends). I would also have to integrate an on/off switch into the piece so that the usb wire could remain hooked up.

In trying to figure out what I would need specifically for this. Here are some questions I have:

a) Since the various phone chargers have different amp specifications for the output (750ma, 1a, even 2a) does this mean I cannot regulate the light output of the LED(s)?

b) I have read about resistors and the calculations regarding Ohm's law and the LED(s) used, but would this be thrown off if different phone chargers would be used like 750ma or 1.5a?

c) I have read about one way to dim LED's by means of a variable resistor or potentiometer. Is this a safe and reliable method? I read some people consider it wasteful as it results in waster energy as heat (and heat is always considered bad for longevity).

d) Since I'm looking to dim the LED's brightness to atmospheric levels (like a candle light, basically) is this bad for the LED as far as longevity?

e) Would it be best to use a single LED with prongs or would it be better to use a partial strip of 3 LED's?

I won't make this too long to start but hopefully you guys got an idea of what I'm trying to do and if this is possible or not. Basically those USB chargers would be my power supply of choice because it would allow you to plug in the art pieces easily, anywhere, since those USB chargers are everywhere. One other consideration I had was ability to change out LED's in case they burn out or go kaput. So I was thinking this would be easiest with those single LED's with prongs. I guess that would be another question, which would be the most reliable LED's.

Thanks for any input!

The most obvious resistor would be a 47 ohm since there not too many 50 ohm resistors available. . . . . .

 

So I just tested 3 chargers, two of them were 5v 2a and one the dual voltage one (5v 2a and 9v 1.6a). The dual voltage 5/9v charger does read as 5v on the multimeter, so I think even those will work as 5v when just hooking up the black and red wires.

In the USB cable I cut open there are 4 wires present, and a wire shield. There are some variants in USB cables but in my example the black and red are negative current (or ground) and power, respectively. And green and white are negative and positive data wires. So to get the power only use the red and black wires, which appears to results in default 5v mode on those dual voltage chargers. So unless there is a fast-charge capable phone or tablet connected I think the default output of those chargers defaults to 5v.

The Micro USB receptacles also have 5 leads coming out of the back, so I think all that would need to be done is to hook up black and red (which are the outer two leads). The challenge for me is going to be finding receptacles that are long enough so they will fit in the routed-out wood without becoming too recessed.

 

Correct as far as it goes. That 3.6 V is at the rated current of 20 mA, or what ever. At 5 mA it could be only 3.0 Volts so you need to adjust the resistor accordingly. Most complete data sheets supply a chart showing voltage at different currents. If it doesn't, make your own chart.

 

You are not required to run them at the recommended brightness. if they are brighter at 20 mA they will be a suitable brightness at perhaps 2 mA as opposed to 5 or 10 mA with a less efficient LED.

Re: Power supply

Work with the power supply you will use in the application.

I use "wall wart" (phone chargers and such) power supplies for all my projects. I have been collecting them for years from yard sales and second hand stores. I usually pay less than a dollar for them. I do not own a bench grade power supply. What ever I need I can find something among my stock.