Major Newbie - wiring flicker LED's for a hobby kit

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
Hi. I want to say at the outset that I searched both Google and the forums here like crazy and couldn't find an answer that quite fit my situation. Or if I did, I couldn't translate it to my project. Pretty sure what I'm looking for isn't difficult for people who know even a little more than I do (almost nothing) about electronics. So here goes.

I have a book nook kit that is supposed to look like a firefly garden. It came with the items in the first photo. 2 of the strings of lights have 5 lights, the last one has 6, and then there's a single one. The way you're supposed to assemble all this is to take all the grey wires from all the lights (including the single LED), and connect them to the grey wire on the circuit board, then take all the white wires from the lights and connect them to the white wire on the circuit board. I understand this.
IMG_20240228_170706557.jpg

The single light will be stuck through a hole on the bottom of a panel. The rest of the lights will be stuck through holes further up on the panel. The wires come out the back, with the battery circuit board and switch mounted inside the nook. As in this diagram (I didn't bother drawing all the lines representing the wires).
Firefly-Garden-Layout.jpg

But I don't want to use their lights, they just light up and don't do anything. I want lights that actually pulse on and off like a firefly. I've searched and searched, and can't find any LEDs that blink on, then blink off randomly, only strings that ALL of them flash off and on at the same time. So the closest I can find are ones that flicker such as these. Still not ideal, but better than anything else I've found (unless someone can point me towards something that does what I'm after). So what I'm thinking I need is 16 of the 3mm flicker LED's from the link, a power source, and a switch. My problem is, I don't know what to use as a power source because I am not knowledgeable enough to figure out what it'd need in battery power. Also, I don't know the best way to wire it all together. Do I connect all of the lights individually to a connection on the power source with the switch in the appropriate place (I'm assuming between the positive connection on the power source to the positive wire of the lights), or do I connect the led's to each other in a chain, with the resulting start and end wires hooked up to the power source appropriately (including the switch).

I much appreciate any help I can get here. The closest I've come to this is wiring a motor to a wooden automaton that's supposed to be hand cranked. So no real experience with lighting. Thanks!
 

dl324

Joined Mar 30, 2015
16,896
Welcome to AAC!
My problem is, I don't know what to use as a power source because I am not knowledgeable enough to figure out what it'd need in battery power.
The LEDs you want to use are rated at 12V/2mA 20mA. You wire them all in parallel and select a 12V power source that can provide 340mA for as long as you want the LEDs to operate.
EDIT: Corrected typo.

If you don't want to power from an AC adapter, select a battery chemistry that has the mAh capacity you want. You can experiment with one of the LEDs to find the voltage range that gives you the brightness you want. Then select a battery chemistry that you can put in series to get that voltage. 12V sealed lead acid is an obvious choice. Fully charged voltage will be around 12.6V, so make sure your LEDs will tolerate it.
 
Last edited:

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
Welcome to AAC!

The LEDs you want to use are rated at 12V/2mA. You wire them all in parallel and select a 12V power source that can provide 340mA for as long as you want the LEDs to operate.

If you don't want to power from an AC adapter, select a battery chemistry that has the mAh capacity you want. You can experiment with one of the LEDs to find the voltage range that gives you the brightness you want. Then select a battery chemistry that you can put in series to get that voltage. 12V sealed lead acid is an obvious choice. Fully charged voltage will be around 12.6V, so make sure your LEDs will tolerate it.

First - thanks for the welcome.

Next: I wanted to edit my post to include the fact that the linked led's have built in resistors, in case that matters. But I can't edit it, so hopefully stating it here helps.

Next - I am pretty sure I didn't understand most if any of that. I really need it spelled out in simple terms. I kept trying to respond to this saying, "Ok, so you're saying I should connect A to B and then to C" and it just sounded wrong.

As far as the power source, I do have on hand these battery packs. I'm assuming one of these will work, I just have to use the one that gives the appropriate amount of brightness? I also have rocker switches, or the one that's included with this kit.

Sorry if I'm ignorant. I try to figure things out on my own usually. I'm just shy of messing around with electrical too much, even if it is just battery powered small projects.
 

dl324

Joined Mar 30, 2015
16,896
Next: I wanted to edit my post to include the fact that the linked led's have built in resistors, in case that matters. But I can't edit it, so hopefully stating it here helps.
There may be a feature that prevents new members from editing posts after a certain time. I know all members are restricted from editing private messages after about 10 minutes.

I assumed that there was a resistor, or other circuitry, to limit current because there are no LEDs that have a forward voltage of 12V and can tolerate any voltage variation without that.
I am pretty sure I didn't understand most if any of that. I really need it spelled out in simple terms.
The LEDs you referenced have 2 wires; a positive (anode) and negative (cathode). You have to get the polarity right or they won't turn on.

You wire all of anodes together and all of the cathodes together. The anodes go to the positive terminal of your battery pack and the cathodes go to the negative.

If you have a switch, you put the switch between the battery and the anodes. You can do it the other way, but the way I mentioned is the usual way.
As far as the power source, I do have on hand these battery packs.
You'll need 8 AA batteries to get 12V.
Sorry if I'm ignorant. I try to figure things out on my own usually. I'm just shy of messing around with electrical too much, even if it is just battery powered small projects.
No problem. People of all levels frequent AAC and no one was born knowing anything about electronics.
 
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Ya’akov

Joined Jan 27, 2019
9,098
Hi. I want to say at the outset that I searched both Google and the forums here like crazy and couldn't find an answer that quite fit my situation. Or if I did, I couldn't translate it to my project. Pretty sure what I'm looking for isn't difficult for people who know even a little more than I do (almost nothing) about electronics. So here goes.

I have a book nook kit that is supposed to look like a firefly garden. It came with the items in the first photo. 2 of the strings of lights have 5 lights, the last one has 6, and then there's a single one. The way you're supposed to assemble all this is to take all the grey wires from all the lights (including the single LED), and connect them to the grey wire on the circuit board, then take all the white wires from the lights and connect them to the white wire on the circuit board. I understand this.
View attachment 316469

The single light will be stuck through a hole on the bottom of a panel. The rest of the lights will be stuck through holes further up on the panel. The wires come out the back, with the battery circuit board and switch mounted inside the nook. As in this diagram (I didn't bother drawing all the lines representing the wires).
View attachment 316470

But I don't want to use their lights, they just light up and don't do anything. I want lights that actually pulse on and off like a firefly. I've searched and searched, and can't find any LEDs that blink on, then blink off randomly, only strings that ALL of them flash off and on at the same time. So the closest I can find are ones that flicker such as these. Still not ideal, but better than anything else I've found (unless someone can point me towards something that does what I'm after). So what I'm thinking I need is 16 of the 3mm flicker LED's from the link, a power source, and a switch. My problem is, I don't know what to use as a power source because I am not knowledgeable enough to figure out what it'd need in battery power. Also, I don't know the best way to wire it all together. Do I connect all of the lights individually to a connection on the power source with the switch in the appropriate place (I'm assuming between the positive connection on the power source to the positive wire of the lights), or do I connect the led's to each other in a chain, with the resulting start and end wires hooked up to the power source appropriately (including the switch).

I much appreciate any help I can get here. The closest I've come to this is wiring a motor to a wooden automaton that's supposed to be hand cranked. So no real experience with lighting. Thanks!
Welcome to AAC.

You might consider these SMD (Surface Mount Device) blinking white LEDs with attached pig tails.

1709221396258.png
They are very tiny, blink on their own, and don’t have the current limiting resistors which makes them more flexible. The only issue I can see is they are square, so making the holes for them will require a bit more than just drilling a 3mm hole. The 0805 package is 2mm x 1.25mm—very small.

You can also get non-blinking and various colors if needed.
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
Welcome to AAC.

You might consider these SMD (Surface Mount Device) blinking white LEDs with attached pig tails.

They are very tiny, blink on their own, and don’t have the current limiting resistors which makes them more flexible. The only issue I can see is they are square, so making the holes for them will require a bit more than just drilling a 3mm hole. The 0805 package is 2mm x 1.25mm—very small.

You can also get non-blinking and various colors if needed.
Those are great. But the rhythmic blinking is too fast and paced, so it would look very artificial. I'm not sure, but wouldn't they also all blink on and off at the same time if multiple were hooked up in parallel or series?

Even if those wouldn't work for me (size and shape don't matter, it's more of an illusion of fireflies than actual visible bugs), I super appreciate the share because they include a video that shows how to wire them up in multiple configurations, as well as if you want to use a wireless remote. So thanks!
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
There may be a feature that prevents new members from editing posts after a certain time. I know all members are restricted from editing private messages after about 10 minutes.

I assumed that there was a resistor, or other circuitry, to limit current because there are no LEDs that have a forward voltage of 12V and can tolerate any voltage variation without that.
The LEDs you referenced have 2 wires; a positive (anode) and negative (cathode). You have to get the polarity right or they won't turn on.

You wire all of anodes together and all of the cathodes together. The anodes go to the positive terminal of your battery pack and the cathodes go to the negative.

If you have a switch, you put the switch between the battery and the anodes. You can do it the other way, but the way I mentioned is the usual way.
You'll need 8 AA batteries to get 12V.
No problem. People of all levels frequent AAC and no one was born knowing anything about electronics.
Holy cow, that was fantastic. Thanks so much for spelling it all out. I could completely understand that.

8 AA batteries?!?! Yeah, I don't think these lights would work after all then. This is a really small project, and there wouldn't even be room for that much battery power.

Really, what I was hoping to find was simply a consumer-friendly battery operated string of "fairy lights" that twinkle or flash. But all I can find are ones that ALL blink on and off at the same time, or ones with multiple modes, none of which suit the project. I thought this would be pretty simple.

Best case scenario: Of the 17 lights, just the one on the bottom would need to be a steady 3mm white (it backlights the display). The rest would need to blink on, stay on for a couple seconds, blink off, all randomly, not in unison. Also acceptable would be non-unison twinkling, flashing (not too quickly), or flickering.

I'll keep searching to see if I can find something else. But in the meantime, if anyone has any suggestions, I'd be grateful.
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
I'm browsing the Evan Designs website. So far I've come across some "almost what I want." But some of the prices are prohibitive.

This is almost what I'm looking for. Nearly perfect, but if I understand their pricing, I'm looking at over $30. I honestly thought I'd find something like this pre-made for maybe miniature Christmas trees, running around $10 on Amazon. But all I'm finding similar are non-flashing, or everything flashes too fast or in unison, etc.

If I find something I think would be perfect, I'll run it by here, see if I understand what I need, and if anyone might have an idea how to do it cheaper.
 

dl324

Joined Mar 30, 2015
16,896
if anyone has any suggestions, I'd be grateful.
If you use 18650 Li-ion batteries, you'd only need 3 and could have more runtime. You can do tests to see how low of a voltage you can use. If you get sufficient brightness at 7.5-8V, you could use 2 18650's.

The batteries are 4.2V when fully charged, but drop to around 2.5V when fully discharged. Some choose to stop at above 3V to avoid overdischarging the batteries.

If you want a smaller volume for the batteries, you coud consider smaller form factor Li-ion batteries. I've used 16340 batteries to replace 3 AAA batteries.
 

dl324

Joined Mar 30, 2015
16,896
Here are the relative sizes of the batteries I mentioned. The 18650 and 16340 are fakes, but the size is correct.
li-ion-batterySizes.jpg
If you can get sufficient brightness at 7-7.5V, you could use a "9V" Li-ion battery. I have some EBL (8.4V) rated at 600mAh that would give you a couple hours of runtime.
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
OOOOOH! I may have had the answer sitting - quite literally - in front of me this entire time.

I'm linking to a video I made of the lighting fixture that was inside a decoration I've had for years, designed to actually look like you had fireflies in a (heavily frosted) Mason jar. This is exactly the effect I'm going for. I happen to have some green LEDs I bought when I made a light-up necklace version of Doctor Strange's Eye of Agamotto (ok, so I've dabbled once or twice in things like this before, I still hardly know what I'm doing). So in the video, you see me touch one to the soldering points on the circuit board where the top LED is located. It works! So here's what I'm thinking.

I'm wondering if I can take this apart, hook the circuit board up to a battery pack, take off the LEDs that are already on there, and connect 2-3 of these tiny LEDs to each point of attachment where an LED currently is using wires. I would have to connect the single LED separately for the bottom that doesn't have to blink. Illustration:
Firefly-Light.jpg
1) I know the LEDs have poles. So I know they'll have to be attached appropriately. The illustration was just made up quickly. I even forgot to add 2 more LED's for the total 16 I'd need
2) The LEDs I have state "Rated Voltage 3.0-3.2v" on the package.
3) As it is now, one AA battery supplies the power. I have those battery holders I mentioned, which can hold 1, 2, 3 or 4 AA batteries, so hopefully one of them would be enough?

I can take the base apart the rest of the way if you'd need to see the entire thing.

What do you think? If this would work, would I need to do something different with the single, non-glowing bulb to connect it to the same battery pack? Would it need a capacitor or anything?
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
Note on above - I meant to say resistor, not capacitor. But I realized my mistake too late to be able to edit the post.

Also, the yellow/green diodes I'd use are actually 2.0 - 2.2v
1709299823527.png
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
UGH. I keep researching and finding more information but too late to go back and change what I've posted before.

I'm learning that the amount of battery power needed for what I suggested above is WAAY more than the project allows.

So I'm trying to find out if my suggestion of using the fixture above would still work, but with rice light strings instead of individual diodes. The original kit called for those types of lights, and the amount of battery power to light all of them plus the single 5mm diode was just 3 button batteries.

Sorry. I feel like the entire thread should be deleted and started from scratch. I feel like I'm coming off as a dingbat. Just know that I'm still trying to research this on my own, and not just hoping to be spoonfed information. I'm trying to use online calculators, etc.
 

Ya’akov

Joined Jan 27, 2019
9,098
UGH. I keep researching and finding more information but too late to go back and change what I've posted before.

I'm learning that the amount of battery power needed for what I suggested above is WAAY more than the project allows.

So I'm trying to find out if my suggestion of using the fixture above would still work, but with rice light strings instead of individual diodes. The original kit called for those types of lights, and the amount of battery power to light all of them plus the single 5mm diode was just 3 button batteries.

Sorry. I feel like the entire thread should be deleted and started from scratch. I feel like I'm coming off as a dingbat. Just know that I'm still trying to research this on my own, and not just hoping to be spoonfed information. I'm trying to use online calculators, etc.
The specifications for LEDs provide numbers for current at their rated brightness. It is very likely that you do not need anything near that. It would be best to buy candidates and empirically test how much current they draw at the brightness you want.
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
The specifications for LEDs provide numbers for current at their rated brightness. It is very likely that you do not need anything near that. It would be best to buy candidates and empirically test how much current they draw at the brightness you want.
Thanks for that clarification. MUCH appreciated.

I purchased some rice light strands in the color I want. My plan is to disconnect the individual diodes on that fixture, and re-solder but with small strands of rice lights. There are 6 connection points on that fixture, and I need a total of 16 rice lights, so each connection point will only have to have 2-3 lights per string. Before I solder anything, I'll just twist them on the connections and make sure they work. I still need to disassemble the fixture first though to be sure i can adapt it to hook up to a battery pack, and then check the brightness as you mentioned. Also to make sure nothing is overheating.

If you would be so kind however, there is the single 3v LED I will need to hook up directly to the battery pack, so it will not pulse like the rest, but instead glow steady. I am thinking I will need to add a resistor, but 1) I'm not positive I will have to and 2) I've tried and tried to make heads or tails of online calculators to see what size resistor I would need, but just not understanding the info I need as far as volts or amps, etc. I'm imagining I will need anywhere from 1-4 AA batteries to run the whole thing (yet to test). So if there's any way you can indulge me and let me know what size resistor I'd need, I'd be very grateful.
 

Ya’akov

Joined Jan 27, 2019
9,098
Thanks for that clarification. MUCH appreciated.

I purchased some rice light strands in the color I want. My plan is to disconnect the individual diodes on that fixture, and re-solder but with small strands of rice lights. There are 6 connection points on that fixture, and I need a total of 16 rice lights, so each connection point will only have to have 2-3 lights per string. Before I solder anything, I'll just twist them on the connections and make sure they work. I still need to disassemble the fixture first though to be sure i can adapt it to hook up to a battery pack, and then check the brightness as you mentioned. Also to make sure nothing is overheating.

If you would be so kind however, there is the single 3v LED I will need to hook up directly to the battery pack, so it will not pulse like the rest, but instead glow steady. I am thinking I will need to add a resistor, but 1) I'm not positive I will have to and 2) I've tried and tried to make heads or tails of online calculators to see what size resistor I would need, but just not understanding the info I need as far as volts or amps, etc. I'm imagining I will need anywhere from 1-4 AA batteries to run the whole thing (yet to test). So if there's any way you can indulge me and let me know what size resistor I'd need, I'd be very grateful.
The resistor is to limit current. So, the information you need is the \(V_{FORWARD}\) of the LED (i.e. what voltage will light the LED), the \(I_{FORWARD}\) of the LED (i.e. how much current you light it to the level you want) and the \(V_{SUPPLY}\) (i.e.: the voltage of the power source).

The best way to work out the values is with a variable power supply that has a constant current capability. Setting the supply to any voltage and adjusting the current until the LED is bright enough tells you the current you need.

Failing that, you can use a brute force empirical method. Start with a resistor relatively high value resistor (e.g.: 2KΩ) and reduce the resistance in steps until it looks the way you want. You can get a resistor assortment quite cheaply—buy at least ¼W resistors.
 

Thread Starter

FierceCritter

Joined Feb 28, 2024
10
The resistor is to limit current. So, the information you need is the \(V_{FORWARD}\) of the LED (i.e. what voltage will light the LED), the \(I_{FORWARD}\) of the LED (i.e. how much current you light it to the level you want) and the \(V_{SUPPLY}\) (i.e.: the voltage of the power source).

The best way to work out the values is with a variable power supply that has a constant current capability. Setting the supply to any voltage and adjusting the current until the LED is bright enough tells you the current you need.

Failing that, you can use a brute force empirical method. Start with a resistor relatively high value resistor (e.g.: 2KΩ) and reduce the resistance in steps until it looks the way you want. You can get a resistor assortment quite cheaply—buy at least ¼W resistors.
Thanks again.

I'm picking up this kit. I'm going to follow your "brute force" recommendation. And start with a 1AA power pack and move up from there if need be.

This will also help me with other projects I'm sure to take on at some point. I tinker a lot with prefab kits or just ideas that pop into my head. I'm an autistic perfectionist who can't leave well enough alone if I think I can improve upon what I'm given. It can just be hard for me to wade through the kinds of numbers involved in things like this.

Can't express enough how much I appreciate all the very non-judgemental help here. I'll be sure to share the results once the job is done.
 
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