Hi all, so this is a fun question. I'm buying a bunch of parts from mouser for a home lab. ('Cause they have the laser diodes I want.) So I favor through hole parts, (for proto-typing) R's, C's, transistors...
R's- 1% MF 0.25W 10,30,...300k, 1M, 10M, 100M (the last two not MF.) C's- COG's 1 pf to ?0.01 uF (1, 3.3, 10..) X7R 0.1uF bypass caps Al-electro 100uF/ 100V
2n4401/03 2n7000 lnd150 lm317, LM337What else am I going to want? (forgetting)
George H.
Maybe some parts kits, from Mouser or parts makers.
Opamps. Diodes. LEDs. Trimpots.
Axial 1/4 watt resistor kits are good to have around. Ditto caps and inductors. The resistor leads can be snipped off to make nice jumpers.
Get a mess of cheap coax adapters and banana things from ebay or Amazon. And a supply of double-side copperclad FR4. And some cheap assorted hardware kits.
Somebody should sell an everything starter kit. Probably someone does.
Get a bunch of coin envelopes and Danish Butter Cookie cans to stash things in.
Dremel. Dental burrs.
-- John Larkin Highland Technology, Inc The cork popped merrily, and Lord Peter rose to his feet. "Bunter", he said, "I give you a toast. The triumph of Instinct over Reason"
Depends a bit on what you have already. Storage drawers maybe.
I generally buy just enough bits at a time to qualify for free postage. I don't know if it works the same way in the USA. Keep a wanted list...
-- Regards, Martin Brown
Kit's were kinda spendy.. ~$100. Better would be a parts list from digikey... load this and start your lab.
Diodes!! head slap! and trim pots... I had this trimpot kit from DK... big single turn things, but super useful for protos. (had metal housing that could be soldered to copper clad for support... I need some copper clad too.)
oh and connectors... I've got some old stuff
Right!
Ok my mouser part list is growing. I can probably share it if there is any interest. Oh here's a thing. the cheap LM317HVT (maybe should have an A in there?) LM317AHVT (60V_in TO-220) from On-semi are EOL. (I was going to get 3, but ordered 10 :^)
George H.
I wanted to use an LM317HV in a new design, but it looks iffy, and is only available in ancient packages. I wound up using an OPA547 power opamp as the regulator. It does have a nice resistor-programmable current limit.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Am 05.02.20 um 19:42 schrieb John Larkin:
I have bought some LM350 made by Fairchild from DK. Took the cheapest, got dirt. The tab of the to-220 was nearly a better foil, one tab was lost during handling. Used only 3 of these LM350. Rest is in the drawer for panic events.
:-( Gerhard
How much current? The LTC6090 is a nice HV opamp.
George H.
Order has been sent... the other thing I need for optics is some tip/tilt mirror mounts. I might have one... or thor-labs.
GH
Oh TO-220's with thin tabs... I've seen those too. The tab is almost worthless.. surface mount with power pad and clip for production these days.
George H.
For lowish speed stuff, how about:
Transistors: MPSA18 superbeta NPN PN4250A quiet PNP with good beta D44H11 low sat NPN TO-220 D45H11 low sat PNP TO-220 CPH3910 SMT but no home should be without them BFS17A
Op amps and comparators: (I use a lot of duals) LM358 dual jellybean class B op amp LM393 dual OC comparator, ~1us MC33078 4.5 nV noise bipolar dual (high Ibias but super cheap) TCA0372 1.5A power op amp TL082 FET OPA2188 HV chopper--use a Bellin Systems SO8-DIP breakout (there aren't any good dual choppers in DIP packages)
diodes
1N5817 1A Schottky 1N5823 3A Schottky 1N4148 gold-doped MBD301 SS Schottky 1N4007 1 kV rectifier (slow)Vregs LP2951 Good enough for a voltage reference in many cases LM1117 Lower voltage but low dropout, accurate voltage
MG Chemicals 835 RA flux pen
From eBay: Cu-clad board Kester 44 solder BNC bulkhead connectors
5-way binding posts banana plugs (some are decent, many are junk--YMMV) BNC patch cords #24 stranded PVC-insulated hook-up wireCheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
Well, it's complex. It regulates the programmable voltage into a pulse generator output stage. The output is basically a GaN SPDT switch, a
50 ohm power resistor, and an output connector. The voltage range will be 1 to 45 maybe, and 45 would fry the resistor if someone shorts the output. I'm thinking about maybe a 300 mA current limit, which is about 4.5 watts at 100% pulse duty cycle. But 45 volts times 300 mA is 13.5 watts, which could be dissipated by deliberately sinister programming of pulse duty cycle into a short.Those old-process linear regs would typically stand a lot more voltage than their spec. LM1117 is specified for 15 volts in, but typically dies at 60. I haven't tried a 317 but I suspect similar behavior. But I wouldn't trust that for production.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
You might take a look at stuff on AliExpress. They have both bargains and junk. Check out the diy modules. kits of thing as counters and frequency generators.
They also have resister assortments.
The good news is low prices. The bad news is long shipping times.
Dan
Decades ago, when I was an undergraduate, I cut some ~2" wide aluminum u-ch annel into ~1" wide pieces and put a couple of BNC bulkhead connectors on t hem to make a poor-man's version of the $80 Pomona 2399 boxes.
I am still amazed at how useful these have been for making a custom simple filter, DC block, attenuator, etc, for measurements.
I made one version where I soldered alligator clips to the signal and groun d lugs. I still giggle with joy at how wonderful this is when I use it.
People do the same thing with BNC-to-minigrabber adapters or minigrabber ca bles, but I found that those 3D sculptures are so much less reliable. (Espe cially on a cluttered bench where you need to keep the untrimmed resistor/c apacitor leads from finding other things to contact.)
I make boards, or boxes, out of copperclad FR4. I use 2-56 screws for power and ground, easy to clip to, and SMB connectors for most signals.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
fire up a spreadsheet and fill columns with part numbers, part type, and some ordering info (part#, cost, date ordered, quantity,...) Feel free to add specs that matter to you.
It's a lot easier to find parts in a listing than it is in a bunch of tubes, bags and boxes. I'd second the 'coin envelopes' thing, too. That way, you can keep a LABEL next to the little specks of surface-mount parts (and you WILL accumulate some of those).
Don't forget an assortment of fuses; nothing more irritating than having to pay minimum-shipping-cost to get a common fuse that just can't be got at the nearby Radio Shack. An assortment of power diodes (in case of SMPS failure due to rectifier shorts) is also of use, because it's a lab, and there will be little accidents. Those can be surface mount (some will have to be, others in TO-220 and cylinder-with-leadwires), and won't cost as much as the fuses.
I use die-cast aluminum stomp boxes with copperclad FR4 mounted inside the lid using bulkhead-mount BNC cables, like this:
No EMI worries inside the box (cables are another matter of course).
Cheers
Phil Hobbs
-- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC / Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics Briarcliff Manor NY 10510 http://electrooptical.net http://hobbs-eo.com
I'd seriously consider 0805-size SMT instead of through-hole. I find that prototyping goes faster with those because I never have to turn around the board.
An assortment of wire in different colors, LOTS or alligator clip wire, nuts, bolts, sheet metal to make shields, prototype boxes, fridge, Pale Ale, IPA ...
Nah.
Semiconductors, yes. For a good assortment of discretes I'd look elsewhere first. EBay, Amazon, hobby places.
But watch that waist line :-)
John, you guys should all have your cholesterol levels checked out.
Where does one get dental burs? The ones sold for Dremel tools are a little rough.
[...]-- Regards, Joerg http://www.analogconsultants.com/
torsdag den 6. februar 2020 kl. 00.56.31 UTC+1 skrev Joerg:
they are all over ebay for next to nothing, they also have the highspeed spindles for cheap if you want to moonlight as a dentist ;)
Indeed! John, which kind do you prefer? WR-13? Or the longer TR style?
-- Regards, Joerg http://www.analogconsultants.com/
These were from ebay. They have a soft rounded tip, which carves the copper really nicely. Clean up the carvings with a Scotchbrite pad, then some SoftScrub. Gold plated FR4 solders beautifully and won't tarnish.
Amazon wants you to be a dentist or something to sell you burrs.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
I'm glad you mention that. Question: Is Kester-44 the way to go if you want a clean joint, easy solderability, and you don't need lead-free? In 63/37 obviously.
I recently reviewed the Kester website (for wire solders, not interested in bars), and I really didn't get a complete picture of what's "best" - only some generalized statements as to the reactivity of the rosin used.
For general all-purpose electric repair (through hole and SMD), is "44" the right stuff to get? (I'm getting low..)
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