LED advice needed

[Stigmorgan]

So I've got an idea for a product line I can possibly make and replicate that could sell very well at the shop and at craft fairs, because I want to sell it at the shop I want it to be battery operated to avoid the hassle of PAT testing etc, what I have in mind should work fine with 1 bright LED running from a battery, the kits I've looked at on Amazon all use "square" batteries, the tails are only 20cm long on the LEDs and theres no switch, so I guess I'll be looking at buying everything I need individually which I think is-
LED and housing grommet (I think maximum of 5mm ish)
Wire
Switch
Battery terminal/housing


Having never dabbled with electrics beyond changing a plug I'd welcome any advice/recommendations you guys can give

 

[John Brown]

The voltage you need for an LED depends on the colour, red are about 1.6 volts, green and blue are higher. White, IIRC, are also higher, as white light has a blue component. LEDs also need a current limiting resistor (or another method of controlling the current, but let's keep it simple). Some LEDs have a built it resistor, some don't.
Some more information about what you want to achieve would be helpful.

 

[Sideways]

I'll let someone else recommend a specific device but a thing called an LED driver IC or LED driver chip is a very small and simple to use component that will ensure your LED is fed a constant diet as your battery goes from full to empty.
They cost pennies so it would be worthwhile including one in your design.
You mention square batteries - I guess you mean the little 9v ones with two studs on the same end. Horrid things. 9V is actually much more than the LED needs (more like 1.6 to 2.5V) so it gives you the problem of getting rid of the excess and almost forces you to include a chip in the circuit.
A battery holder for two AA or AAA cells would be better IMO. AA and AAA are more easily available, customers are more likely to have them around the house for other devices and if you adopt a driver chip, that will adapt automatically if someone wants to use rechargeable batteries in it.
You next step up would be a small 3.6v rechargeable cell and a module that handles power in, LED supply and a socket to charge up from USB. This sort of thing is commodity tech so it should all be cheap compared to the handmade element.

This tiny nightlight has usb charging and a few hours runtime and it's only an inch across ...

 

[Stigmorgan]

https://www.amazon.co.uk/RUNCCI-YUN...0f69ddfb7f4e3951bcf4d855dc0c73ec&gad_source=1
This is the kit I found, I only want white, longer wires and a different battery

 

[Gerry]

Those look to be sets of 10 led's wired in series so they can run off the 9v battery. How many led's do you need for each project and what battery do you intend to use?

Gerry

 

[Stigmorgan]

Those look to be sets of 10 led's wired in series so they can run off the 9v battery. How many led's do you need for each project and what battery do you intend to use?

Gerry

I only need 1 LED but I may add more as I add different designs, as for the battery I don't really know, the LED tealights I have use the C2032 flat round battery connected by a simple contact switch, I've seen holders for them so they are also an option.
Sorry I'm being a little vague on what I'm doing, I've spent days searching and haven't found what I've got in mind available anywhere (there may be good reason, there's a few design challenges involved) and I've put stuff online before to find others on YouTube making it shortly after, in simplest form I want to mount an LED and run the cables through a 6to10mm hole up to 300mm deep to the battery and switch in the base.

 

[Sideways]

My guess is that the LED's in your link aren't wired in bunches. You have 60 separate leds and 10 holders. Combine in parallel as you will. The black heat shrink where the wires are soldered to the LEDs have a bulge in them. There will be a resistor in there that gets rid of the 7.x excess volts of the battery by warming up.
These are cheap as chips but as elegant as furniture made from recycled pallet wood nailed together...

 

[Stigmorgan]

My guess is that the LED's in your link aren't wired in bunches. You have 60 separate leds and 10 holders. Combine in parallel as you will. The black heat shrink where the wires are soldered to the LEDs have a bulge in them. There will be a resistor in there that gets rid of the 7.x excess volts of the battery by warming up.
These are cheap as chips but as elegant as furniture made from recycled pallet wood nailed together...

They were what came up when I searched for LED kits, I'm happy to buy everything individually, just want to make sure I know what I need first and do a decent job of it.

 

[Yojevol]

Here you are Stig, these may be of use:-

A bag of white LED's, plastic holders and matching resistors.
These were purchased for a model railway control panel which never came to fruition. As such they are designed to run off 12V. This may not be what you want as a power supply but they may be useful in developing your idea.
PM me if interested
Brian

 

[Stigmorgan]

Here you are Stig, these may be of use:-
View attachment 183647

A bag of white LED's, plastic holders and matching resistors.
These were purchased for a model railway control panel which never came to fruition. As such they are designed to run off 12V. This may not be what you want as a power supply but they may be useful in developing your idea.
PM me if interested
Brian

Thanks Brian, I may take you up on that once I've got a better understanding of things

 

[MorrisWoodman12]

@Stigmorgan . Are you trying to provide illumination as in a light for people to see by or is the white LED just a point of light for an artistic effect? As this determines the power of the LED required it will determine the size of the LED, the current through it and the size/lifetime of the battery.

 

[Stigmorgan]

Artistic effect, only needs to be bright enough to make very thin wood glow in a similar way as this LED tea light ...

 

[MorrisWoodman12]

It looks as though you'll need a fairly wide angle LED for that sort of job but not an extremely bright one. So it will be running at a moderate current. Obviously you'll have to experiment to find just how much current/brightness is needed. More current = higher brightness = shorter battery life.
Battery capacity, which will determine battery life, is measured in mAhr (milliamp hours). Divide the mAh by the running current to get a good approximation of lifetime.
Hope I'm not teaching my grandmother to suck eggs!
If you need any help you can always PM me.
Have fun
Martin

 

[Stigmorgan]

It looks as though you'll need a fairly wide angle LED for that sort of job but not an extremely bright one. So it will be running at a moderate current. Obviously you'll have to experiment to find just how much current/brightness is needed. More current = higher brightness = shorter battery life.
Battery capacity, which will determine battery life, is measured in mAhr (milliamp hours). Divide the mAh by the running current to get a good approximation of lifetime.
Hope I'm not teaching my grandmother to suck eggs!
If you need any help you can always PM me.
Have fun
Martin

Electrics go way over my head, my knowledge is almost as basic as - small zap = ouch, big zap = dead

 

[MorrisWoodman12]

A couple of typical lifetime calculations. IF you end up running the LEDs at 20mA then with a typical 9V PP3 square battery of 300 to 400 mAh lifetime will be 15 to 20 hours. A typical AA cell is 1000 to 1500 mAh giving a lifetime of 50 to 75 hours. Of course doubling the current will halve the lifetime.

 

[Spectric]

For a single LED you will be given the required forward current and voltage, ie 20mA @ 3V and if you have a 5 volt supply then the resister required is given by

(5-3)/0.020 = 100 ohms

This is ok for some applications but the resister will disipate energy in the form of heat so with a higher voltage supply this can get excessive. The better solution is to use a dedicated Ic or linear regulator that can power strings of LED's.

Microchip produce such IC's and the CL25 is just one example. This can power a string of LEDs and maintain the required constant current.

 

[MorrisWoodman12]

Spectric's Microchip CL25 is a great little device and very simple to use. Be aware though that it needs at least 5V across it while it's operating so with, say, a 2V LED you will have to have at least 7V input so a PP3 battery (9V) or seven AA's in series (7V5).

 

[John Brown]

Are you after the flickering effect, like the video clip you posted?

 

[Stigmorgan]

The flickering effect is a bonus but not essential.
Was chatting with one of our new dads this morning, turns out he is an electrician and just set up his own firm, he said we can meet up for a coffee and he will look at what I want, even said he will do the pat tests for me for beer money if I decide to go the powered route