Comedy : The race to zero and why we should never be surprised by crap

I may have mentioned it a month ago, but to remind you, my invisible people, I ordered a quite well-researched cheapest multimeter from the far off lands, the price, including shipping, was just four dollars and seventy four cents of our Canadian money, I was curious, how bad could a multimeter that costs about the same as a deluxe coffee actually be?

I researched it, sort of, and ordered it, and waited...and waited....

It arrived, they mostly do, from the far off lands, and it weighed, well, it weighed very little. No ballast to make the thing seem real, but oddly, once a battery was inserted, which still made the thing appear to be lighter than air, the product seemed to do most things that it was supposed to do.

Most things.

No fuse, no beeps, very questionable triode detection. It was obvious when removing the back cover to place the nine volt battery that there was neither a fuse, nor a beeper unit and if you look at that ring of 8 holes for the transistor testing, well, you can understand why the three prongs of an NPN or PNP would have difficulty making contact all at the same time. However, to temper my rage I looked at the original listing and saw that neither a fuse or a buzzer were promised, the wording, the reviews, all pointed to the glaring fact that this was potentially a death trap that had no bells or whistles.

I know enough stuff about electrical things now to be dangerous, so looking at the above photo I can point out the shocking detail of the no fuse, where perhaps a fuse should be, so the question then would be, how would this little miracle react to bad things happening in the real world, and the answer perhaps does not require any training in rocket science.

The two main probe contacts, bottom left, well they are extremely close for potential arc points when high voltage AC or DC are applied and when installing the battery it actually pushes them closer, so there is one dangerous point of failure, another would be one of those many surface mount resistors, a mystical point of magic smoke when you jam one of the inadequate, poor quality, probes into an AC outlet. In essence, there is a fuse, just not one you can replace...

What do I know, what do I care, I cannot even buy a pint of beer any more for the price, and this little, lightweight, wonder can be used to check "little" things and can perhaps be used as a sacrificial multimeter when I do not wish to risk a higher price unit, after all, a replacement fuse on a good quality Fluke meter would probably cost twice what this little hampster costeded.

I will admit though, when I opened the package from the far off lands, my first reaction was to immediately send this to the e-waste depot, but you know, with a little time, you realise that you do get what you pay for, and if you pay next to nothing, you get next to nothing.  

I subsequently sold the little meter, I included it in a small toolbox of spare, useless, parts. It was interesting to hold and play with such a poor little multimeter, and in my research along the way, I have discovered that the terrible internals of this type of meter are sold in many different ways by our far off friends, perhaps it is in their interests to electrocute us all.

Ok, now I have rid my world of that sordid little thing, I should go and buy another....

Flip Flop LED breadboard

In the growing supply of kits I have waiting to hone my soldering skills, there are two very simple ones, they are what is called a "Flip Flop" circuit that utilizes two LEDs, two transisitors, two capacitors and four resistors. This is the circuit diagram :

There is a logic afoot within this circuit, and I will attempt to explain what it does, in simple terms it flashes two LED bulbs and most brainiacs will say that it is indeed a very simple circuit, but for me, it was a challenge to get my pea-sized brain around it all, mainly as you can buy flashing LEDs for pennies, however, flashing LEDs also make use of a miniature transistor circuit that is contained within the LED housing.

Here is my attempt at explaining, it might be wrong, but the idea is in my head and I may as well write it down so that in the future I can look back and scoff at how little I actually knew at this point in my education.

The circuit calls for two BC547 transistors which are NPN and the capacitors are connected to the base on each, think of the capacitors as little batteries that cycle from uncharged to charged and when "full" discharge and open the transistor switch so that the corresponding LED can receive current and lights, when the capacitor is discharged, the transistor base is not powered and that LED switches off. While all that is going on, the other capacitor has charged and then provides base current to the other transistor and the other LED lights, this backwards and forwards action continues, so the two LEDs flip flop.

Suitably vague?

I breadboarded the circuit using components out of my supplies, so the transistors used were ZN 2222A another NPN type and the capacitors were 10/35 which are 10 microfarad, as they say, who dares wins and I didn't have the correct components (a bit of a lie, I did, but they are part of the flip flop DIY kits I have purchased shown in the photo) anyhoo, that is what I used for the breadboard experiment.

The kit, shown on the left, will be the next step, cost was a dollar from the far off lands and I bought two, in case my big sausage fingers and soldering incompetence get the better of another set of components. The breadboard was set up and it was happy times as the flip flop worked with both 5V and 3.3V - as usual, I called my good lady out of her happy place and showed her my flashing lights and she said "That's nice dear" and went back to doing whatever she was doing before being summoned by her mad scientist spouse in his thousand year education towards building a hadron collidor.