Skip to main content

Binary Resistance Decade Box

I built this project in June of 2013 and posted it on Instructables





LINK TO PROJECThttps://www.instructables.com/id/Binary-Resistance-Decade-Box/


Binary Resistance Decade Box

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.

Comments

Popular posts from this blog

Project of the Month for May 2019

Project of the Month

This month's project is the ESP8266 Weather Station Kit by Ideaspark!
Why not buy one now and build it along with me? Here's a link via my Amazon Associates account. Purchase it here and help me support My Parts Chest website and App (available on Google Play and the Apple App Store).


ESP8266 Weather Station Kit with DHT11 Temperature Humidity BMP180 Atmosphetic Pressure BH1750FVI Light Sensor 0.96" OLED IIC YellowBlue Display for Arduino IDE IoT Starter(Guidance Document Included)
Price:$20.99

✔️The weather station uses the ESP8266-12E to obtain data from the Internet: time of a city, weather data and forecast information for the next 3 days, scrolling on the SSD1306 OLED Display; the device can switch to display data from any city in the world - maybe your relatives or friends live there✔️The device uses sensors DHT11, BMP180,BH1750FVI to collect temperature, humidity, Atmosphetic Pressure and light data. The weather station reads data indoor via sensor…

ESP8266 Weather Station

This was a fun and interesting project built from a kit by Ideaspark. It teaches you, not only how to push data to the web using an ESP8266, but also how to retrieve data from an API and parse the resulting JSON.

I built this project back in April-May of last year. I actually posted it as the Project of the Month. I got some good feedback from others who built it along with me.

As the name implies, the brains of the project is an ESP8266 microcontroller. The weather station senses local values for temperature, humidity, barometric pressure, and ambient light and uploads the data to ThingSpeak. At the same time, it also grabs weather data and 3 day forecast from the web by calling the OpenWeathermap API and outputs it on to small OLED display.

The kit includes all parts needed for the weather station:
ESP8266-12E Microcontroller w/ builtin WiFiDHT11 Humidity and Temperature sensorBMP180 Barometric Pressure sensorBH1750FVI Ambient Light sensorSSD1306 OLED DisplayUSB cableBreadboardCable…

Project of the Month for March 2019

Project of the Month

This month, I chose a robotic arm kit from MicroBotLabs. 

Why not buy one now and build it along with me? Here's a link via my Amazon Associates account. Purchase it here and help me support My Parts Chest website and App (available on Google Play and the Apple App Store).

ArmUno 2.0 MeArm and Arduino Compatible DIY Robot Arm Kit With MeCon Motion Control Software and Arduino Source Code Via Download Link
Price:$39.99

Robotic Arm Kit includes Servo motors, Structural pieces and all Fasteners needed for assembly Plus MeCon Software and Arduino Source Code Via Companion Web Site and Download Links.Windows PC Motion Control Software Allow you to Teach and Record Motion Paths for Automatic PlaybackMake your own desktop size 4-axis parallel-mechanism Mini Industrial Robotic Factory Arm!This kit features a Companion Web Site full of information resources and makes a great educational resource kit for robotics and micro controllers.Precision Laser Cut Parts Require only …