Fisherman82 Posted February 20, 2018 Share Posted February 20, 2018 Hello, Im building a simple cockpit and since I use a monitor and not VR I want to have a little kneeboard light inside it. If someone that is good at electronics reads this I could use a little help. I have found a LED booklight that would work pretty well that uses 2 serial connected cr2032 batteries. However I dont want to change the batteries all the time so I would like to convert so that I could connect it to a AC/DC-adaptor. Since the cr2032 batteries are 3V each I should need a adaptor that outputs 6V. I have found one that can output 6V and max 1000mA, Im thinking that this should work however Im not certain. The thing is, I know that normally the important thing when choosing a AC/DC adaptor is that it outputs the right voltage and the same or more amps than the device needs. However I have also read that with LEDs you normally need to limit the voltage AND the amps to not burn it. These two things dont mix in my head, do I need a resistor even though the adaptor outputs the same voltage as the two cr2032 batteries would? Or will the little light only take as many amps as it needs (Because it wont be even near 1000mA). Link to comment Share on other sites More sharing options...
McG Posted February 20, 2018 Share Posted February 20, 2018 This might work for you, a LED book light powered by USB from IKEA. http://www.ikea.com/gb/en/products/lighting/work-lamps/jansjö-led-usb-lamp-black-art-70291232/ Link to comment Share on other sites More sharing options...
Fisherman82 Posted February 20, 2018 Author Share Posted February 20, 2018 Thank you, I have thought about that one but I think the other one with the batteries looks better. Link to comment Share on other sites More sharing options...
frogger Posted February 21, 2018 Share Posted February 21, 2018 if your handy and have a spare usb cable i would touch the black and red wires to the contact points without the batteries in and see how bright it is on the 5 volts supplied. going slightly less volts should run it just it will be slightly less bright. i have done this with some battery operated colour bar lights that run on 4.5 volts , running them on 5 volts has not damaged them in the last 6 months they have been operating. Link to comment Share on other sites More sharing options...
hansangb Posted February 21, 2018 Share Posted February 21, 2018 You can also buy LED strips that you can plug into USB for power. If you have somewhere were the LED strip can be attached. This one, for example, has one off button built in. You can also buy powered USB hubs with its own power buttons if that's more convenient. https://www.amazon.com/gp/product/B01FJUMP6M/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 hsb HW Spec in Spoiler --- i7-10700K Direct-To-Die/OC'ed to 5.1GHz, MSI Z490 MB, 32GB DDR4 3200MHz, EVGA 2080 Ti FTW3, NVMe+SSD, Win 10 x64 Pro, MFG, Warthog, TM MFDs, Komodo Huey set, Rverbe G1 Link to comment Share on other sites More sharing options...
romeokilo Posted February 21, 2018 Share Posted February 21, 2018 Or will the little light only take as many amps as it needs That is correct. Your selected power supply (6V 1amp) will work. Sent from my SM-G950F using Tapatalk Link to comment Share on other sites More sharing options...
Fisherman82 Posted February 21, 2018 Author Share Posted February 21, 2018 Thank you guys for all the help, now I got some alternatives to choose from! Skickat från min D5503 via Tapatalk Link to comment Share on other sites More sharing options...
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