Products > Test Equipment

CA4810A Curve tracer

<< < (4/4)

mawyatt:
This Curve Tracer doesn't look very well made, lots of sloppy assembly and attention to details. Makes one wonder about the actual design, and agree it should be relatively easy to maintain but seems destine to early failure by the looks of things you've uncovered!

Might be interesting to see the actual waveforms utilized for testing, if you have the time could you hang a scope on the collector and base? Suspect the Collector waveform is a scaled Mains line voltage and the Base steps are synched to the Mains. Also, an easy verify of the relative accuracy of the knob & scale settings and actual applied signal, one can use a precision resistor as the DUT.

One thought, since the warranty isn't likely worth much, would be to tap into the Sweep (Collector) waveform for X axis and Current referenced waveform for Y axis for external output to a DSO so one could capture screen shots from the DSO, or better yet a digitizer for X and Y axis for post processing with a PC or Raspberry Pi. We've already seen some folks creating some really nice Curve Tracer plots, so thinking the CA4810A could be adapted for such!!

https://www.eevblog.com/forum/testgear/show-us-your-curve-tracer/

https://www.diyaudio.com/community/threads/intelligent-curve-tracer-3-0-release.205733/

Anyway, nice video and thanks for taking the time to post :-+

Best,

jord4231:
I would also suspect the collector and step gen are derived from the AC mains, there are two controls looping and compensation it will be interesting to investigate these and check out the waveforms. I will do this in part 2

As mawyatt said the attention to details / assembly are sloppy, with high voltages present this can bring safety concerns.
I wonder if the ST branded parts are fake (probably)

Digitizing X and Y with a Raspberry Pi sounds like a great project I'll add it to my to do list.

A Eevblog member asked if I would purchase this again.
My answer is it depends...
If you are looking to put this in to commercial use I would look at something better.
If you are a hobbyist and love modifying things and are prepared to fix it when it fails AND you can get it for a decent price go for it.
Truth be told one of the reasons I purchased it was to look inside it and make a video!

Depending where you live you might be able to find your self an old Tek curve tracer but then again you might need to put some work in to that too!
In Australia IF you can find an Tek the price is just bonkers.
I found one in Australia listed on ebay a few years ago for $1000 buy it now.
Still kicking my self I missed it by a few seconds. It was listed for less than 2 hours before it sold.
Then there is the risk of importing one.
One day I will find one.....

With the CA4810A I was covered with buyer protection, I was also curious how that was going to pan out if needed.
At one point when I received a notification the box label was unreadable I thought it was going to be smashed for sure!

Anyway thanks for the comment and thanks for watching the video.

David Aurora:
Looks about as expected overall, though I was surprised to see the simultaneous display of both DUTs, that's pretty cool. I couldn't really see, is there much control over that feature as far as positioning/switching rate? Any noticeable effect on measurements in that mode?

As far as the digitising thing, the easiest way I found for the 576 was tapping off the deflection plates via a little adaptor circuit I built up to attenuate and offset. I tried a couple other things but doing it this way meant that I can move stuff around with the curve tracer display controls and the digitised version will always match what I see on the CRT. The only catch is that you need to tell the software what the range is any time you change vertical/horizontal settings as the digitised signal is always just a scaled display (in other words, the digitiser never sees a 0-1V or 0-1000V or 0-500mA signal, it sees whatever voltage it takes to drive the CRT from 0-10 divisions regardless of your test voltages/currents). Obviously if you could be assed you could set up auto range switching with a bunch more wiring and code, but so far I just save templates with the correct ranges for parts I test the most.

Navigation

[0] Message Index

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod