Transistor Diode Capacitor Curve Tracer - Page 1
Forum section: electronics / testgear

author: Electro Fan
author_rank: Super Contributor
timestamp: February 02, 2015, 08:02:23 am
content: Anyone ever use one of these or something similar?http://www.ebay.com/itm/Transistor-Diode-Capacitor-Tracker-Curve-Tracer-Tester-With-Probes-BNC-Cables-/161294643173http://www.ebay.com/itm/Complete-Transistor-Diode-Curve-Tracer-Electronic-Component-Tester-/161562431403?pt=LH_DefaultDomain_0&hash=item259ddf0fabI guess it falls in the category of "Octopus Tester"?Thoughts?Update - answered by own question (did a search); looks like this has been discussed:https://www.eevblog.com/forum/beginners/dirt-cheap-and-simple-scope-based-component-tester-curve-tracer/- but still up for any recommendations/thoughts on anyone's favorite designs, kits, or assembled products

author: Bryan
author_rank: Frequent Contributor
timestamp: February 02, 2015, 11:15:24 am
content: Except you could build one for about $10.00. Lot's of schematics and DIY out there. Geez for $60.00 I would expect something more professional looking.

author: GreyWoolfe
author_rank: Unknown
timestamp: February 02, 2015, 01:12:07 pm
content: Take a look at this circuit from Alan, W2AEW:I built it and like it. I had to buy the transformer, but had everything else and I stuck it in an enclosure that I had lying around. Useful bit of kit, give it a squizz and Dave would say.

author: kwass
author_rank: Frequent Contributor
timestamp: February 02, 2015, 02:58:50 pm
content: The Fluke 867b graphical multimeter has a deluxe version of this as a built in function.http://assets.fluke.com/AppNotes/Multimeters/gmm-app4.pdfI've never seen it in any other graphical multimeter, but I have no idea why. It's a useful function that seems easy to implement.

author: Electro Fan
author_rank: Super Contributor
timestamp: February 02, 2015, 09:19:07 pm
content: In looking around I found that maybe there is an easy way to build one of these if you have a function generator.I saw this video and tried to duplicate the layout:I'm not 100% certain of some of the settings and values. Below is an image showing the recommended layout and some possible values - but these values don't seem to be yielding the signatures shown at the end of the video.If anyone here is up for duplicating the test layout in the video please post your recommended values (for the resistors, the function gen, and the scope). Thanks

author: Electro Fan
author_rank: Super Contributor
timestamp: February 03, 2015, 08:49:59 pm
content: This is pretty much the info I was looking for in case it helps anyone else. The articles present illustrations and explanations of curve signatures ("Analog Signature Analysis"). It seems that the test circuit is simply a breadboard and resistors plus a scope and a function generator with standard cables and test leads. I think it's a good teaching/learning tool as well as a useful testing tool.http://www.saelig.com/supplier/saelig/An%20Introduction%20to%20VI%20TestingP.pdf- similar to above, somewhat edited version:http://www.electronicproducts.com/Test_and_Measurement/Benchtop_Rack_Mountable/An_analog_signature_analysis_primer.aspxAnother article of a similar nature:http://www.qsl.net/kd7rem/pdf/octopus.pdfA footnote:One item that had me confused was that some articles show capacitors with horizontal elliptical signatures and others show vertical elliptical signatures. This is explained by the top (and second edited) article as follows:The signature of a capacitor is an approximate ellipse. Capacitors with relatively low values have flattened, horizontal, elliptical signatures and capacitors with relatively high values have flattened, vertical, elliptical signatures. The optimal signature is a nearly perfect circle, which can be obtained by selecting appropriate test frequency and source impedance. Typically, the higher the capacitance, the lower the test impedance and frequency. A leaky capacitor would give a sloping curve due to the effective resistance in parallel with the capacitor.