Category:Electronics Lab

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Zone Information
Eroom-pano-resized.jpg
Zone Name Electronics Lab
Zone Slogan "Strong enough for a professional, pH-balanced for a noob."
Zone Coordinator(s) Nate Bezanson
Zone E-mail elab@i3detroit.org
Map Area B
Zone Color Yellow
Eroom-pano-resized.jpg
NewERoomWithOverlays-output.jpg
I3detroit-eroom1.jpg

Welcome

Please leave the zone cleaner than you found it. Being able to find things again is important! When in doubt, please ask. (Or email the ZoCo, above.) We're here to help each other make cool stuff.

Philosophy and guidelines

This is what we make it, so please help make it the best it can be.

Please wipe the workbench clean as you prepare to leave. If the floor needs vacuuming, pick up the snaggy bits and start the robot!

In-between values could be in either place. So a 20k resistor could be in the 18k or the 22k drawer, either is OK. And a SATA-to-SD adapter could be in the SATA bin or the Flash Memory bin. It's a balance between being easy to put things away, and being able to find them with a reasonable search.

Donations of components and equipment: Please ask first! (Or email the ZoCo, above.) If you can't ask, at the very least, tag the donation as such -- otherwise we may run ourselves ragged trying to figure out who lost their treasured stuff.

Please reimburse for any components that leave the lab. Exception: If you're using less than a dollar worth of stuff today, don't sweat it -- just build awesome things and share them!

Some components have their reimbursement cost labeled on them -- this is roughly what it costs us to get more. If there's nothing labeled, look it up and assume we're buying at the first price-break, then tack on a bit for shipping. If you want to be generous beyond that, awesome! That's what helps us grow.

Stuff not in the drawers (that is to say, in the bins or shoeboxes) may be for taking home, or may need to remain here -- Ask! Some help in figuring out how to manage and label that stuff would be welcome.

Approximate cost of some common components

Rather than tagging each value individually...

Item Price
1/4-watt resistor: 2c
1/2-watt resistor: 5c
High-wattage resistors: Ask!
3 or 5mm LED, red/green/yellow 5c
3 or 5mm LED, white or blue 10c
High-power LEDs Ask!
Any ceramic cap 5c
Electrolytic caps Use Mouser, or ask
Zener diodes, up to 1W 10c
1n4xxx diodes 5c
Other diodes Use Mouser, or ask
0.100" Harwin housings, 1 position 2c
0.100" Harwin housings, 2 positions 15c
0.100" Harwin housings, 3+ positions 25c
0.100" Harwin crimp pins 7c


Table of Equipment

Equipment Authorization Owner(s) Status
Schott Binocular Microscope No Andrew Meyer Running
Bluecam No i3Detroit Running
Soldering Station - Edsyn Loner No Nate Bezanson Running
X-Tronic 4000 Hot Air Rework Station No Unknown Running
Antenna Analyzer No Brad Tarratt Running

BusPirate

Saleae Logic analyzer

TL866 Universal Programmer


TODO List

The following list is an attempt to offer up suggestions of tasks that could be accomplished in the Electronics Room by people interested in helping out.

Feel free to take charge of one or more of these items as your time and expertise allow. If you have taken charge of a task, please put your name into the field next to the task.

Should you run out of time or ability to complete a task, make sure to post on the mailing list and "fail loudly". This ensures that task status is shared, and no task languishes in silent failure.

Task Name Description Priority Champion
Populate ToDo List Add a list of things that are needed/wanting to be done in the eRoom. 1 Nate B.
New power for archway lights Replace the brick above the ceiling with something rated for that use and not connected by a flexible cord. 2 Nate B.
Fix the Roombas At least one of the Roomba vacuums has a charging problem that we can fix. New FETs are in the "SMT Crap" bin. 1  ?
Partslaser mechanism Build X-Y gimbal, motor controller, laser enable, and camera mount  ?  ?
Partslaser software Spreadsheet/database, label printing, find-a-part interface  ?  ?
Cabinet map Until Partslaser is operational, an easier way to update https://www.i3detroit.org/wiki/File:NewERoomWithOverlays-output.jpg would be nice. 2  ?
Improve lightbulb load-box Add a temperature-controlled exhaust fan, and corresponding intake grille, to the load-bank box. 3  ?
20A plug on CZ strip Replace the temporary 15A plug on the compute zone power strip  ? Lego
wire spool rack Design a (laser-cuttable?) rack for small wire spools, that hangs on pegboard or under shelf  ?  ?
equipment pages for the keysight gear wiki zone task? find the right template and make stub pages for the MSOX4154A, the E3631A, the 33600A, and 34461A.  ?  ?
tenma meter repair Fix the sticky ammeter needle on the Tenma 72-630 PSU. Gently!  ?  ?
mount bigass HP PSU under shelf Nearest the door, so it's not in knee-space but the meters are accessible 3 ?
surplus equipment ownership determine ownership of LeCroy scope, old HP logic analyzer, magnifying rolling lamp 1 Nate B.
simpson microohmmeter refurb readings aren't consistent, maybe because the internal nicad pack is missing? 4 Evan?
NTSC vectorscope repair PSU problem? 4 ?
mount tek rack stuff on e-cart the new tm506 and sorensen PSU could use better mounting on the rolling cart 2 ?
cull crap on topmost shelves either side of the window, there's a bunch of stuff we never touch, that space could be better used. 3 Nate B.
New test-lead rack for scope probes the existing one was adequate but is a bit rough on probes, a "real" pomona rack would be nice, possibly https://www.zoro.com/pomona-test-lead-holder-black-10-slots-4408pom/i/G7586774/ 1 ?
Clean/repair switch on Ted's PSU Ted brought in this adorable little HP power supply but the gauge is flaky and I think it's just a bad or dirty range selection switch. Needs a good check-out, though. Spikes bad. 2 ?
Clean other HP HV PSU Scored a nice HP PSU at auction that seems to work but the pots and switches are flaky. It's in overflow with a tag on it. Have at! 2 ?

Meters

(Just a copy of a post on the mailing list, feel free to pretty this section up and remove this note.)

Instruments-1.jpg

Referring to the numbered photo:

1: "Fish" scale, 50lb or thereabouts, hook style. Often the easiest way to measure a weight or force, this thing's built tough and has been with us since the Royal Oak days. Owner: Nate B.

2: Kill-a-watt or similar plug-in AC wattmeter. We have several of these. Useful not just for load measurement ("Can this run from that extension cord?"), but also power factor, voltage sag under load, etc. Owner: Various.

3: Logic Dart. This is like a pocket oscilloscope except it doesn't do analog -- it's a multichannel logic analyzer and even disassembles a few protocols. Incredibly useful for things like async serial troubleshooting, but the probes and wires are delicate. Owner: Ted Hansen.

4 and 5: Noncontact AC "volt-sniffers". Beeps in presence of AC field, use as a first quick-check to find live wires. Never trust your life to this; always verify with an actual meter before beginning work! Owner: Various/unknown.

6: Noncontact AC volt-sniffer built into flashlight. Push button to turn on white LED, and blue/red LEDs indicate presence and relative intensity of field. Usage same as above. Owner: Nate B.

7: Three-light AC outlet tester. You know this one. Trivia: Solid-state relays (and triac-based dimmers) in their "off" state can allow enough leakage to light the neon lamps in this tester. Confusion ensues! Owner: Nate B, perhaps others, I think there are a few of these around.

8: LCR meter. That's L for inductance, C for capacitance, R for resistance. This is the cheapest of the cheap, and doesn't work on very high or very low values. Also operation if you select the wrong component type is unpredictable. Also sometimes it's just plain unstable. But it works, mostly. (A better LCR meter is on the wishlist.) Use for sorting or checking capacitors prior to use. Owner: i3.

9: Laser distance meter. Seriously consider reading the manual, this has way too many features. By default it seems to figure its own body into the length measurement, but I'm sure that's configurable if you don't want that. Surprisingly accurate. Owner: Nate B.

10: Ultrasonic distance meter. Purchased before, and obsoleted by, the superior instrument above. Still somewhat useful for assessing the ultrasonic reflectivity of materials, also perhaps annoying dogs or bats. Owner: Nate B.

11: Sound pressure level meter. Uncalibrated but still useful for relative measurements, has A- and C-weighted filters. Owner: Nate B.

12: Light intensity meter. Measures in lux, can manually convert to footcandles or whatever. Supposedly weighted to human sensitivity curve but I find this claim dubious given its price. Uncalibrated, obviously. Too sensitive to measure direct sunlight; use neutral-density filters to stop it down and then adjust your math later by comparing to a known light source. Owner: Nate B.

13: Inline DC wattmeter/ammeter/hourmeter: Replacement for the similar-but-larger Watts-Up meter (which met an untimely end when its max-voltage spec was exceeded), this one has more features but seems less accurate. Anyone with ideas for calibration, have at and let me know what you find! Super handy for measuring battery charge and capacity, device load, etc. Sadly only measures in one direction so not useful as a battery coulomb-counter. Owner: Nate B.

Second photo: Three-mode tachometer. With the nose detatched, this is a photo-tach that measures reflective dots on a belt or rotating object. Snap on the nose, and it measures RPM as the spinny bit is pressed against a shaft end, with 3 different conical attachments for contact. Swap out the cone for the wheel, and it measures surface speed of a belt or whatever. Please keep all the accessories with it in the box! Oh, and RTFM before using the wheel, there's a scale factor... Owner: Nate B.

Not pictured but lives behind the other-meters bin: West Mountain Computerized Battery Analyzer III (CBA3). A computer-controlled resistive load with a calibrated ammeter, you charge the battery with your usual charger, then use this to discharge it and see how much power you got out. Software is on the CD in the box. Owner: Nate B.

Also recently joined: Simpson micro-ohmmeter, not yet set up and working; we need to make some BNC-to-Kelvin clip leads for it. And then sanity-check it with a few known low resistances. But then it's an amazing tool for measuring wires and other resistances below the range of typical multimeters. Owner: Evan?


Reference

Some resources I've found useful for learning soldering, for those like me that prefer a good video over reading a website:

Pace Basic Soldering Lessons: http://www.youtube.com/playlist?list=PL926EC0F1F93C1837

Pace Rework & Repair Lessons: http://www.youtube.com/playlist?list=PL958FF32927823D12

TopLine component package types: http://www.topline.tv/DummyClass101.pdf

Tangent Tutorials: http://tangentsoft.net/elec/movies/

What's that? A collaboratively-edited collection of parts that hobbyists actually find useful? Yes! Behold, the Partfinder! http://www.ladyada.net/wiki/partfinder See also Dangerous Prototypes' collection: http://dangerousprototypes.com/docs/Partlist

There's a trove of 7400-series datasheets here: http://www.skot9000.com/logic-datasheets/

Gorgeous printable reference sheets: http://www.akafugu.jp/posts/resources/reference-sheet/

Nate B's personal bookmarks on the subject are here: http://delicious.com/myself248/electronics

Please feel free to edit this section and add more links!

SD card adapter schematic, we stock these in the store.
TL866 bin contents