We've been doing pretty fancy test sets lately, rather than hacking things up. Long term, it's worth it.
We were going to plug a fan into the FAN connector, to blow air over various DUTs, but the BLDC fans make a lot of power supply ripple. So we'll use a separate wall-wart to power the fan. Amazon has some cool little USB fans. This one is nice:
The pot controls speed.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
What kind of DUTs would you typically be expecting to check with this?
Are there "real" switches and pots underneath the knobs? (what kind of pots?)
George H.
It's missing a display.
--
Thanks,
- Win
This board tests a bunch of different laser drivers, like the text says. Most of them need cooling of some sort, either air or conduction cooling to a baseplate.
We'll have a big aluminum plate with this board bolted down. To the right will mount various DUTs, and then dummy loads that simulate the laser. The testing won't be very automated.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Yes, real ones, not encoders. I can get you part numbers if you're interested. The big switch and the pots feel really good.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
The scope and the DVM have displays!
Are the OLEDs any good? Do the pixels wear out?
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Nice. I like the idea.
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 hobbs at electrooptical dot net http://electrooptical.net
The upper right label "LVDS Trig in'; shouldn't that read 'LVDS Trig Balun In' ?
General-purpose setups are nice; a project by some buddies of mine required a host of complex cables, and rather than hand-test all of them, they designed and built a tester for all short and open faults, fitted with the correct connectors for all of the cables being used.
It took 'em a week to put the tester together. All the project's cables were test-complete in three hours. The tester was shelved, no one had the heart to throw it out.
There is a company that makes cable testers. They started by making testers for Drive in Theaters. Hence the name Dit-mco. They use an Amphonol 100 pin connector on the tester and then use adapter cables to connect to the DUT.
So perhaps you could rent your tester to companies that fabricate cables. Or get into the manufacturing of cables.
Dan
That Amazon thing looks awful.
The Arduino crowd are using SPI and parallel versions of this, with touch-screen support:
Beware; there are a half-dozen different controller chips, not all well-supported. It's pretty easy to write good user interfaces however, and they just plug into the top of an Uno, which in turn can plug in to your test fixture, so it's really very easy.
Clifford Heath.
There is a TTL-to-LVDS converter chip on the board. Some of the laser drivers accept LVDS on their ribbon-cable interfaces.
Here is our universal mega-tester board:
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Is it "ganging up" (by that I assume you mean some interaction between the two) or is it just that there is too much inductance in the wires between them and your buck's input is oscillating?
The oscillation frequency is too low to be explained by inductance. I think the negative input impedance of our switcher is somehow trashing the loop stability of the switching wart. The cap fixes it, somehow.
Our switcher is two paralleled LTM8023's, which probably makes the dynamics even more interesting.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
I'm guessing it's academia. George H.
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