|VK5JST HOMEPAGE- PART 12|
|An ESR Meter For Electrolytic Capacitors (and Low Ohms Meter)|
IMPORTANT NOTE- November 2014 In the original article published in Amateur Radio magazine September 2012, use of a 1mA FSD meter was specified. It has recently emerged that some TL082 ICs on sale are counterfeit, and are incapable of supplying enough current to correctly drive a 1 mA meter. The result is a meter scale with a very cramped top end (low ESRs). Unhappily, these counterfeit chips are indistinguishable from the real thing. However, they will successfully drive a 100 microamp movement, and it is thus recommended that this meter sensitivity is used so that the project will work successfully every time it is built. All documentation has now been rewritten to effect this change.
However, the 1 mA meter can still be used if desired. Please see the comments in the revised text of the original article below.
This project was published in the September 2012 issue of the Australian magazine "Amateur Radio", and has been designed using parts which are very readily available (see the circuit and parts list). There is little point in supplying a kit of parts to amateurs who have been around a while - most will be in your junk box. However, the printed circuit board (1.6 mm thick FR4 fibreglass, 35 micron copper, easyflow lead- tin solder coated, plated through holes, solder masks, component silk screen) is another matter, and is available to hobbyists only, here.
BEFORE YOU SEND ME YOUR MONEY, check that boards are in stock by emailing me (Jim) at the following address, then click on the Paypal button.
PLEASE NOTE THAT ORDINARY AIRMAIL IS USED FOR SHIPMENT. THIS MEANS THAT ALL FORWARDING OCCURS AT YOUR RISK UNLESS YOU SPECIFICALLY REQUEST (AND PAY EXTRA FOR) FORWARDING BY REGISTERED MAIL.
ESR METER PRINTED CIRCUIT BOARD.........$A10.00 plus post and packing
Download the files for the "ESR Meter" here by clicking on the appropriate link :-)