The most common way to program early PLCs was using so-called ladder logic programming. Basically, a ladder logic diagram was a graphical way of representing the functions in a typical PLC and the control actions it would have to take. For instance, lines on a ladder logic diagram could include opening or closing a switch, […]
FAQs + basics
Six FAQs about bearings and choosing between oil and grease
Rotary bearings consist of smooth rollers or metal balls and inner and outer surfaces (races) against which the rollers or balls travel. These rollers or balls carry load carrier and let axes spin freely. Bearings typically encounter radial and axial load. Radial loads are perpendicular to the shaft, and axial loads occur parallel to the […]
FAQ: What are other options for nanopositioning besides piezo actuators?
Nanopositioning—positioning on the scale of one-billionth of a meter—is a common requirement in semiconductor and medical applications, such as metrology, scanning, dispensing, and pumping. But consistently achieving nanometer-level resolution is beyond the scope of most devices that use mechanical rolling or recirculating elements. Case in point: the most common solution for nanopositioning applications is the piezo motor […]
15,000 metric gears – shipped factory direct
With the largest selection of stock metric gears, KHK USA is now able to meet the needs of industrial automation designs with off-the-shelf gears with the fastest of lead times. KHK USA based in Mineola NY, stocks approximately 4,500 skus in the New York warehouse for same day warehouse shipping and can now deliver, within […]
EASY Product Finder delivers intuitive search tool to specify Lenze drive solutions
A global leader and manufacturer of electrical and mechanical drives, motion control and automation technologies, Lenze announces the launch of the online EASY Product Finder. The easy-to-navigate and intuitive EASY Product Finder empowers machine designers and engineers to explore and specify Lenze engineered power drive, automation and motion control solutions. The new online EASY Product […]
FAQ: Are PACs just for process control or do they work for discrete plant functions?
By Steve Meyer || Programmable automation controllers (PACs) are (by design) a superset of PLCs. Everything that a PLC can do, a PAC can do. Some control tasks done by PACs are possible to do with a PLC but require expensive add-on modules. Conversely, the reliability and ruggedness so common in the physical builds of PLCs is […]
Lenz’s Law and Back EMF
Lenz’s law and back EMF work hand-in-hand. In electric motor operation, as the armature rotates inside the magnetic field, a voltage is produced. This voltage is commonly referred to as back EMF (electromotive force), since it acts against the voltage driving the motor. Laws of electromagnetism One of the fundamental laws governing electric motor operation is […]
FAQ: How to calculate motor temperature (worst-case) under required load?
Edited by Zak Khan || Stepper motors like other motors deliver different levels of performance at different temperatures. In fact, most stepper motors are designed to operate at relatively high temperature without issue — even to 90° C in some cases. However, undersized motors are at risk of excessive heat (not to mention sluggish acceleration if […]
FAQ: How do I pick torque margin to prevent stepper motor stalls?
Edited by Zak Khan || Torque margin is the amount of extra torque capacity a stepper motor has to ensure successful operation without stepper motor stalls. A sufficient torque margin is critical when a motion design incorporates stepper motors for motion, as in many cases there’s no correction of motion if the motor is temporarily overloaded. Read […]
FAQ: Where do PLCs operate?
Perhaps a better question would be where don’t PLCs operate? (or where PLCs aren’t used?) That may turn out to be a much shorter list. Briefly, a PLC (or programmable logic controller) is a stand-alone controller that users program to perform a sequence of specific tasks. The structure of a basic PLC program involves a […]