USB controlled mini lava lamps

Step 3 Poor man's usb plug

I did not want to destroy the USB plugs on the lava lamps so that they could be used separately, and so that the USB lava lamp controller was modular (other devices could be used switched on and off instead of the lamps). If you disassembled an apple keyboard in the last step you would have have two female USB-A jacks that you can use, and so can skip this step. You could also purchase the female USB-A jacks from mouser or salvage ones from a spare USB hub. I chose however to go with a cheap and simple option - a simple USB jack made from some striped wire wrap (any thin wire would suffice), a bit of perfboard, and some paper and transparency film for insulation. Simply cut a bit of perfboard to go INSIDE the USB plugs, add wire through the holes so that inserting the plug will not pull them out and will allow them to contact the +5V and ground connectors in the plug (see the pinouts on the "Make circuit" step for which connection is which). Then cut some transparency film to cover one side of the board so the perfboard wire will not short out against the metal body of the plug. Jam this insulated board into the USB plug, and confirm with your multimeter that the wires make a good contact and are not shorting. These are how the USB lava lamps are connected to the circuit. For this project, make two of these poor man's plugs head-to-head on the same bit of perfboard (see the image). During the assembly step, you will see how the case holds both of the USB plugs on this connector.

Comments

[John Whitlock]

I didn't have much luck with the poor-man's USB plug - too prone to becoming disconnected. What worked like a charm was a PCI-card USB plate, often included in motherboard kits. We had a firm USB connection, and the other end was a female plug for a motherboard, making it trivial to insert our own wires. Also, I'm not sure an apple keyboard is a good bet - my current keyboard just has one LED, for the caps lock button, and this project requires at least two.

[jamesh]

I'm sorry the poor man's plug didn't work for you - perhaps my perfboard was just the right thickness so that when I threaded the wire-wrap wire through the holes and added label tape on the other side it was just the right size to stay jammed in the USB plug. The PCI-card USB plate is a great idea for salvaging female USB plugs. I'm not sure about the apple keyboards, I think they have changed quite a bit over the past few versions. Thanks for the suggestions, and I hope you are enjoying the USB controller.