Bob Parker ESR Meter

Aaarrrgghhh !!!! That is a calamity ! Bob get on here and sort this man out immediately !

Arfa

Andrew Tweddle wrote in news:456b7e31$1 snipped-for-privacy@news.chariot.net.au:

Bad leads or worn jacks/plugs? Loose nut on the jacks? Bad solder joint at PCB or at jacks?

Maybe the ESR meter's caps have bad ESR? ;-)

(ironic humor,folks)

--
Jim Yanik
jyanik
at
kua.net

For what it is worth, I had a similar problem just a few days ago. Look at the meter leads to make sure the connection to the probe and banana jacks are solid. Since you are measuring very small resistance, a poor connection will cause the meter to wander all over the place.

I was given an old Tektronix scope about 1990, I guess the 545 (the one from about 1959 with the plugins), and a few years later there was ripple in the display. I actually figured out which one it was by putting the probe on the various B+ lines until one of them caused the ripple to double in amplitude.

I was surprised that when I got to the local "surplus" outlet, they actually had electrolytics of enough voltage and enough capacitance, for virtually nothing. My recollection of high voltage electrolytics was their relatively small value, and these were comparatively high (not thousands, hundred, of uF). Yet when I needed some higher capacitance high voltage electrolytics, there they were, handy and cheap.

Michael

And don't forget the leads themselves! My meter has plenty of use & I've had to cut back the leads a number of times, they tend to fracture internally at the ends where they flex the most.

PS, I gave up on the banana jacks 'very' early in the piece & hard wired the leads in ... you'd be amazed how much resistance they have even when they're clean.

--
Australia isn't "down under", it's "off to one side"!

stanblaz@netspace.net.au
www.cobracat.com (home of the Australian Cobra Catamaran)
www.parkdaleyc.com (where most of them sail)
http://groups.yahoo.com/group/cobra-cat/

to

That is a good idea. I think I will do the same the next time.

If you bought the ESR meter kit from us (John's Jukes Ltd. aka FLIPPERS.COM) and installed the MOV, please disconnect one lead of the MOV. A problem has arisen that is outside of the design specs for using this as input protection. I hope to have a cure soon, but this is NOT Bob Parker's design problem, rather it was my attempt to protect the ESR kits from overvoltage spikes/charged caps that is unfortunately going wrong.

I am going to try to add a pair of back-to-back diodes in SERIES with the MOV to see if that cures the error that the MOV introduces to the meter. Just haven't had a chance to test that idea out fully...

Sorry about that!

I am going to send out a note to everyone that bought a kit from us so they don't blame Bob!

John :-#(#

--
  (Please post followups or tech enquires to the newsgroup)  John's 
Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9      Call 
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)            
        www.flippers.com              "Old pinballers never die, they 
just flip out."

This one came from DSE.

Andrew

POTM

Hi John,

I would have emailed you directly but it appears that your email address is a spam filter.

We developed a protection device for the Dick Smith ESR some years ago. Since we terminated our relationship with Dick Smith, we no longer offer Bob's fine design.

Perhaps you would be interested in our protector? It does not interfere in operation of the ESR meter in any way, can handle up to

400 volts of charge and also discharges the capacitor slowly to avoid damage to it. Back to back diodes do not control discharge currents but our device does.

Bob Parker checked out our design and approves of it. By the way, the design is patented.

If interested email me at john at anatek dot mv dot com

John Bachman AnaTek Corporati>>

Actually the email address I use for posting to newsgroups IS valid. Handy owning your own domain name, and think about how the spam harvesting programs are likely to treat my email address...

John :-#)#

--
  (Please post followups or tech enquires to the newsgroup)  John's 
Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9      Call 
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)            
        www.flippers.com              "Old pinballers never die, they 
just flip out."

Howdy, I unsubscribed from this newsgroup about a month ago, when I got tired of it looking like the TV guide to the Saturday morning children's cartoons. I only discovered this thread by doing a Google search for ESR meters in case anyone was having a problem. It's a subject which is almost never mentioned any more. I think that all the likely causes of the readings becoming very unstable have been covered by others in this thread. The most likely problem would be something to do with the test leads, like fractured wires from a lot of use, or the nuts on the test lead jacks working loose over time, as has already been mentioned. There's a page of fault-finding info on my website at

which *might* be of some help...

Bob

Thanks for asking. :-) If you're in North America, the only sensible place to get one from would be John's Jukes in Vancouver, Canada. His website's at

If you're in Australia, you'd just walk into a Dick Smith Electronics store. Remember that this is a kit unless you buy one fully built from John's Jukes. The EVB ESR meter which is made in Portugal is almost exactly the same thing, see

Bob

Thanks! I'll have to check into one.

You're welcome. You better get a few user opinions first, because some people don't like that design very much.

Bob

Well, since you've mentioned/suggested it - here I am - opening my ears or is it "eyes" to any suggestions on ESR meters.

Thanks again to Bob and to all who may leave suggestions/comments.

Lou

You could start by looking at the comparison of various ESR meters on the Anatek website at...