John Beigel, a consultant for MEDER electronic, a manufacturer of reed relays, took exception to my reed-relay bounce-time data, obtained from a Keithley Instruments handbook, and responded, "The vast majority of reed relays are single pole single throw (SPST) normally open contacts. The majority of the contacts close completely in approximately 0.5 milliseconds. This includes bounce. Bounce typically lasts about 100 to 150 microseconds. On new reed relays the operate time is typically 100 microseconds max with a bounce time of 50 microseconds maximum. The bounce time called out by Mr. Titus--'a few milliseconds'--is simply not true."
I obtained sample relays from MEDER and measured relay-bounce times of about 50 microseconds. But other electro-mechanical characteristics as well as test-and-measurement applications also govern the use of relays. Read my follow up column set for the August 2011 issue of Design News. --Jon Titus
Truchard will be presented the award at the 2014 Golden Mousetrap Awards ceremony during the co-located events Pacific Design & Manufacturing, MD&M West, WestPack, PLASTEC West, Electronics West, ATX West, and AeroCon.
In a bid to boost the viability of lithium-based electric car batteries, a team at Lawrence Berkeley National Laboratory has developed a chemistry that could possibly double an EV’s driving range while cutting its battery cost in half.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.