Joy Comes in Bags From China

This week I decided to bite the bullet and go through the projects that come with the Radio Shack Electronics Lab Learning Kit. I bought one when Radio Shack closed a bunch of its stores last year. It’s kind of a neat tool for learning about electronics. Cheap, too.

The lab is basically a breadboard (six columns) with various things you can connect to the components. Built into the lab, there are switches, an analog meter, a buzzer, and other things that can be useful.

I think the best way to do this is to keep a lab notebook and do reports. As a former physics teaching assistant, I should have no problem with that. I have to make up experiments, though, because the stuff in the Learning Lab books isn’t written for people who collect data and do analysis. The writer, a well-known electronics teacher named Forrest Mims III, just wants people to build stuff, see if it works, and move on.

I decided to do things like changing component values and writing small tables. Then I can compare the results with the mathematical formulas associated with the circuits. Short and easy, except when ineptitude gets in the way.

Writing things down is very important when you do anything technical. I say that as a person who doesn’t do it. I have suffered the consequences.

This isn’t the only thing I’ve done to amp up my electronics game. I bought a bunch of cheap components on Ebay. This was a genius idea I should have had ten years ago.

When you build circuits, you’re always in need of this resistor or that capacitor, and if you don’t have them on hand, you have to drive to Radio Shack, drive to a different store, or order the parts online. My local Radio Shack, where I used to shop for parts when I built current and temperature controllers for a professor’s laser diodes, bit the dust in 2015. We have an incredible electronics supermarket in Miami, but it’s expensive and far away. Ordering online is fine, but if you did it for every part in a simple circuit, your build would take six months, and buying one part at a time anywhere is way expensive.

I found some guy selling 1% tolerance 1/4-watt metal film resistors for $15. How many? Which values? Try 2800! All values! Nearly. You get like half a pound of resistors in a huge number of values. I also found great deals on film caps, Chinese ceramic caps, and a few potentiometers in common values. For the heck of it, I picked up some IC’s and sockets. Can’t hurt.

Here’s the rub: the resistors have thin leads. This doesn’t bother me, because I would much rather have a thin lead than wait ten days for a resistor.

The resistors arrived today, and I decided to check one. I was suspicious of the 1% claim. I don’t need 1%; 10% will be fine and dandy. But you want to know what you bought.

I hooked a resistor to a meter and heated it with a soldering iron. The value was 430 ohms. The resistor measured exactly 430, which was way beyond any level of precision I’ll ever need, and it didn’t move when I heated it. SOLD!

Even if the resistors aren’t great, they’ll allow me to build things without waiting, and if I have to, I can get better stuff to replace them in permanent projects.

Caveat: some guy on the web says he scraped the paint off his cheap “film” resistors and found carbon resistors inside. Not that a 1/2-cent carbon resistor that works is a bad deal.

The soldering iron is also news. Twenty years ago, when I got my Weller soldering station, I thought I was the coolest kid in school. I was used to pencil irons that weighed a pound and had to be placed in cereal bowls because they didn’t have stands. I started looking into different irons this year, and I found out my Weller was strictly low-budget.

It turns out you can pay a thousand dollars for a soldering station, and they come with lots of crazy attachments. Also, cheap stations don’t have enough power. They take too long to melt solder, and this can actually screw up your joints.

I thought about getting a Hakko. They’re very popular. But I kept looking, and I found myself a dream come true: the Ersa I-Con Pico. Yes, it has THREE names.

Ersa is a snooty German company (what a rarity), and they make high-end soldering stuff. The station I got is like their Maverick or Vega (remember those?). Still, it’s way better than my Weller or a Hakko. It has a digital display. It pumps out about 80 watts. It gets hot in ten seconds. Best of all, it has a tiny iron a little bigger than a pen.

The general rule with cheap irons is that they’re too long and too heavy. There’s no reason for it, as far as I know. It’s just a fact of life. It can be very hard controlling a soldering tip four inches from your hand. The Ersa’s tip is like two inches from your fingers. Beautiful!

I think this is an example of having a lame tool you didn’t know was lame until you replaced it with something good.

I haven’t soldered anything yet. The package just got here. On Sunday. Amazon is starting to scare me with their newfangled speedy deliveries. I half expect to wake up and hear Jeff Bezos singing in the shower.

In summary:

1. you need a pile of cheap electronic components from Ebay;
2. you need a better soldering iron; and
3. you should really try an organized approach to learning about electronics.

I preach to myself.

One more tidbit: if you have a cheap multimeter and you want to kill yourself because the Chinese probes won’t hold onto anything, spring for some Fluke spring-loaded probes. I finally did. What a difference. I had cheap Chinese ones, and the plastic flaked off until they refused to hold anything. I could have cobbled a solution together, but I bought new probes, and now life is sweet.

I think I may sever the Chinese probes, toss the ends, and attach alligator clips.

With my new soldering iron.

Hmm…I think that might be “cobbling a solution together.”

BTW, I found out how you’re supposed to make shrink tubing contract. They sell miniature heat guns for the purpose. You can buy a fancy “rework station” that includes a heat gun. I think that’s a stupid move, because one part of any all-in-one tool will always break before the rest, and often it can’t be fixed. So there you would be, with your fancy station, a heat gun that doesn’t work, and another heat gun sitting beside it taking up space.

And the new heat gun wouldn’t match the station, which kills the fun of the whole all-in-one ethos.

A company called NTE makes a small heat gun that gets good reviews. I may get one. It’s about $20. I’m tired of roasting my shrink tubing with a lighter.

Hope this is helpful to you. Probably not, though.