Hello, I'm a newbie on this forum. So first of all let me briefly introduce myself - i'm a ukrainian DIY hobbyist and while my main interest is audio (see my signature) I'd like to build a bit unusual UV flashlight.
From time to time I need UV flashlight. It should be very small, even smaller then usual keychain flashlight yet much more powerful then something like nitecore tube UV (this toy has usable range of 2 inches lol).
So I've decided to build a small uv flashlight without battery inside and use a smartphone as a power source. Please take a look what I've built:
And attached to smartphone:
Small animations to show what this flashlight is capable of:
What do you think about such idea and it's implementation?
why does it have a battery if it is powered from a phone? It could perhaps be made smaller without battery
which led do you use and how much current is it getting? If it is a 365nm led, the fluorescence performance will improve a lot if you add a UV-pass filter before the led (like a ZWB2 filter), that filters out any visible stray light.
personally I prefer a separate UV-light with a battery, I have built many UV-flashlights and the smaller 10440-powered ones run at 500mA and are not much larger than your device and handier in use I think. But you are right that what you made is much more powerful than the Nitecore Tube-UV bacause that uses a very low-power 5mm led
It doesn’t have battery. As I’ve said it is powered by smartphone. Let me explain what’s inside - it’s not so easy to drain current from Iphone or latest Android devices.It is processor inside that tell smartphones that Audio DAC is connected
Also inside is a copper heatsink
I use Optosupply leds and driver is set to drain 100 ma at 4V. It’s easy both for led and smartphones.
I know but I even like it has some amount of visible light. Helps to find things in complete darkness.
My is 35*40*7mm. I can make it smaller but IMHO it’s already small enough to be lost quickly
Also the main point - it’s attached to smarthpone and you can shoot photos and videos with it. With standalone flashlight it’s less convenient.
Thanks for the answers. 100mA is a nice current to keep the heat in control with just a small heatsink. I did not think about using it as a camera light, it is indeed a handy format for that use.
I still think that you have a nicer light with a ZWB2 filter. On ebay and aliexpress there are 10mm diameter/1mm thick ZWB2 filters for sale that you could be able to fit nicely.
Are you planning to sell these?, or is it a personal hobby project?
Yep, that’s the point. I’ve made this for my friend that is inspecting restaurants, hotels etc. With this small thing he can immediately send photo or video of what is happening in the kitchens, beds etc.
I know, but I’ve decided to have some amount of visible light on purpose to let smartphone cameras to catch more light.
Everything I build starts as my personal hobby project (see my signature) but If I produce something people like I can’t resist to earn some money
Brief explanation why everyone who want to keep his house clean need UV flashlight. Everything is recorded with smartphone\ smartphone with attached flashlight.
Guys, please look at video - main purpose is UV flashlight for smartphone With filter you won’t take more or less decent shots from smartphone camera.
And from my point of view fluorescence is visible in almost same way with or without ZWB2 filter.
No, it will not work this way. To start a production and sell them at a reasonable price I need orders for at least 250 pcs. I need to order PCBs, buy led at bulk prices (by the way one led cost about 5:money_mouth_face:, make a small injection mould for plastic case. This is a new device from scratch, not a mod of existing flashlight.
So I guess I’ll go to Kickstarter. If you think that I’m some sort of fraudster - check my previous Kickstarter project or website in my signature (especially reviews section)
In my experience (so not an opinion), the addition of a ZWB2 filter to 365nm light from any current UV led improves the fluorescence contrast enormously, allowing users to distinguish many fluorescence details that are completely invisible without the filter. Further, the stray light from a UV-led is a particularly poor source for background illumination, if a background illumination is desired, a second white led would give better quality plus there is the option to switch it off. Or the inbuild smartphone light could be used as secondary illumination. It does complicate the design of course.
This is all a suggestion from my side to improve the design, I do not mean to say that the current design is bad, I still think it is a nice gadget as it is now.
