Looking to track direction of motion or want to squeeze a few extra counts out of your encoder? You’re going to want to know about quadrature. A quadrature encoder is an encoder that has two output channels, with one being offset by 90 electrical degrees, or one quarter of a cycle. With a single output channel, you can tell that something in the system is moving–but you can’t tell in...   Read More »

Have you ever been in the middle of counting something and lost your place? If you didn’t have a system or way of recalibrating where you are, you’re going to have to just start over from scratch. Turns out this can happen with encoders too. If you are designing a system where you can’t let that happen, you’re going to want to know what an Index is. An Index is a unique channel on an encoder...   Read More »

US Digital encoders may play a role in helping save lives during the coronavirus pandemic. Project Pitlane, a group of seven UK-based F1 teams working together to design and make ventilators, placed an order for several thousand E5 Optical Encoders in early April. The ventilator design uses electric motors to pump air into a patients lungs. Encoders are needed to help regulate the flow of...   Read More »

When ElectroCraft needed help validating encoder output for a customer, it turned to us for help and walked away with a completely customized software solution at no cost. The Quadrature to USB Adapter (QSB) is a low cost device designed for basic encoder testing when it is not practical to use an oscilloscope. A custom application developed by US Digital, helped motor maker...   Read More »

Here at US Digital, we’re always looking for ways to improve our existing processes and how we can use automation to enhance what our people can do. Sometimes a challenge with one particular product can lead to a solution that benefits our entire product line. After releasing our E4T and E8T miniature optical encoders, we decided to take a look at improving efficiency in our surface mount...   Read More »

What exactly is the difference between incremental and absolute encoders? Both can be used to measure distance, speed, acceleration and position of a mechanical system. The key difference is what happens if that system has a loss of power. After power cycling, incremental encoders are not going to be able to report exact position of the system until they find the index/home position – if they...   Read More »

Wondering what exactly an encoder is and what it does – or maybe just how to explain these things to someone outside of the motion control industry? In this post we’ll cover some of encoder basics so you can leave with a better understanding, or maybe just a clearer way of describing what an encoder is and what it does. Encoders come in a variety of configurations, but they all...   Read More »

In this world three things are certain: death, taxes–and electrical noise, to paraphrase Benjamin Franklin. Electrical noise happens. Period. It can wreak havoc by injecting false signals onto encoder lines, or by overwhelming real signals entirely. It’s often intermittent, which can make diagnosing and fixing it a nightmare. But if you use a few simple techniques you can drastically reduce...   Read More »

Where do encoders face their toughest operating conditions? One answer at the top of the list is in the petroleum industry, where encoders are used everywhere. In this post we’ll look at encoders in the oil industry, from beginning to end–the rough conditions encoders face on oil drilling rigs, how they keep oil flowing in transport pipelines, and the way they ensure accuracy at gasoline...   Read More »

If you need an encoder that can measure very small distances, which of the following is most important to you? High Accuracy? High Precision? High Resolution? All about the same? Here's a hint: in the everyday world, those terms might seem like they mean the same thing, but in the world of encoders, accuracy or precision won't help you solve this problem nearly as much as...   Read More »

How do you attach an encoder to a liquid? Encoders usually attach to a part of the system that moves—and in a pump, the part that moves is a liquid! How do you attach an encoder to that? In actual practice, you don't. Every pump has a mechanism that moves a fluid. You attach the encoder to that mechanism. If a motor drives the mechanism, for example, you can mount the encoder to the motor...   Read More »

When US Digital released the E4T Miniature Optical Kit Encoder it needed to update manufacturing procedures to better handle the miniaturized encoder disks. The company decided to use automation and built the delta robot system above. It speeds up manufacturing and frees staff to spend time on higher-level tasks. New Miniature Encoder Disks Caused Production Difficulties for...   Read More »

With some optical encoders you can literally see the resolution right on the encoder disk. Look at the disks above and notice how closely the lines are spaced. Encoder resolution is defined as the smallest distance that can be measured or observed. However, it can be used in three different ways within the same motion control system—this can lead to confusion. In this post,...   Read More »

So far in this blog we've written about encoders that are moved by something else. They're attached to a motor shaft, or a linear actuator, or conveyor belt. Their job is to report their position as they're moved by an external force; other than that, they're just along for the ride. Well, sometimes - the encoder is the ride! Sometimes the encoder moves first, and everything else reacts to...   Read More »

In an earlier post to this blog, we introduced Absolute Encoders. We illustrated the differences between absolute and incremental encoders, and showed that an absolute encoder can give a unique report for each different position on the encoder disk. But we didn't talk about what that report looks like. Looking back to incremental encoders for a moment, each part of their output waveform looks...   Read More »

In the motion control industry, accuracy is the difference between target position and actual position. For rotary encoders, we measure accuracy in degrees, arcminutes or arcseconds. 1 degree = 1/360th of a circle - used with low accuracy encoders arcminute = 1/60th of a degree - used with medium accuracy encoders arcsecond = 1/60th of an arcminute - used with high accuracy...   Read More »

In earlier posts to this blog, we introduced incremental encoders in Encoders 009 and continued that discussion in Encoders 011, where we talked about Quadrature and Index. In today's post, we'll introduce another major category of encoders: Absolute Encoders. Where Are We? In our posts on incremental encoders, we developed a simplified picture showing essential components: In...   Read More »

The surge in popularity of drones in recent years has been remarkable. Although sometimes we hear about them when they cause trouble—like flying too close to commercial aircraft—more frequently we hear about drones because of the interesting new ways they're being put to use. Drones are used in agriculture, to monitor crop growth and field conditions. Home inspectors for insurance...   Read More »

Our plan for these posts has been to focus on technical concepts in posts released on the 2nd Tuesday of the month and focus on real world applications in posts released on the 4th Tuesday of the month. We’ll continue that pattern with today’s post and discuss the exciting application of Encoders Used on Mobile Robots. Years ago, the world of science fiction promised us we would all...   Read More »

This post continues our discussion of the various classifications of encoders identified previously Form of Output One of the most common classifications used for encoders is whether their architecture is incremental or absolute in design. This refers to the type of output the encoder emits, or what information is being provided by the encoder. This post will begin our discussion of...   Read More »

What do an organ, a black widow spider, and a scale have in common? It has always been intriguing how companies came into existence. US Digital's founding is an exclamation to the saying - "necessity is the mother of invention". David Madore, the founder of US Digital, worked at the time as a design engineer for a medical ultrasound imaging company. The equipment had many knobs on the...   Read More »

We will continue in this post going through the various classification of encoders which were identified in our earlier post. Mechanical Configurations Mechanical configurations include differences based on whether the encoder comes with a shaft or will be installed onto an existing shaft. There are also different configurations based on the size of the motor, the required IP rating,...   Read More »

NASA doesn't just make spaceships! Who Made the First Optical Encoder? We have been researching the answer to that question for some time and although we have been able to gather some great information both from encoder manufacturers and my own research, at this point we do not have a definitive answer. When we initially tried searching for an answer, someone had answered the...   Read More »

Encoders Have Been Used in Space Exploration for Almost 70 Years In our March 12th post, we identified different ways by which encoders can be categorized. In that post we focused on the first category - type of movement which encoders are able to monitor. Today we will discuss the second category: sensing technology used in most encoders. Note: The descriptions and drawings in this post are...   Read More »