Electronics Engineering: Show me your projects, circuits, parts and tools.

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PanzerKrieg13

Gawd
Joined
Jun 20, 2005
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So here is the deal. I've always been into electronics, from when I was a kid and I would help my dad "dumpster dive" and dissect electronics. As of a few months back, I'm attending ITT Tech working towards my Associates in Electronics Engineering.

I never really noticed this forum before, so I'm curious to see what kind of tools you all use to work on electronics? What stuff you have in your parts boxes. What equipment you use to design, build, repair, tweak, hack, etc.?

I'm also looking for ideas on circuits and projects. Do you use a breadboard/protoboard? Show me some breadboard circuits. Show me some schematics. Especially things that will help me learn electronics theory and how to make components work together to make a circuit... You get the idea.

I'd like to make this a thread for a sort of "one stop intro to electronics engineering", but hands on style. Put theory into practice and real world applications, and of course have some fun sniffing solder in the morning.
 
Ok, well here's my contribution.

Tools I have:
--Soldering iron (cheap dual-wattage one from RadioShack)
--Diagonal (wire) cutters
--Wire strippers
--Multiple-voltage wall wart (1A, 1.5V-12V)
--Breadboard with lots of jumper wires
--Breadboard PSU (plug wall wart into it, it provides 3.3 or 5V to the breadboard
--Parts box. a multiple-tray fishing tackle box is good for this
--Desoldering braid
--A computer with EagleCAD for schematics and board layout, AVRStudio for coding for AVR processors
--Multimeter
--USBtinyISP for programming AVR microcontrollers

Tools I want:
--Helping hands
--Oscilloscope
--Logic analyzer
--Many-drawer organizers (like this one)
--Bench power supply with (at least) two independent outputs. (that's actually on my project list--to take a couple of computer power supplies and modify them into a nice, high-current power supply)
--Function generator

Where I get parts: mouser, digikey, and scrounging from busted equipment. Computer power supplies seem to die quite often, are easy to take apart, and contain boatloads of good stuff. Big caps, rectifiers, high-current fast-recovery diodes, beefy transistors, heatsinks, transformers, ICs of various types...I usually don't bother with the real small stuff (resistors, small diodes, small caps) since they're really cheap to purchase new.

For someone starting out, here's what I would recommend:
1) A tool/parts box. My tackle box has served me well
2) A soldering iron (30W works for me), with solder and desoldering braid. Even if you only do stuff on breadboard, the soldering iron is great for scavenging.
3) Breadboard with plenty of jumper wires
4) A power supply that you can hook up to your breadboard.
5) A small pile of parts to get you going. When I was in college, the EE shop sold a kit used for all their classes. It included a good variety of resistors, some caps, some opamps, some logic gates, some small-signal transistors (NPN and PNP), some small-signal diodes. I would add some LEDs, and perhaps a (very) small speaker. A 555 timer is good as well. And some potentiometers, too (trim pots are fine for starting off).
6) Alligator-clip leads. You can never have too many. Ever. Get lots of different colors.

Keep in mind that electronics is a very broad field. You have everything from audio systems to microcontrollers to wireless to DSP to power systems to electromechanics, and they are all *very* different fields with plenty of depth. There's no way you'll learn everything (...even though I seem to be trying...).

For projects, I'd start with the very basics. Learn how a resistor divider works. Learn Ohm's law and Kirchhoff's law and how to use them. Learn how each type of basic component (resistor, capacitor, inductor, diode, transistors of various types) works. Then start learning how to combine different types of components. For example, here is a sequence of projects I would recommend:
1) simple resistor divider. Then start messing around with parallel resistors to get a feel for the effect.
2) Simple LED--just a resistor and an LED. Do the calcs to figure out what resistor to use. Vary the resistance to vary the brightness.
3) Control brightness of the LED using a transistor.
4) Put together a 555 timer circuit to blink the LED. Play around with the various values of resistor and capacitor to understand how they affect the blinking.
5) Build a headphone amp using a LM258 or something similar. Learn about positive and negative feedback, virtual grounds, etc.
6) Use the 555 timer plus a power transistor to create a PWM motor driver

There are plenty of tutorials on the web. A google search will turn up a large number of very easy-to-understand places to look.
 
Thanks to the above poster. I'd like to see more of just that. You gave me some ideas and useful tips I have not explored yet. While I have most of the tools you listed, I still need to work up a breadboard power supply and I also want a bench-top power supply. There are kits available for the breadboard power supply, I thought of picking one up. Or using a bench-top power supply to power breadboard projects, which I like because I can dial-in an exact voltage and current.

When I get paid, I'm thinking of picking up an Arduino and some other parts. From what I've read on the net, it's a cool and interesting way to learn electronics and build circuits. It seems to also work pretty well with a breadboard, but add's a little more than simply building flashing LED's.

Tools I'd like to get once I have the money and know-how to use them is a oscilloscope and a signal/function generator. Fluke makes a really nice hand-held type of oscilloscope but it's still upwards of $1,000 when I last checked. My D/C electronics class at ITT starts up on Monday and I'll have access to that kind of equipment, I can't wait.

I've also got a project box going, with a bunch of parts and components my dad gave me, some parts I picked up at Fry's and Radioshack, and even a huge grab bag from Jameco. I intend on picking up another parts box and some more grab bags.
 
I have a Fluke 89-IV, and I'm dying to get a newer 289. the 89-IV is no slouch, though. I also have a Fluke 339 clamp-on meter.

I finally won on eBay for an HP E3630A power supply. I just finished calibrating it, and it's wonderful. I'd previously used a Radio Shack 5A, 5V power supply (with remote sensing!) that I built when I was a teenager, plus a 12-volt supply I built around the same time using a 7812 linear regulator.

If you're just experimenting, you can find digital scopes for less than $300 if you shop used.
 
For test gear I've got an old HP portable meter, an HP 5334B universal counter, Tektronix 2230 (with a completely broken digital section). Plus of course a few cheapo meters, a selection of probes and breadboards, Hakko 936 for soldering, AVR and PIC programmers, a good selection of small hand tools (cutters and pliers) and tweezers. Looking to pick up a bench meter soon from eBay and maybe a bench PSU to replace my hacked AT power supply. I've got my eyes on the Rigol DS1052E as a replacement scope. It's not particularly fast, but apparently well built with a nice interface, and quite small. It can be had brand new for < $400.

As for parts - well my parts box(es) are a mess. Not well organized, lots of one-off spares I bought for specific projects and just generally poorly maintained. I usually end up designing stuff on paper/EDA, doing up a BOM and buying lots of spares, rather than doing lots of breadboarding, which kind of sucks, but these days digital parts are tough to prototype anyway, you practically need to get PCBs made. Grab some jellybean chips for fooling around though, some 2N7000, 2N3904, and 2N3906 transistors, maybe some higher power ones from the TIP series, a kit of standard resistors and capacitors, some 555s, maybe a selection of 74xx logic, maybe some opamps like LM741 or LM358, some LEDs and signal diodes like 1N4148, plus some rectifiers like 1N4004 for power. Maybe throw a couple AVRs in there with a programmer if you're wanting to get into micros.

Plenty of fun stuff out there. I find there are some good audio projects that will get you a taste of it, but well documented and fairly easy to get started in.
 
Here are some pics of my work area I have at home. I am in dire need of a more organized flat surface than the 2 desks I am currently using. This is my gaming and dabbling area.

This first picture is of my main soldering / lay out area/desk. The left drawers and upper half of the middle drawers contain the whole E15 resistor set ( 0 ohm, 0.5ohm to 22Meg 5%) The rest of the middle drawer contains most standard values of ceramic and mylar capacitors and assorted tantalum capacitors.
The drawers on the right contain mostly electrolytic capacitors and other assorted components.
My soldering iron of choice is a Metcal PS01, I highly recommend snagging something similar off Ebay. The gray drawers on the bottom right are from Ikea, I have another set, unpictured, below the other desk in the coming picture..
I just finished building the 2 little 15V regulated 200mA PSUs for a high speed MOSFET driver. 2 of the 4 total, MOSFET driver ICs (TC4421A and TC4422A) are mounted on little copper heatsinks.
img0005rc.jpg


The next image is my testing desk, the right side of an L shaped desk from Office max. Currently on this desk is the makings of an Induction heater. I had it functioning, but pulled the power stage apart to use the new higher powered MOSFET drive with the above mentioned components. On the far right is a 10KVA variac, bridge rectifier, and filter capacitance. Just to left is the tank circuit for the induction heater, 9 turns of 1/4 copper tubing, 2x Celem CHF3 capacitors. Just above is the half bridge of 1000V 50A IGBTs.
img0007o.jpg


Next we have the test equipment.
HP 3478 DMM
HP E3630A PSU
img0008c.jpg


Tektronics TDS 210 'scope.
img0009nght.jpg


The drawers on this desk contain just assorted components. Silicon, ferrite torroids, screws, ICs, sockets, etc.
img0010gz.jpg


The next picture is of my PLL control board for the induction heater. Using the LM324 it features: topleft of the IC counter clockwise: tank circuit over voltage, soft-start circuit (the little 1uf electrolytic cap), inverter over current (Using the black current transformer), Lowpass filter for the 4046 PLL chip found just above. The blue pots are used to adjust the inverter current limit and tank voltage limit. The 8pin dip on the top left is a clipper used to sample the inverter voltage and tank voltage to generate the phase difference for the PLL to lock onto. (The 2 18k resistors just haphazardly soldered on, are there becuase the designed frequency limit on the PLL was too low to match the tank resonance. I need to change out the timing capacitor to a smaller value, just haven't yet.)
img0011gv.jpg


The next picture is a new breadboarded addition to the PLL control board. I just threw this little circuit together using an LM393 to generate progammable deadtime (0 to 2us) into the MOSFET drive waveform using the pot. This is to eliminate some shoot through I had in the halfbridge inverter.
img0012qo.jpg


Things on my wish list are:
Function generator - Something like a HP 33120a
LCR meter - prefer bench top, haven't settled on anything yet.
Panavice circuit board holder

The next projects are (I have contracted parallelprojectitis):
400VDC 30A active PFC PSU for the induction heater.
True sinewave inverter, 2kw range.
Class D subwoofer amplifier, 500w or so.
Flashpumped laser, I have most of the components just need a rod.
CNC circuit board router
Precision voltage reference so I can calibrate my DMM and then the PSU.
Many case mod ideas that have not come to fruition...yet.

Mohonri has a lot of good points.
Old CRT monitors are another good place to get components, just be careful to make sure it is discharged. Stock up on mylar capacitors, 1-10W resistors, various transistors, bunches of little heat sinks, etc. The magnetic deflection choke is wound with litz wire and very much worth the effort to unwind it. The core from a choke out of a 21" Trinitron can be seen in the first picture, top left of the middle set of drawers.

I think that is long enough, for now.

Edit: had to explain the horrible flying resistors on the PLL control board.
 
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Now that is what I'm talking about. You have an awesome supply of stuff and some very cool toys. I'm hoping to have something that looks like your setup, soon. But yeah, a bit more organized. I need to get a desk and clean up our garage though, because I just don't have enough room in my apartment for that much stuff...
 
when it comes to old vacuum tube mounts or "large scale" nothing beats a sledge hammer and a blow torch......
 
PanzerKrieg13 said:
There are kits available for the breadboard power supply, I thought of picking one up. Or using a bench-top power supply to power breadboard projects, which I like because I can dial-in an exact voltage and current.
Click to expand...
You can also pick up a pre-assembled BB power supply on sparkfun for $15. Mine is actually one I designed myself and plan to market, but for a lot less money (like $5+shipping).
 
awesome, after looking at this thread, I talked to the head of our network infastructure ( I work for a local GSM cell company) and came away with a ton of sold-state boards, racks, and a ton of other stuff... It was all stuff from the conversion from TDMA to GSM. Its a ton of solid state stuff but i'll let you know about it
 
FalconSS said:
awesome, after looking at this thread, I talked to the head of our network infastructure ( I work for a local GSM cell company) and came away with a ton of sold-state boards, racks, and a ton of other stuff... It was all stuff from the conversion from TDMA to GSM. Its a ton of solid state stuff but i'll let you know about it
Click to expand...

Sounds cool, take some pictures... Speaking of which, I need to post up some pictures and take some more once I switch rooms, and have a room again to dedicate for computers, electronics, projects, etc....
 
FalconSS said:
awesome, after looking at this thread, I talked to the head of our network infastructure ( I work for a local GSM cell company) and came away with a ton of sold-state boards, racks, and a ton of other stuff... It was all stuff from the conversion from TDMA to GSM. Its a ton of solid state stuff but i'll let you know about it
Click to expand...
Pics or Shens! C'mon, we all want to see your haul...
 
will do after work... Im thinking of how im going to move the rack by myself...its 10' tall!
 
FalconSS said:
will do after work... Im thinking of how im going to move the rack by myself...its 10' tall!
Click to expand...

As in rackmount? Or as in a big ass 10' foot tall rack filled with stuff? You have peaked my interest...

As for me, I'm slowly building my parts boxes, but I need to pick up some equipment like the user in an earlier post. I need some benchtop equipment.

EDIT: Got my SparkFun order this morning, finally snagged an Arduino. And some more parts, but nothing else special. I found a local electronics surplus warehouse open during the week to the public. Needless to say I've already spent a few hundred with em. Soon they'll know me by name.
 
These are a taste, sorry about bad pics, taken with camara phone


Pics of the Rack





Pics of boards and other stuff... ( I can get about 20 of those boards )



 
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lol, Was actually going to do a lot of the research on these while I was at work today, but I have been swamped. the only thing I managed to figure out so far was the

Bel 2745B chip on the board --> HIGH FREQUENCY MAGNETICS T1/E1 Through Hole Transformer
Lucent BUS1066H chip - Started researching but got swamped... I will let you guys know what all I have a little later.

pic of put together cabinet (from google )

 
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I need an oscilloscope... that 2 channel digital one is niiiiiiiiiiiiiice. I miss the 8 channel digital scopes from back in school.

I have a bunch of breadboards, bunch of components, circuit board uC programmer, power supply and frequency generator. these are the basics for building and operating circuits..

for tweaking and tinkering I have a soldering iron, the usual components, and some wire strippers. those big wire strippers that strip and crimp and do all that stuff are junk ( http://www.sears.com/shc/s/p_10153_12605_SPM161861577P?keyword=wire+stripper ), get a small simple adjustable one ( http://www.sears.com/shc/s/p_10153_12605_00973528000P )
 
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