Using a Cypress PSoC5 to Sniff Out PCB Shorts

RE: Using a Cypress PSoC5 to Sniff Out PCB Shorts

tpcipri — Tue, 15 Oct 2013 03:04:22 GMT

When I first developped this concept it was using a $10,000 HP3452 6 1/2 digit DMM. The point of this BLOG was to show how you can use a low cost development kit to accomplish the objective. There are lots of cool embelishments you can do. For this simple application all you need is a current source and good ADC.

RE: Using a Cypress PSoC5 to Sniff Out PCB Shorts

johnbeetem — Sat, 12 Oct 2013 18:47:39 GMT

I once had a nifty gadget called a Short Squeak. It was a probe-shaped milli-ohmmeter with audio output, which would increase in pitch as you got closer to the short, basically working as a variable-frequency oscillator controlled by resistance. Great tool, plus the sound drives your colleagues crazy so they go away and leave you alone [View:/resized-image/__size/16x16/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-19a55701-6497-4305-94e0-f114488ffb83/contentimage_5F00_1.png:16:16]

It would be pretty easy to add audio to this PSoC5 application.

RE: Using a Cypress PSoC5 to Sniff Out PCB Shorts

hlipka — Wed, 09 Oct 2013 09:47:58 GMT

I cannot find the "ADC_DelSig Example project", neither in the Creator 2.2, Creator 3.0 nor in the PSoC5LP-050 kit examples. Maybe you can add your project here?

Can you also add a somewhat larger image so we can read the resistor values properly? Especially R1: It seems to read 1Mohm, but this would be wrong. For each 1µA sourced by the IDAC, there would be 1V drop over it, so we could work only with really low currents.

Can you explain how the design "limits the voltage to 100mV"? How does it work in case I connect the leads on J1 to a higher resistance (traces without a short) - the the IDAC will increase its output voltage until its programmed current is reached, even if this means the voltage is higher than 100mV...