Steve's Things

Now, for those of you who don’t know me, I’m a total cheapskate. I hate paying good money for good things and wind up buying lots of crap for lots of money. Over the years I’ve seen the question asked by fledgling electronics buffs ,”What should I get to outfit my lab?”

Now this innocuous question is usually asked by people who either don’t have money or are cheapskates like me. I have purchased all kinds of cheap and slightly-less-cheap stuff from a variety of sources over the years and I’ve seen the quality and lack thereof. I’ve worked with it and I’ve had my problems with it. What I figure might be informative is a general guideline of some things I’ve bought over the years, especially the cheap shit, also my opinions on this stuff for people who are starting out.

It should be stated that I’m no expert on electronics and perhaps that makes my opinion suitable for the new hobbyist like myself. Sometimes acceptable is good enough.

The Multimeter

Every hobbyist needs a multimeter. They tell you voltages, resistances, current and often times things like frequency, diode voltage drop,  continuity and various other things. This will be your most important tool when things don’t work as they should or when building a circuit.

The cheap chinese multimeter

Above is the cheap chinese multimeter. They come in various colors and designs and you can pick them up sometimes for $5. While they seem like a good deal, they are not. I have had a great many of these and they have all been a problem in one way or another. Either the voltage shown is wrong, or the fuse inside is pre-blown or sometimes certain functions simply don’t work. If you just want one around your house to check to see if something is live, buy one but otherwise I would stay away. Now for the hobbyist, there is the middle of the road multimeter, these are the ones I would get if you want a blend of quality and cost effectiveness. Some brands to consider are :

• Agilent ($99 to $150)
• Extech ($50 to $100)
• Uni-T ($35-$100) meh..

There are others but those are the ones I have experience with. Obviously the more money you spend, typically the better product you’re going to get. If you’re gonna cheap out on anything in your lab, don’t cheap out on your multimeter, it is the single most important tool in your lab. Remember to get one that’s auto-ranging and don’t bother with ones that aren’t auto ranging or have those transistor testers on them. Transistor testers are the mark of a shitty multimeter.

The Power Supply

Whenever you do electronics work you need some source of power. This can range from using the USB port on your computer (like with an Arduino) to getting fully programmable supplies.

From a diy site on a refitted computer power supply

Some people try to save a few bucks and use a computer power supply for their projects. This isn’t bad since it outputs a whole lot of different voltages (3.3v, 5v, 12v, -12v) and can usually supply a whole lot of current. Only problem I have with them is the fact that they don’t tell you much about how much juice you’re using and you can’t limit the current.

Some people are really cheap and use wall-warts (like I did) for power. This is almost universally a bad idea because wall warts can fail spectacularly when shorted out or exposed to weird power loads. If you value your time and parts, don’t experiment this way.

A regulated DC power supply. This is basically the standard model made in china and is marketed under like 30 different brand names.

The best way that’s cheap is simply an analog adjustable power supply. They go for about 110 to 140 bucks and will last you a long time under normal use. You can adjust both maximum voltage AND maximum current so you can perform various tasks with it and save yourself headaches sometimes by limiting current. Trust me on this, for most things this is the best option.

Oscilloscope

Everyone wants to be able to diagnose problems with their circuits, see if there is actually changes going on over data lines, or see if there’s noise on your power supply or something. Also it just looks cool to have a 50’s mad scientist’s lab for when people come over.

This is one item that I see people cheaping out on all the time, and frankly myself as well. While I don’t have top end equipment at the moment, I have second hand equipment that is pretty good.

Your basic analog scope

Above is your general, all purpose analog scope. For most things this guy will serve you well. Buying a new one is often almost as expensive as buying a digital storage scope so buying one like this should be second hand. You can get an analog scope for a song on EBay sometimes and even around town at universities and college, they have extras kicking around. Using an analog scope correctly is a good skill to have and will serve you well with your digital storage scope, if you decide to get one.

a Digital Storage osciloscope

These may be your ticket to have in your lab. Some companies like tequipment sell GW Instek oscilloscopes for $300 or so. While it can be a bit of an investment, this may be your ticket to having decent equipment for your hobbyist lair. The one shown above is obviously an older one and similar to my tektronix 100mhz scope. I got mine second hand for $400 and it’s been a great investment. To be fair, there are other economy brands such as OWON, Rigol and others but I only have experience with the instek ones.

An example of the DSO Nano

The DSO Nano. They are cheap and tempting but they are not worth the money. From what I can tell, they have very low bandwidth and aren’t that great. There is a new model out for about 180 bucks, I may buy one to see what it’s all about. There are other portable DSOs out there but anything that’s any good is a fair amount of money such as the Fluke 123 and various others. OWON makes one for about $500 I believe.

An example of a usb oscilloscope

Well, some people like Dave from EEVBlog warn people away from these USB oscilloscopes but I wonder why sometimes. The only difference really is that the display is now standard hardware instead of the company having to engineer a whole interface on custom hardware. It should be noted though to stay away from the cheap ones on EBay. The ones for about 60 bucks have a bandwidth in the low KHz, yes, not MHz and they suck. Stay away from cheap USB oscilloscopes. somebody who appears to make good ones is Picotech, but that said they are the only company I have experience in that regard.

Anyways, You can get away with $300 oscilloscopes for hobby work, don’t cheap out if you can help it. It’ll make your life easier.

The Rest

Well, I don’t know if I can say “The rest”. there are so many things you can buy to accompany your lab that it’d take many tens of pages of writing to cover even in a very cursory fashion.

I’ll list a few things in point form you could need in your lab to make it both workable  and useful.

• Breadboards – Cheap and effective, get at least 2. You can get them for 5 bucks each on EBay
• Soldering iron – Spend 100 dollars and get a temperature controlled one. Weller or Hakko. Those cheap 20 watt soldering irons suck and you’ll waste more time than anything with them.
• Side nips, you can get these for like 3 dollars.
• Wire strippers – Again, EBay, Cheap. Get the lower gage ones 20-30 gage unless you do a lot of speaker wire and power stuff.
• Wire – get some rolls of solid core wire in both 22 and 24 gage. get different colors. red, black, green and white are recommended. more colors the better.
• Resistors – you can get sets of resistors off EBay or from Jameco for cheap. Get 1/4 watt ones, that’s standard.
• Diodes – a pack of diodes off ebay might cost you upwards of 2 dollars. yes. cheap
• component packs – These carry a whole slew of random parts you might need. Everything from switches and caps to potentiometers and other goodies.
• Alligator Clips – Get some alligator clip wires, very handy for everything.
• A good light – Get yourself some adequate lighting, only costs a few bucks but makes working much more pleasant.
• Arduino – Personally, I hate arduinos but if you’re new to things, get one. It introduces things in a much more pleasant way and allows results quicker.

The DON’T List

It should be said that I started out with damn near nothing but a bench and a $10 multimeter. I struggled and struggled and bought nothing but cheap crap because I’m a cheapskate. I didn’t buy a compiler and there was no such thing as an Arduino (At least not to my knowledge) so I wrote all my programs in assembly which is extremely time consuming.

Anyways, I suppose what I’m trying to say is that if I can learn it, anyone can. even on a limited budget. If you’re serious about it though, spend the extra few bucks and get something decent.