Hints for techs using Bob Parker's ESR meter(kit)... (ORDER PAGE)
Last updated on
January 8, 2014
Note: this is swiped from Bob Parker's, the designer of the ESR kit's, home page (with permission) with some additions...
Dick Smith Electronics have stopped making ESR meter kits, however Bob redesigned the kit and Anatek is manufacturing them now (Mark III - the BLUE ESR kit) and we are (of course) still selling them!
contact John's Jukes/Flippers.com FIRST if you have a problem with the ESR KIT you bought from us - we carry spare parts and Bob needs time to design more cool kits or just to sleep - he is too often up to 3 or 4AM responding to emails...
COMMON PROBLEMS with newly assembled kits (the older K series from Dick Smith, not the BLUE series at all!):
F1 ERROR MESSAGE: Before doing the self-test, it’s very important to first set VR1 to the centre of its adjustment range and make sure that the meter’s supply voltage is in the range of 8.5-9.5V."
F2 ERROR MESSAGE: with Mark II kit that you just assembled using the enclosed ERRATUM sheet??? If you do the "Optional Modifications" suggestion about replacing the 5VDC regulator (78L05) with the LP2950 you will get a "F2" 'error' display when you turn it on. This is not a cause for concern if the test resistors read correctly.
Bob has asked me to tell you folks that you can use a BRIGHTER LED display in place of the somewhat dimmer ones packed in the kit by DSE (Dick Smith Electronics). Fairchild MAN6980E High Efficiency Red (Common Anode; Right Hand Decimal) LED Single Digit 'Stick' display, or another substitute. Note these draw the same current and your battery life will be the same...
Note at the bottom a neat way to test batteries using the meter!
Another new trick-how to measure both DC resistance and ESR at the same time!
Take a regular digital ohmmeter, set to 200 ohms, and put the leads of it in parallel with the ESR meter! You can glance at the ohmmeter to make sure the cap under test is not shorted, then check the ESR with the ESR meter. Fast and easy way to take care of that nagging worry "Is it low ESR or a short?"
Here's a few hints to help you get more from your ESR meter - MK 1 or MK II
(1) The way to hold the 9V alkaline battery in place is to lay it in the bottom of the case, then place a suitable-sized piece of thick foam plastic over it. Then the circuit board will hold it snugly in place when the front panel is screwed down.
(2) The "Approximate worst ESR values" table on the front of the meter were taken from a fairly old capacitor catalog(ue), and capacitor technology has evolved a bit since then. Many 105 degree C electrolytics have an ESR up to nearly double those values even when brand new, and other electrolytics have a lower ESR even when old. From my experience if an electrolytic has an ESR more than double the table value for its capacitance and voltage rating, it's wise to check it against a new one and/or replace it to remove the chance of it causing problems in the future.
Hank Sievers said, "Bob Parker's meter can also be used as a go-no go type. I have found that I can consider everything below 3 ohms as good, and all over 10 as bad, with very few falling in the doubtful category". I agree that except for very large and very small caps, this is a useful 'rule of thumb'. Thanks, Hank!
(3) The 'DISCHARGE CAPACITOR BEFORE MEASURING!' warning on the meter front panel is a little over-cautious.... 'Test only discharged capacitors!' would have been better. Nearly all electrolytics are discharged by their surrounding circuitry within a few seconds of the power being disconnected, so you can generally poke around with the meter without worrying about this. The only caps which are likely to need deliberate discharging are the main filters in amplifiers and other large power supplies.
(4) Glenn Watkins has pointed out that a shorted or partially shorted cap can check OK (ie: low resistance), so if you check a cap and the indicated ESR seems too good = low to be true, it's wise to check it out with an ohm meter.
(5) The meter puts out regular bursts of 10us pulses at a 2KHz rate, at an open-circuit amplitude of about 600mV P-P. At a pinch you can use it as an audio signal source to check speakers, amplifiers etc. The pulses have a fast rise/fall time, so it would probably make a crude RF signal injector as well. Thanks to 'Kiwi' Joe Lussy for suggesting this!
(6) Glenn Watkins also said, "It's very hard to press the test lead tips together to get a steady reading before pressing the button to zero the display. I found that if the test leads have sharp tips, you can press them both on a solder pad (on a PC board) and the leads will penetrate the solder a little giving a good solid reading". Thanks Glenn!
(7) We all know that varying contact resistance between the banana plugs and sockets can cause unsteady readings, but if you give each plug a big squirt of CRC "CO Contact Cleaner" then rapidly insert and withdraw it in its socket a lot of times, this reduces the problem considerably.
(8) A few techs have suggested that the test lead sockets should have the industry standard 3/4" spacing. When I was designing the meter I tried to achieve this, but unfortunately the plastic mounting pillars in the case are too close together to make it possible, while still leaving room for the push button switch. Sorry about that, guys.
(9) This is more of a note than a hint... The ESR meter kits are now coming out with Zilog Z86E0412PSC microcontroller ICs rather than the Z86E0408PSC referred to in the paperwork. The new chips are functionally identical to the earlier ones, the only difference being that they are rated for a higher crystal frequency- irrelevant in this circuit.
Finally a big "THANK YOU" to all you techs who've bought this meter and said good things about (and constructively criticised) it, both on the Sci.Electronics.Repair newsgroup and to me by e-mail. I really appreciate it!
From email@example.com Mon Jul 27 16:53:17 1998
> Well an ESR meter measures the Equivalent Series Resistance of a
> capacitor. ESR means how well a capacitor passes AC while blocking
> the DC, and the lower the ESR the better.
FWIW, I've had good luck using my ESR meter to debug hum problems in audio
circuitry, where the difference between ground and a few tenths of an ohm
to ground can mean an induced voltage.
--Walter Harley -
Borrowed (with minor changes) from "Circuit and Design Idea" which was published in Electronics Australia magazine back in about April/May this year (1999).
For a built " (1999) Bob Parker's excellent ESR meter (January 1996) will also test all types of cells and batteries.
Used in the normal way, a cell's 'effective series resistance' shows on the meter's display, indicating its ability to deliver current and voltage regulation. All cells have an ESR characteristic of cell type, size and state of charge. For cells of the same size, NiCads have the lowest ESR, followed by alkaline, Ni-MH, carbon-zinc and others.
Flat and faulty cells will have high ESRs. A dry cell's ESR increases as it is used, going high when flat. A rechargeable cell or pack can be measured while on charge or load, provided the current is steady. Even the tiniest button cells may be checked, as there is no load current.
A high ESR reading may reveal damaged cells or a bad internal connection. All tests are instant and require no other equipment. Checking and matching new cells is another application; the table of typical readings for good cells will help get you started, until you create your own database." Lead-Acid batteries should also be able to be tested...
Internal resistance of batteries
Submitted by: Phil Allison, Sydney, edited August 19, JR...
Editors note: While this is an interesting item I have not followed up on it - perhaps someone can provide me with an updated chart of their results - either confirming or denying the use of the ESR meter for monitoring battery condition. John :-#)#
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CLICK here if your kit doesn't work after trying the troubleshooting instructions in the manual. If you can't sort it out then Please contact us (especially if you bought the kit(s) from Flippers.com) for parts or service before sending a note to Bob Parker - the designer of the kit.