Evening, Okay, I got an EVE Hypo from a while back and its lit with an LED connected to 3 1.5v button cells. I want to hook this up to USB as I hate searching for button cells at the local shop and I can just have it on with the PC then. The total voltage then is 4.5v but the USB is 5v, I did a quick test and it seemed to work fine but I'm worried about two things as my previous electronics work has been that of 60% guessing and 40% research. So, will this bit of wiring either A) Blow the LED in a horrible manner or B) Blow up my PC which I can't overly afford to replace? Ta for any advice.
I reckon the worst it would do it blow the LED, done that a few too many times at uni... :S Any chance of placing a resistor in there?
You'll be absolutely fine mate. 0.5V extra might kill a cpu, but leds will survive. I've run 1.8V leds (standard red led) on 3v before. If you are paranoid, get yourself a 27 ohm resistor from Maplin or similar, and put it in series with the led. I highly doubt you'll need this.
Not the LED I'm overly worried about, its my computer that's the concern, by the sounds of it ethers no issue, right?
I'm guessing this led is hooked up to 3 x 1.5v cells with a resistor? As long as you reuse this resistor when hooking up to the usb 5v, then it will only be getting ~10% extra current - TL;DR: everything would be fine. But what the hell is a EVE Hypo They look like some sort of DIY tattoo machine... so are you trying to run the whole thing from usb instead of batteries? Considering it ran on button cells the current usage should be low... but it wouldn't hurt to check the specs just in case.
Haha mv, it's a Bioshock game prop, EVE is an injection you give yourself in the game to allow genetic mutation. The "EVE Hypo" he's talking is a collectible syringe prop, like an action figure Running a 4.5v LED on 5v USB? No problem whatsoever. Post pics when you're done!
Unbelievable, what will they think of next I won't mention how games aren't just creating serial killers, but drug addicts aswell
did you give it a test? I want to do the same thing with the NECA isaac Clarke figure I have but also worried about it blowing the LEDs or melting the fig. it also runs off 3 1.5v button cells (GP189)
Same for you, everything should be fine The leds will run nice and brightly, but safely, very similar to having brand new batteries installed: new 1.5v batteries are like 1.6-1.7v each!
Would love to see some pics of the completed mod though. Would adding another LED into the mix make any difference?
If you add another 1.5v LED in series it would reach 6v and supplying it with 5v should work but the LED's would be dimmer than using 3x1.5v LED's on a 5v supply. You would probably notice the difference but whether it matters to you is a question of taste
Considering the LEDs in the Isaac figure are white they'd be 3.2-3.5v so adding another in series would be a bad idea. The 100 ohm ish resistor you probably have in there will be fine when the supply is 5.0v rather than 4.5v.
As the guys have said, just putting in another led in series will cause them all to not be receiving much power, unless you wire them in parrallel and add a resistor.... Try a few combo's out with this: http://led.linear1.org/led.wiz
ok...did the mod, plugged it in ... GREAT! then a EYE POPPING 2 mins later.... DEAD! took the Issac figure appart and yup, both LEDs blown so need to replace them. but what can i do then to make it work
You didn't add a second LED without adding a resistor did you? If you tell us the voltage and current specifications or give us a link for your leds, then we can tell you what resistor to use... assuming you're actually getting 5v...
i didnt add a thing, I just gave it power... I will take a pick of what it looks like inside tonight and post it up.
You must have bypassed/shorted the original resistor, since both LED's blew I'm expecting to see leds with a little black spec inside them... if they are cracked then you were probably giving them at least 12v
