I’m needing to build a simple circuit that will allow me to switch a few (always on) bipolar LEDs between the two colors. The trick is, the switching needs to happen when a pair of metallic surfaces come into contact with each other, and there’s no room for a traditional relay or beefy batteries to be stashed. I’m building a few pair of futuristic handcuffs, and will be printing the bodies with a small void in which to cram the goodies.
So, the kind staff at Tanner helped me collect all of the necessary bits and pieces but I’m lost without a diagram.
Here’s my parts list for each:
2 bipolar LEDs (common cathode)
2 TL92 NPN transistors
2 1K ohm resistors
Optional: 2 hall effect sensors. Since one of the metal surfaces is a small neo magnet, it was suggested that a Hall effect sensor might be a good choice if the magnet can trigger it when contacting the other metal surface. I do not know how viable this is, considering the tight quarters I have to work within.
Battery voltage TBD. I have to use a button battery with solder tabs and have not purchased yet. I will need to know if 3V is enough or if I will need to run a pair in series.
Any takers?
David Jeter
DB Cinematic
Dallas Prop Shop
(469)286-6418