Our recent discussion about checking capacitors for equivalent series resistance continues with tips from two engineers with plenty of field experience.
The first is from engineer Ed Treese. Ed writes about a capacitor checker used by several engineers in the Kansas City area. Made in Independence, Mo., by Midwest Devices LLC, the product is the Capacitor Wizard, “invented” in 1995 by Doug Jones, who also does a great SBE meeting.
The Capacitor Wizard measures ESR with the capacitor “in-circuit.” Its ESR meter’s low input impedance, simplicity of use and real-time measurements still make it the fastest and most reliable ESR analyzer around.
I checked it out on www.midwestdevices.com. One of the things I like is the information printed on the meter’s front cover. It explains what constitutes normal readings for a “good” capacitor — no digging around for the tech manual when you make a measurement!
Doug also shares 10 helpful “Tech Notes” about ESR on the website.
The Capacitor Wizard is available online for $229.95.
Ed ended his tip by writing that he was pleased to see the comments from John Collinson in Workbench. (John was a chief engineer/contract engineer in Kansas City for many years before he moved south to warmer climates.)
Fig. 1: Greg’s Muir’s assortment of Peak analyzers.
Fig. 2: The meters fit in a compact travel case.
Wolfram Engineering principal Greg Muir offers more thoughts about ESR, as well as a suggestion for general component diagnosis.
Our previous article tweaked Greg’s memory about something he meant to write a few years ago. He’s sure that there are engineers who have arrived at a remote transmitter site — probably in the middle of the night — armed only with basic test equipment but facing the challenge of trying to repair equipment. And sometimes it’s difficult to determine whether a component is defective or out of the manufacturer’s specification.
When you find the problematic part, the task then becomes finding a possible on-site replacement to get things working again. So the engineer starts to look through miscellaneous electronics parts amassed over the years for something that might serve the purpose.
It’s not uncommon that some of these parts do not necessarily carry an industry standard part number, making the task even harder and resulting in a hit-or-miss substitution situation.
After experiencing this over the years, Greg decided to find a solution to minimize head-scratching and wasted effort. He came upon the Atlas series of component analyzers made by Peak Electronic Design Ltd. in the United Kingdom.
Fig. 3: A closeup of the component tweezers, ideal for checking surface-mount and high-density components.
Fig. 4: All packed up …
Pondering what would be most handy in the field, Greg chose the following units:
Atlas LCR45 passive component impedance meter
Atlas ESR capacitance and equivalent series resistance meter
Atlas DCA semiconductor component analyzer
Atlas SCR triac and thyristor analyzer
Given their small size, you can put a nearly complete array of needed component test equipment in a small carrying case.
Over the years, Greg has found these instruments to be real lifesavers. They are easy to operate (one button); do their own analysis of the device under test; and perform surprisingly well when compared to more expensive lab equipment.
The instruments won’t provide every test parameter specified by the device manufacturer, but they do serve to provide a reasonably accurate indication of what is needed.
MCM Electronics carries Peak analyzers, and offers reduced prices on the instruments from time to time. In addition, its waterproof transit cases are an economical solution for keeping your analyzers together and protected.
Greg also purchased Peak surface-mount tweezers, which allow connection to the LCR45 and ESR analyzer test leads, so you can probe those tiny passive components quickly.
Fig. 5: … and ready to go!
Peak has other models available and has come out with upgraded and some new units that provide a more detailed analysis of a component.
Greg has determined that one does not need to approach test lab conditions when trying to get back on the air and fielding phone calls from the studio.
Got a test instrument you can’t do without? Tell me about it and earn SBE recertification credit for published submissions. Email or fax your suggestions along with high-resolution photos to [email protected] or (603) 472-4944.
Author John Bisset has spent 46 years in the broadcasting industry and is still learning. He handles West Coast sales for the Telos Alliance. He is SBE certified and is a past recipient of the SBE’s Educator of the Year Award.