HAL9000
Kommentit
8 1 January 2022, 17:14
![](/profiles/img/61283-429-s.jpg)
Nicely done! I hope you don't fry that led. I don't see any resistors between it and the 9v battery, and that led is probably 3v. I'm still learning electronics so I'm not entirely sure, but a burnout would be unfortunate if everything is glued up tight. Hope not!
1 January 2022, 20:08
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Hi JD, I did some calculations on the current limits of LEDs. While I had to guess what the spec limits on this LED were, most of them have a voltage drop of about 2V, so with a 9 volt supply and a desired current of about 25mA (typical of these LEDs), I calculated the resistor to be ~280ohms. Thus I used a 300ohm resistor. The LED is noticeably dimmer (still plenty bright) but I'm sure a lot less stressed and likely to not burn out. Thanks for the thought. I'm surprised Mobius models didn't include a resistor in their pre-built electric circuit that comes in the kit.
24 January 2022, 05:03
Album info
I added a voice chip to allow HAL to talk at the push of a button