David Herres
David Herres holds a New Hampshire Master Electrician’s license and has worked as an electrician in the northern part of that state for many years. He has focused on writing since 2006, having written for such magazines as ELEVATOR WORLD, Electrical Construction and Maintenance, Cabling Business, Electrical Business, Nuts and Volts, PV Magazine, Electrical Connection, Solar Connection, Solar Industry Magazine, Fine Homebuilding Magazine and Engineering News.
Waveforms, a Little Trig and Elevator Design and Repair
Appreciating and understanding waveforms as applicable to elevator work Value: 1 contact hour (0.1 CEU) This article is approved for Continuing Education by NAEC for CET® and CAT®. EW Continuing...
Digital Signals in Elevator Circuits
The ins and outs of mixed-signal equipment Value: 1 contact hour (0.1 CEU) This article is approved for Continuing Education by NAEC for CET® and CAT®. EW Continuing Education is...
Electrical Parameters
A review of the fundamentals and the subtle ways in which they interact Value: 1 contact hour (0.1 CEU) This article is approved for Continuing Education by NAEC for CET®...
Latest Instrumentation for Elevator Diagnostics
Electrical faults often require the use of instrumentation and other resources. Value: 1 contact hour (0.1 CEU) This article is approved for Continuing Education by NAEC for CET® and CAT®....
Printed Circuits: Reliability for All
Still, faulty operation in elevators must always be recognized as a possibility Value: 1 contact hour (0.1 CEU)This article is approved for Continuing Education by NAEC for CET® and CAT®....
Using a Vector Network Analyzer to Solve Difficult Elevator Problems
Device can help uncover incompatibilities in elevator equipment that may be causing chronic motion-controller outages. Early 19th-century elevators, which made multistory buildings feasible, predated electrical distribution systems. These lifts were...
Motor Controllers
Types, requirements, and diagnostics and repair are among the aspects of motor controllers this overview addresses. The National Electrical Code (NEC), which has jurisdiction over subjects in which it has...
Integrated Circuits
The history, application and maintenance of these important microelectronics components are explored. In the microelectronics continuum, integrated circuits (ICs) are probably close to their midpoint of development. They have progressed...
What Is a Transistor?
Another major electronic component used in elevators is detailed. Like diodes, transistors are major players in the electronics arena, notably in elevator motion controllers and variable-frequency drives (VFDs) that have...
MOSFETs
This article on metal-oxide semiconductor field-effect transistors (MOSFETs) builds on lessons from the prior piece “What Is a Diode?” (ELEVATOR WORLD, August 2014). Metal-oxide semiconductor field-effect transistors (MOSFETs) are similar...
