May 5, 2008 | Link This | Email this | Comments (1)

Don't feel bad about being confused by "medium voltage drives" terminology. It’s a confusing because it sounds like a technical term, but really it’s marketing driven. Actually, there are two terms that can be confusing to anyone new to the field of automated control of electric motors.

Let's start with the word "drive." Also sometimes called an “invertor,” a drive is essentially a power amplifier that puts out the electric power needed by an electric motor based on the torque and/or speed called for by the controller, which is a digital computer tasked with overall system control. As the industry has shifted in favor of variable-speed drives, the role of the drive has become more important.

Variable-speed motor/drive combinations use a synchronous ac motor with an encoder built in. The encoder signals the motor...Read More
Industries: Machine Control

April 28, 2008 | Link This | Email this | Comments (0)

This question relates to comments I made in an article that appeared in the March issue of Control Engineering entitled, “The culinary art of mechatronics.” In that article, I described the (so far) four generations of programming language, which are roughly:
1GL — machine code (ones and zeros)
2GL — assembly code (such as microprocessor op codes)
3GL — human-readable programming languages (Fortran, C, C++)
4GL — frameworks (Eclipse, Microsoft Visual Studio, National Instruments ...Read More
Industries: Information Control

April 21, 2008 | Link This | Email this | Comments (0)

We are indebted to Bill McGovern, national sales manager for Dataforth Corporation for this detailed history.

The birth of battery technology is credited to the Italian physicist Luigi Galvani who, in 1780, discovered that a frog’s leg would “twitch” when brass hooks attached to the muscle were touched to an iron plate. He named this phenomenon “animal electricity”.

Later in 1800, the Italian physicist Alessandro Volta capitalized on Galvani’s frog experiment by inv...Read More

April 14, 2008 | Link This | Email this | Comments (0)

Off the top of my head, I can think of 3 non-volatile random access memory (NVRAM) technologies in current use. I’m here defining NVRAM as a bitwise readable, writeable, and erasable memory technology for typical general purpose computers. In NVRAM devices, each bit has its own memory address, and can be part of the computer’s addressable memory along with the volatile static and dynamic RAM (SRAM and DRAM) chips shipped with the computer.

Electrically erasable programmable read only memory (EEPROM) is not NVRAM because it can only be read by a computer. It takes a special device, called a programmer, to erase or write to EEPROMs.

While computers can write directly to hard magnetic discs (also called Winchester drives or hard drives) ...Read More
Industries: Information Control

April 7, 2008 | Link This | Email this | Comments (0)

Flash memory cells individually resemble metal-oxide-semiconductor field effect transistors (MOSFETs) with an extra electrode. N-channel MOSFETs consist of two highly doped N-type silicon spots (source and drain) in a lightly doped P-type substrate connected to ground. Electrical connections are made to these spots, and a thin non-conducting dielectric layer covers all. A metal or other ...Read More

Industries: Information Control