Initializing Workshop

Are we mainly talking about electronic components?

To some extent it depends on what type of projects you want to do. Collecting a basic set of components is surprisingly annoying. There are also significant variations depending on what you want to do.

I recently put together a kit for a relative... and this was the logic I followed:

Breadboarding Stuff

This is all stuff that I would want as long as I was just doing experiments with a breadboard, standard components, and some form of microcontroller.

The absolute Basics

• Some kind of microcontroller - at least one arduino... even if it is only used for breadboard projects
• Breadboards - Note the plural, you'll want at least two for one project
• Simple Power Adaptors - The breadboard type that outputs 3.3V or 5V on a jumper works well
• Set of breadboard wires (spools of solid copper wire 24-26 gauge can be used here)
• A set of wires with small clips at each end... just handy for connecting things to the breadboard.

Basic Breadboardable Beans

Resistors

You will mostly want 10k, 1k, 100 ohm, and a selection of values from 220-560 for LED current limiting in quarter watt packages. Occasionally a 100k or 10 is useful.

I've also found it useful to have a high value and low value shunt in a high watt package (1 ohm and 500 ohm in 100W RX24 packages).

You will also want some potentiometers... generally a few 10k's are enough.

Remember that you can mix resistors together in parallel and serial to get more specific values.

Capacitors

The other major passive. Far and away the most commonly used here is the ceramic 100nF. Second is probably 47nF.

Capacitors is an area where I tend towards a wide but shallow selection. Although you can combine caps to get more specific values, caps have much wider tolerances than resistors and tolerance stacking can bite you here in all but the simplest compound capacitors. I somewhat frequently wire up simple RC circuits, if I didn't I would probably need less here.

At around 1uF, electrolytics typically take over from ceramics, but truly large value electrolytic capacitors get to be quite expensive... only buy these if you actually have a specific plan for them.

Diodes

Getting into our first non-linear component. Diodes are handy, but you typically don't need that many of them. For breadboarding, a pile of 1N4004s or similar is usually good enough.

LEDs

A selection of 5mm leds. Keep in mind that you don't really need very many of these. If you're going to do a big project like an LED cube, you'll special order those LEDs anyways.

Transistors/BJTs

This is always an awkward one. For basic timers, a handful each of 2N3904s and 2N3906s (or some other NPN/PNP pair) is probably enough. But if you need something more specific than that, you will generally need extremely specific Hfe characteristics for your particular application.

Most "BJT multi-packs" include a significant number of audio transistors that are a little finicky to use if the audio characteristics are not what you're looking for.

MOSFETs

I feel that the fact that most kits do not include a handful of logic level mosfets is a major weakness of most of these kits. MOSFETs have taken over from BJTs in many high-power applications for efficiency reasons. I always keep a handful of FQP30N06s/IRFZ44Ns and IRF9540Ns around.  (although the N-channel type is used significantly more often than the P-channel type)

The weakness of MOSFETs is that even "logic level" MOSFETS may not be fully conducting at logic voltages, particularly 3.3V.

Inductors

Because I play around with making my own boost and buck converters, I have a selection of inductors, but I don't particularly recommend picking this up until you decide this is something you want to do.

Simple User inputs

Switches/Buttons - At least a handful each of some kind of latching switch, and some kind of momentary switch

Encoders - For those times when you need infinite inputs... or just a knob + button in one.

As mentioned above, a few potentiometers.

ICs

Logic Chips (74series and CMOS series)

Setting aside arduino and other microcontrollers for the moment. If you want to experiment with 74-series or CMOS logic, you're going to run into the problem that professional engineers have been adding chips to this set for more than half a century. There are a lot of chips out there, and it will absolutely never fail that no matter how wide a selection you have, the chip you want will require a special order.

It also doesn't help that these are not particularly cheap.

I keep a largish number of SIPO and PISO chips, 74x595s, 74x4051s, 74x573s around... I also got a cheap CMOS multi-set, but have to admit I've only used two or three chips from it.

OpAmps

Operational Amplifiers are incredibly useful chips for fiddling around with electronics. The ability to "read" an electrical voltage while only sipping on the current is very useful. OpAmps have fairly extensive online "cookbooks" that show various configurations. Having at least one dual rail (positive and negative) OpAmp and one single rail (only positive voltages) OpAmp type on hand can be quite useful.

Timers

There is a meme in the online electronics community of someone showing a project they did with a microcontroller, and a somewhat snarky reply comes back that "you could do that with a 555 timer". Although it's important not be be rude to each other... it is also true that a tremendous number of timing-related projects are somewhat easier to implement with the venerable 555 timer. (or 556 dual timer)

Others

There is a deep and rapidly expanding world here... some that I use often are voltage references (typically 4.096V or programmable), external ADCs, DACs and PWM and signal generators.

Outputs

These are often straddling the line between "breadboard experiment" and "real project". But even if your experiment is staying on the breadboard, you may be looking for these types of things.

Motors

If you're going to drive anything, you're going to want motors. Steppers (ideally with drivers), DC motors (again, ideally with drivers, although a MOSFET and diode will work in a pinch), and servo motors. Exactly what you want here depends on the type of projects you want to pursue.

On a side note, motors are really easy to salvage out of things people throw away. High quality motors out of salvage is my favorite way of supplying myself here. Literally tons of motorized kids toys go the the dump because the terrible plastic gears snapped. Housewares with dead batteries send more tons of excellent 12V DC motors after them. Let your friends and relatives know that you have a hobby of "tearing broken things apart to see how they work", and you'll be surprised what people will just give you.

Lights and Lasers

LED strips, high power LEDs, and small laser diodes are all handy to have if you have any "illumination" projects. I've also had fun playing around with IR LEDs.

Speakers and Buzzers

Although I rarely play around with sound, having a few piezo buzzers on hand has been handy for some projects.

Displays

At least one simple LED display. I tend towards small, cheap, higher-resolution displays these days... but some form of outputing things.

Inputs

Buttons

I can't be the only one who collects interesting switches and buttons, right? At a basic level, you need instantaneous buttons and latching buttons.

Sensors

They sky is the limit here. Photo-resistors, Shock sensors, IR modules, temperature sensors, hall sensors, ultrasonic sensors. Bill has a lot of interesting videos on a lot of interesting sensors.

Radio

You can make simple radio-controlled sensor networks with microcontrollers. Pretty sure Bill has a video on that.

Making things real

Okay, so you've been experimenting on breadboards and gotten things working (with a few failures too), now you want to put projects somewhere other than your bench. You have a few new complications.

Breadboard Replacement

• PCB Prototyping Board
• Solder
• Soldering Iron
• More wire.... always more wire...

Power

Linear Power Regulators

I have a multi-pack for 5V-24V, plus a few extras... but have to admit that the only ones I use regularly are L7805 (5V), LM317 (Adjustable), and L78L33 (3.3V).

Buck/Boost Converters

Your basic buck and boost converters are quite efficient ways of handling battery power for most applications. It's worth having a few of these around even for bench work.

USB Connectors

To be honest, one of the easiest ways of powering small projects is to use a female USB connection and just use a wall-wart from from an old phone or any of the other dozen devices that use 5V off of USB today.

Controls

Relays/SolidStateRelays

Relays are occasionally useful when the voltages on the switched side are higher than you want to deal with via a mosfet or transistor. Be a little careful here, though, particularly if you are switching AC mains voltage with these. I personally prefer using SSRs, but they are quite a bit more expensive.

Connectors

JCX, Dupont, screw terminals... various ways of connecting outside wires to your PCBs

This should be pinned! Great post.

Indeed! Thank you so much for your detailed answer. Making my shopping list now...! 🙂

Have a nice weekend!

I have rather basic question on power plugs.  I work mostly with DC Motors 12-24V 3-8A.  All the stuff I see on ebay says they are for speakers and I'm not sure they can handle the maximum load of 24V @ 8A.

I'm finishing up a ATX power supply and would like to clean it up.  Any comments are appreciated.

Sal

@salp Do you mean RCA jacks, that's what I associate with speakers. If not a picture will help then it's just a matter of tracking down the specs.

What part of the ATX supply needs this? I am also building one and I am using banana plugs.

@ronalex4203   Yes I meant the banana plugs ( reference https://www.digikey.com/en/products/detail/mueller-electric-co/BU-P3760-4/7917559 ).

The post referenced above is sold by Digi-Key and others for $3.00+ each and then I see the ones advertised on ebay for something like a 10 pak for $3.00

I'm assuming the difference in pricing has to be due the current rating?

Ant thoughts?

Posted by: @ronalex4203

Do you mean RCA jacks, that's what I associate with speakers. If not a picture will help then it's just a matter of tracking down the specs.

Actually, RCA Jacks are used as low-level audio inputs. When you see them on speakers, it's because those are amplified speakers.  You'll also see them on receivers and amplifiers.

Many stand-alone speakers do indeed use Banana Plugs.  They are also used on test instruments.

Posted by: @salp

I'm assuming the difference in pricing has to be due the current rating?

If you look at the Spec Sheet for those plugs, they are rated at 15 amps.

These ones are rated at 30 amps, you can see them in the bottom right of the spec sheet. And they cost five dollars each.

I’d rather trust the Digi-Key parts for anything handling current, like a power supply. But if you were building something like a signal generator than the eBay ones are certainly more economical, and could possibly be just fine.  The key to determining that, of course, is to get the spec sheet for them, but that's often not possible with eBay sellers.

In your situation, I'd buy the best ones at Digi-Key for the power supply. But I'd also order a pack from eBay to keep in stock, at worse you're out two bucks, and you may have stumbled upon a bargain.

And with the worldwide shipping backlog, you'll get a nice surprise in the mailbox nine months from now when they get here!  If you're in the US or Canada, Digi-Key delivers the next day.  They, and Mouser, are my favorite "candy stores"!

😎

Bill