Click on the schematic (and all other pictures) to enlarge it. Sorry for the hand drawn schematic Depending on the resistance of the photo-cell that is used the 100K ohm resistor may need to be larger or smaller. If the resistance is not correct the circuit may not function properly. For example if it is light it may stay on or if it is dark if may stay off. To find the best value you could use a potentiometer to vary the resistance until the best value is found. Elmetal had a great idea to add an On/Off/Auto switch to the design, here is a schematic to do that.
All of the parts found their way onto the breadboard for some testing to make sure the design works before soldering it together.
From hackaday comes another Bawls light. This time though it uses a photocell to automaticly turn on when it gets dark.
“Ok get your mind out of the gutter. I am talking about the beautiful blue glass bottle that the Bawls soft drink comes in. I …
Alan shows you how to make a LED lamp from …”the beautiful blue glass bottle that the Bawls soft drink comes in. I tried one the other day and thought the glass bottle could be used for something interesting….
Nice project. I don’t have any Bawls laying around but I am thinking about making one from a green plastic bottle. Thanks for a great project! By the way the song ROCKS. I am downloading it right now I think it will be a permanent fixture on my IPod!!!
Hi Arthur (#17) you could do it with 4.5 Volts (3 AA batteries) You would need to change the two resistor values though. The 470 ohm resistor could be replaced with a 33 or a 44 ohm resistor. The 100K ohm resistor would take a bit of experimenting to find the optimal value though.
Hey guys, I wanna do this but I want it plugged in to the wall, and also I want a button with 3 settings, AUTO, OFF and ON. How would I come about that. so that in auto, it will turn the lamp on at night and you know the on would override the sensor and so on. how would I do this? email me at email@example.com please this is a genius idea having the bawls as a lamp. any help would be appreciaed… thanks guys!
What you would need is a single pole, double throw (center off) switch.
The center will be off. On the switch connect the 9 Volt positive wire to the common terminal (center).
Then to do the auto and on mode you will need a resistor. Connect one end of the 1K resistor to the transistor base and the other side of the 1K resistor to one of the empty switch terminals. Then connect the last empty switch terminal to where 9 Volts was connected in the original circuit (top of 100K and 470K resistors).
As far as powering it from the wall look for a wall plug that is rated at 9 Volts DC, with a current at least 50mA (not sure you could find one smaller but just in case). This would allow you to use the same values in the schematic. However you could use other power supplies with different voltages by adjusting the resistor values.
Kick ass idea. Felipe has a good enhancement though, I think making a hole near the bottom of the bottle and have a cord running up the inside of the bottle to the electronics and LED at the top would work great. Not sure where the switch would go. I guess there might be room for it on the cap beside the photocell if they are positioned well. Thanks for providing the new schematic for the switch, it rocks!
What you have to do is switch 2 wires around. Keep the photocell and 100K resistor connected together at the common central point (the way they are now), and swap where their other leads go. This will allow it to work in reverse to what it is doing for you now.
Many of the parts come in 5 packs etc. I didn’t include the parts that are NOT included in the project in my price estimate. If you shop at a place other than Radio Shack you could do it a bit cheaper, but Radio Shacks are everywhere and convenient for most people.
The out of pocket cost to build this project is NOT $2-3. You CANNOT purchase each of those items individually. The parts list that you personally provided, when placed in a shopping cart and purchased is $8.39+shipping. In the real world “spare parts” are factored in to the total cost of a project.
Also, hey #44 “Total: $2.60″ , Oh, so a 9v battery costs .40 cents eh? Where do you shop?
Maybe you should indicate as such in the build list. This all is absolutely misleading.
Well to each their own, I am sorry that you seem to have such a strong opinion on the way I calculate project costs. For example if I am building a project that needs 10 resistors and I purchase a pack of 100. I still have 90 in my parts bin so I personally don’t factor the unused parts into the build price. If I did that then this project might have cost me $50 since I have lots of spare parts Batteries are not usually included in project costs since batteries will be an ongoing expense. Plus if you are so worried about the price go to a dollar store and get the 2 pack of 9 Volt batteries for a buck. I am also not considering the cost of the bottle in this, if you don’t have a pop bottle kicking around you will have to shell out some more money for some pop. If you want to think of the project as a build 5 for $15 dollars maybe that is the way to think about it
Hi Len (51),
I don’t have detailed pictures of the construction other than what I have posted already. If there are some other people who would like it done I will post it soon. If not give me a while and I will get around to it. I am happy that you want to give it a try as your first step in electronics though, that is the main purpose of this site and http://www.alan-parekh.com .
Hi, I have a question with the blue bawls light. I dont know where to start. After I drill the 3 holes in the cap for the photo cell. Whats next I cant figure it out from the pictures or the instructions. Help me please
Alan this is a awsome build. I just got a bottle of Bawls never had it before or even seen it. I found the bottle from there web site I had to drive a couple miles for it but it was worth it. I drank it up it was the best energy drink I had and tasted good. I ordered some parts from you. Cant wait till I get them too start building. I see you have a resistor chart on your site too find out what size you need the only thing I want too know is when you have a transistor how do you know what you need for resistors? They only show one resistor being used in the diagram I want to know how you figured what you needed for resistors for future builds. Thanx
There are many ways to build it as long as it is electrically the same as the schematic. I have built another one taking many pictures along the way and posted it on the Instructables, have a look. If you have any other questions please ask
Yeah Bawls is great! The transistor is simply acting as a switch in this case. The collector (C) emitter (E) voltage drop is negligible so you can just ignore it for basic calculations. You will notice that the current is lower than the MAX for these LEDs. This is because the unit is running from batteries and the way it is set gives the best light output/run time balance.
This is exactly what I am looking for, but for a different purpose. I work a local Ren Faire, and I end up getting to my car after dark, in about a 60 acre unlit parking lot. My car is dark, the lot is dark, and the background is dark… I want to have a battery powered device in a window or two that blinks and helps me find the car. The photocell will help it not run during the day!
I know what you mean about the guy harping on about the price. I guess someone has to over analyze everything. I am surprised he didn’t factor gas money into his calculation since it isn’t free to get to the store and back.
I’m having two problems, One is that I cannot read the resistors (the colours) so I cannot figure out what resistor I have to use and I cannot figure out the transistor either because mine is labelled diferently. Mine’s labelled ABC while yours is labelled BCE? Could you help me?
On page 2 there are links for the two resistors and the transistor. Click on these and look at the picture of them. The picture is the actual resistor color code and transistor pin out. Transistors all have three pins a base (B), collector (C) and emitter (E). Most small transistors have the same in out, or post the model of transistor and I will look it up for you.
Hi, I have a Question. When you start to solder the NPN Transistor , I put to much heat to it. And When I fix the whole light fixture. the light comes on, but it comes on very dull. Could it be that the Tranisitor is burnt out? Please Help me.
Does your photocell increase in resistance in the dark? A standard photocell does. Here is some more information about their basic operation, test yours and see if it is operating correctly. http://en.wikipedia.org/wiki/Photoresistor
These look great and make great garden lights for parties etc.
except that over in the UK we have no bawls so Sherry bottles will have to do!!
Do you know where can I down load the .mp3 for my pod??
Today, I went out to buy some parts to try and make this, but when I tried testing it, the light does not turn off no matter what, and it is VERY dim. Any ideas why? Here are some pictures of it assembled: http://robm.drunkencoders.com/led_project/
I’m trying to build the same thing and have run into a bit of a snag, but the light on mine doesn’t come on. I’ve verified that the battery, photo-cell and LED are good; not sure how to check a transistor, but I have tried two and they are brand new. Both are 2N4401s, just like yours. I have tried varying the resistors, but I am afraid to go too low because I don’t want to burn out any of my components.
From what I see the circuit looks correct. Keep everything the way it is and pull out the photo cell. If the light turns on you will need a different photo cell. The one required for this circuit is the most common type that goes towards an open (high resistance) when in darkness.
Thanks, but as it turns out, it was the last thing that I could have expected. It was the copper wire. I didn’t realise it, but that’s wire for winding electric motor coils, so it’s coated with a transparent insulator.
Well, it works now and looks nice. I have a blue vodka bottle filled with glass beads and an 1100mcd white LED, so it’s a soft light, good for a night light I think.
hey Alan…i must say it looks fantastic! but i was wondering, can the same concept be used to power any circuit? I mean using the photocell but ofcourse replacing the led part with the +V of a different circuit (maybe an led flashing sequence or something)?
I just built this circuit because its friggin awesome and I completed it and it WORKS! however, the “super bright” led is REALLY REALLY faint. I was wondering how the hell I can make it brighter? I tried changing the resistors to around 200ohms instead of 470, but that didnt do much, any ideas? (I also changed batteries, to no avail)
When it is on (as bright as it can go) meter the voltage from the transistor C to E. There should only be a small voltage there, if there is a large voltage there you might have to adjust the 100K ohm resistor to bias the transistor more.
Actually the light should turn on as the photo cell gets dark, as the photo cell gets dark the resistance should increase. Therefore by removing it from the circuit it should turn on as bright as it can. Meter the photo cell and see if the resistance changes when it is exposed to light and dark. It is the low resistance when in the light that turns off the transistor.
Fascinating! I do not know the bottle or the product but here in
Bristol UK – famous for hundreds of years for its ‘Bristol Blue’
Glass – I think I shall have to give it a go. I particularly like
the development of the idea of the batts’ being inside the bottle
through to an OS power source. I can just see them gracing the OS
table during the warm summer evening. (Not a grammatical mistake;
summer here was July 29th last year, at about two o’clock). BUT,
why not make a plain plinth for the bottle to stand on? The plinth
could hold all the gubbins with a simple jack plug connector
transferring power to the LED through the female part glued into
a hole drilled in the base of the bottle. Suspend the LED between
two rigid wires stretching half way up the bottle. Ok I haven’t
considered the photoelectric cell, it’s midnight, the creative
juices have dried up and I need my kip!
Thanks for a wonderful site
Whizz (with an ‘h’ not the other fellow)
Hey folks…I’ve designed a pcb for the Bawls light (original version) that holds the 470 ohm
resistor, a 100k trimmer (replaces the 100k resistor for variable sensitivity) and the 4N4401
transistor…it has external holes for a 9v supply, the photocell, and 2 leds (you can use one
led by just jumpering the 2nd terminal to complete the trace). The upshot of all this is that
the board itself is only .5″ x 1″ (1 sq. inch) and fits perfectly inside the bottle. Let me
know if you want the file, and I’ll send (e-mail) it to you. It’s an Express PCB file (*.pcb);
just for the record.
I have taken and covered most of the LED with heat shrink tubing to hide part of the light source. In some cases it looks better. I’ve been using this circuit to make lights for my young relatives and their friends. I have a huge one gallon Seagrams 7 Crown bottle this circuit works great for. Way back when I was a youngin I used to light it with a single 7 watt incandecent bulb. Now all my young nephews want my Seagrams bottle.
when i did this i think i messed up but i cant find when i have taken and put it back together many times and still when it is in the light it turns on and when its in the dark it turns off if you know what i did wrong please email me at firstname.lastname@example.org
use coated coil wire to power the device, the wire is very fine (think fishing line) and it also provides alot of resistance. With about 2 feet of it, i didn’t need a resistor on the led, although i am going to run another foot to be on the safe side.
Note: you can buy small rolls of coil wire from radio shack, or you can sometimes get some off of a transformer)
Alan, I have tried to build this with the switch to no avail. Either nothing works and the battery gets hot,
or the switch has basically no effect. I have drawn a diagram of my build, kind of a 3d schematic.
It is on pdf format. Can I email it to you so you can see if I am just WRONG? or making a simple error?
ok, i made one…theres one problem. the led i bought from radio shack blows, such a dim light. are there any
electronic stores i can purchase a bright led from besides radio shack? this light just isnt cutting it and i really dont
want to go through the trouble of ordering it off the internet.
this is really cool, this thread looks dead though.
but i need HELP!, im not very good with circuits, and i am having an extremely difficuld time calculating voltage drops and differences in currents and volts, im using a different LED, but i dont know what you are using to compare it to.
would it be possible to stick like 10 or more of these LEDs to the project? if so would it require a series or parallel circuit? i have no clue.
I just finished my project about LED lighting for holiday use. It is custom made and I did all the design by myself. I got some idea from this website http://www.lunaraccents.com and study from some other sources online.
sorry to bump this thread
but i built this light to the exact specifications, i have made 4 of them but none of them work they way they should.
the photocell dims the light in darkness and brightens it when light is introduced.
i’ve wired it every possible way i can and it still wont work.
im thinking i bought a bad batch of photocells…
and i’ve gone through a few transistors to make sure they weren’t ruined by the constant re-wiring.
Hey, I wanted to make one of these with the switch, like someone asked earlier (posts 33 & 34). However, the link posted in #34 is dead now. Can anyone help me out with a schematic for this variation of the project?
Your idea would probably work, I think your best bet to make the circuit work would be to simply feed the existing negative and positive of the circuit from the higher voltage made using the joule thief.
Has anyone made a bottle lamp using a plastic bottle? I got a very special collector’s bottle while I was overseas, and want to preserve it as a small night light or lamp. This glass bawls lamp (I love the bawls soft drink by the way) looks fantastic, but I’m worried that if I tried this with small plastic bottle, it might melt. Any suggestions? I’ve scoured the net and found nothing helpful. Thanks in advance!
[...] of toil got me the bowlful below. Phwew, talk about hard work. All worth it though, as I sip my BLUE BALLS -N- SAGE, and revel in the healthyness. blueberries are a diuretic, loaded with flavonoids and [...]
Hello Alan,thanx 4 the project,and 4 all the answers you gave-read them all
i came via hackaday,but i’m looking 4 a similar circuit in which a microphone is the ”switch”
as i’m not that good at …tronics
what i mean is that when a mike pics a sound it triggers the transistorwhich switches
on the led…
might need an opamp to amplify the signal?
if you could help me with the schematics,i’d …
Cool Bawls hack! I used to drink sooo much of those things when I worked at Office Depot’s corporate office that I had a cubicle built out of them(figuratively)…but hey, there was another hack that you did which was the ‘create your own embroidery machine”, but hacked gadgets took it down I think, because it’s no longer there. Do you still have it, and if so, could you repost it or email it to me? That would be awesome if you could! Thanks, and keep the hacks coming!!
[...] the LED is off. When the lights are off, the LED turns on, and lights up your case, lights, etc. Simple but oh so much fun. In this case, a Bawls Blue bottle was used as a lamp for this project. [...]
Hey, i have a 12V battery and 12V led panel. I was wondering if someone knows what transitor and what riesitors i would need to use for this setup? Im trying to set up my greenhouse so the light automatically comes on during night. Any help?
I’m trying to do this project, but the 9v battery won’t fit into the top of the bottle. I looked at your pictures, and my bottle is different than yours. It says 296 ml and 10 fl. oz. I can’t find any bottles like the ones in your pictures. Do you know of anywhere to get those style bottles from?
There are lots of different LDR devices, I think the ones that I used go to about 1M ohm when in complete darkness. If you got a 1M pot you could find the sweet spot for your needs. The base is usually the center pin but this is not always the case. If you flip the 100K resistor and LRD around that will change the way it reacts to light.
[...] September 22, 2009 · Leave a Comment Hello and greetings fellow bloggers and gamers. Tonight I’ll be posting a DYI Project on how to build a sensor sensative Gamer’s Light to spark up that avid gamer’s bedroom or apt. Here is the Video with a walk thru with commentary and all. Thank Hackedgadjets for this project please and show your support [...]
First off, I want to thank Alan for an awesome DIY project. This can also be done with anything, from empty juice bottles to wine or rum bottles. Now on to my suggestion.
“It is best to place it on something that is white or at least a light color. The LED is pointing straight down and a good reflective surface helps. I am thinking of cutting a small round white disc of cardboard and gluing it to the bottom.”
And a good thing could be a cd or dvd disc. I have a ton of those hanging around my closet because i refuse to throw them shiny things away. They are reflective enough to bounce off light very nicely. An empty cd or dvd case can also be a worthy container for your led lamp design. I loved the photocell usage. Had not seen one like this ever.
I am also relatively new to these things, could you comment on the transistor usage? What is it for!? My electronics course pretty much covered resistances, and how to combine them to get higher or lower ohms from them, but I never learned about these other parts.