Seven Decade Programmable Resistor


[Gerry Sweeney] was tired of messing around with resistors while prototyping his projects, so he decided he wanted a resistor decade box. The problem is they are typically big and rather expensive ($100+). Unhappy with the selection available for purchase, he decided to design his own.

In the accompanying video, he shows off his first attempt after being inspired by a past post we covered that used a combination of resistors and thumbwheel decimal switches. He modified the design a bit and used surface mount resistors instead, which made for a fairly compact and convenient seven decade resistor box. But he still wasn’t happy with it.

He decided to design his own PCB instead. The simple design utilizes surface mount resistors to conserve space, and jumpers to select the resistance. No bulky switches get in the way and it’s fairly cheap to produce.

Check out the great video explanation of the project after the break. He also shows off the insides of a commercial resistor decade box!

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