Home lab parts

In addition to Mouser, Digikey, et. al. There's mpja.com -- although you can also get a lot of what they carry on Amazon. A lot of Chinese stuff, but a surprising amount of it is actually quite acceptable.

Cheap bench power supplies, for example.

when you need a switcher for a few prototypes it is much simpler to just use a dirt cheap module, as an example:

I find the same. Also buy some PCB with a grid of individual PTH. I have some on a 0.05" grid, good for small parts. No ground plane for RF work of course.

You can buy complete R and C sets in plastic books (like 20/ea of a thousand values) for $50 on AliExpress. NPH caps too, but thy cost a little more.

Here are some of mine:

Transistors:

2n7002, IRLML6302PBF, BC327, BC848, MMBT2222, MMTH10, BF862, BFR93A

Diodes:

1N4148W, BAV99, HSMS-286K, varactors, zeners

RF: SA612, AD8307, crystals, MMICs

Analog: MC33202, AD8009, LMH6609, others

Power supply: AMS1119, (need new buck&boost choices), USB power packs (for battery ops)

Connectors: SMA, USB, U.FL

Compute: Arduino Nano with my 3v3 conversion, STM32s

I cut the bottom off our (square base) HDPE milk bottles, to the depth of a set of drawers. They make zero-price tubs that are easy to store and rearrange. Use stick-on paper labels.

CH

Good point. And I agree! I had forgotten about those. I usually have about a half-dozen of the 3-amp adjustable ones around. Can't beat the price and convenience (although the "convenience" part of that could see rough days ahead what with the Chinese New Year and coronavirus problems..) Stock up boys! :)

op-amps. comparators, tl431

From the grey market (aliexpress etc.):

resistor kit big bag of diodes capacitor selection ceramic and electrolytic, possilby film too. prototyping board hook up wire. dc-dc modules. "mini360" is hard to beat at 50c each. isolated dc-dc modules panel hardware connectors,switches,knobs,and indicators enclosures microcontroller mudules (arduino clones etc)

extra resistors and capacitors in your favourite sizes, buy a few hundered and get the volume discount. pin headers

currently there could be some delay on stuff from China.

Use a LM2596HV module ($1) followd by a capacitance multiplier. (if the ripple bothers you)

--
  Jasen.

Hi, George

There are some really cool Chinese kits with all kinds of sensors an Arduino Uno clone, motors, solderless breadboard, alpha LCD display and so on for less than $30, all in one plastic box the size of a book. Amazon has them. Arduino is a good way to prototype with chips that need SPI or I2C to configure them, many of the manufacturers supply code and it's dead simple to use with the free IDE.

For random jellybean parts I suggest diodes like 1N4148, BAT54 (smt), 1N5819. Transistors 2N4401/3, MPSA42, 2N7000, BSS84, AO3400, AO3401, or their SMT equivalents in the first few cases. A few regulators. LM324/358 op-amps. Some good op-amps like AD8676. Some rail-to-rail input/output op-amps, maybe a couple high voltage rail-to-rail in/out op-amps, some zero-drift op-amps. An instrumentation amplifier or two.

Don't go nuts on the more expensive stuff, chances are if you have a project going there will be one or more parts you'll need to buy even if it's some oddball resistor, so you're paying for the shipping anyway and you may as well use Digikey or Mouser as your stockroom. It really doesn't make sense to try to stock everything.

It's probably worthwhile to buy some resistor kits and ceramic capacitor kits and electrolytic capacitor kits maybe if you use them (I do).

Best regards, Spehro Pefhany

You know those people making thousands doing drop shipping - that's one of them.

go to the source:

Or try these alternatives at 30p each.

Or buy 10 for a discount

--
  Jasen.

IME there's not been much solder that hasn't been fine. Of course now is the one time I have some that isn't, but it was an almost freebie that came from somewhere I'd not normally buy this sort of thing from. It works fine with the iron set to 400C.

NT

I've heard nothing good about cheap Chinese bench psus, but not tried one myself.

Totally depends on what you're doing & what you've got. But a few with little or no mention so far...

Matrix board. Crude & dated, but handy for quick very small circuits.

Cardboard boxes. Next time you're going to chuck out electronic stuff, toss the pcb in the box. Saves so much ordering & waiting for the post time.

Storage containers MUST be burstproof. Don't be tempted to buy anything that isn't, no matter how good a deal it might seem to be.

The LM324 is full of problems but crazy cheap & still my most used opamp.

An LED on the end of nearly a foot of bellwire is very handy for seeing inside tight spaces. Speaker wire to connect it to the psu.

Hoard a boxful of wallwarts. They'll be useful. Always rubber band the lead round the body, you'll regret not doing in the end.

Testgear is another subject.

NT

Yup. It's especially good for repairs and working with old parts because it chews right through the oxide without leaving corrosive residue.

Cheers

Phil Hobbs

snipped-for-privacy@gmail.com wrote in news: snipped-for-privacy@googlegroups.com:

I had/have (in my Boss's garage) a box full of kester 44 and other. Even silver based and a couple other non-lead alloys. Various flux.

I like flux pens too. Especially for new proto builds. No need for paste. Just wipe 8 pads with the pen and put a teeny tiny drop of solder on your hot tip end, and then hold the part in place with good strong tweezers and hit the pad and the pin/leg and the trip/drop at the same time to lock the part leg down, then do the diagonal opposite corner. Check placement and teeny drop the remaining pins/legs. On teeny bga or castle pin edges, one can add teeny drops to each ball or pad and reflow the part in place with a spot heater. Flux pens are cool, just do not soak the thing. Keep it about a tiny bit more 'moist' than a magic marker is. Unless you intend on full bath cleaning, that is. Then you can get that pen sopping wet and your board too.

Yuck, perf board--my least favourite method of prototyping.

Perf board is super slow, as you say, but worse than that, the protos are flaky and the grounds are always iffy.

Dead bug rules--it's very fast and produces robust protos, with excellent signal integrity as a bonus. Shorts are avoided by using the bodies of resistors and capacitors to keep the wires apart. I always gouge a notch into the pin 1 end of the package with dikes--that way I don't make wiring errors.

The dead-bug proto I posted upthread is a triple power supply plus two-phase lock-in amplifier that I used in the transcutaneous blood glucose POC that I talked about here a few weeks ago.

I posted a more polished version of that story at (Third entry down).

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

A box full of scrap boards. Many's the time I've lifted a part from an old board rather than wait for next-day delivery.

--
Cheers 
Clive

Thanks Phil.. I nice list. I'm not going heavy into parts, cause the whole idea could crash and burn if the photon flux from the DL's is less than I measured before... (or I made a mistake before, most likely)

George H.

channel into ~1" wide pieces and put a couple of BNC bulkhead connectors on them to make a poor-man's version of the $80 Pomona 2399 boxes.

e filter, DC block, attenuator, etc, for measurements.

Ohh! I like it! (U channel for boxes.) With another three sided 'box' as cover. Kind like old Bud boxes, but more robust. I've thought about making my own 'pomona' boxes by hogging out a block of Al... but that is a five sided box..

George H.

und lugs. I still giggle with joy at how wonderful this is when I use it.

cables, but I found that those 3D sculptures are so much less reliable. (Es pecially on a cluttered bench where you need to keep the untrimmed resistor /capacitor leads from finding other things to contact.)

Oh.. thanks Joerg Re: Through hole. I like to do air wires over copper clad.. like Phil's dead bug below. That way I see the whole circuit. (I always get lost flipping things over and looking fro mthe other side.. :^)

George H.

Thanks Clifford. I don't like those PCB's with grids of holes for prototyping.. (i get lost flipping it over.) I still will use my white proto push board to test some simple (slow) thing.

George H.

Thanks Speff, I do have an old arduino kit or two, I got for my some a few years ago..

Yeah I've become less of a tant. cap fan over the years.

George h.