I’ve been an electronics hobbyist for many years, so I’ve used and even built my share of resistance decade boxes. Each one consisted of rotary switches with labels identifying a different power of 10 for each switch. You “dialed up” the desired resistance by turning the appropriate knobs to add up to the target resistance value.

Well, I’m also a computer geek, so I got the crazy idea to build a decade box using DIP switches (instead of rotary switches) and binary values (instead of decimal values). Each switch represents a power of 2 and the resulting resistance equals the combined value of the “ON” switches.

Since binary DIP switches are more difficult to read on site than rotary switches, I decided to include two sets of binding posts; one set to attach to an ohmmeter (to verify the selected resistance value) and one set to put the resistance in-circuit. A **DPDT** switch lets you toggle between them. Also, since the combined analog resistor values tend to vary from the perfect digital values you want, I added a 25 ohm POT for fine tuning.

This project uses two 8-channel DIP switches, which provide the following binary values: **1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1,024, 2,048, 4,096, 8,192, 16,384,** and** 32,768.** With it, you can combine switches to create any value between 0 and **65,535** ohms.

As is customary with binary numbers, I started with with the least significant digit (lowest ohm value) on the rightmost switch and increased in power-of-two increments to the maximum value on the left.

Well, I’m also a computer geek, so I got the crazy idea to build a decade box using DIP switches (instead of rotary switches) and binary values (instead of decimal values). Each switch represents a power of 2 and the resulting resistance equals the combined value of the “ON” switches.

**Read More: Binary Resistance Decade Box**