Macro photos of silicon wafers

Silicon wafer with three PC88 radio valves

Thanks to the wonders of eBay I now own three silicon wafers of some description, and because they contain microscopic detail I decided it’d be good to photograph them.

Focusing the camera was really hard, it’s bad enough getting a manual lens to focus but when the thing being photographed is so small it can’t be seen with the naked eye it requires a lot of trial and error. I also bought some old radio valves for a few quid off eBay too and decided to compare the two. It’s fun holding an entire wafer of ICs in one hand and having a single valve in the other.

Here is one of the wafers with some circuitry laid down in a regular pattern. The eBay bid says it was Intel memory of some description, but the wafer contains no visible writing to identify it. If I had a microscope I’d probably find something to read that’d identify it. The chips are arranged into small squares varying between half a centimetre and less than two millimetres across. I really like the edges of the wafers where there are half complete circuits due to the shape of the wafer. If these were processors, each one would be worth a hundred pounds or so, and the edge contains about 100 defective half made ones. A lot of the middle ones probably didn’t work properly either.

It’s hard to appreciate just how small the traces are on the surface, fortunately one of my hairs fell out while trying to get my camera to behave and I took a photo of it on the surface of the silicon wafer.

GPO 746 Rotary Dial Phone – Remember these?

UK GPO 746 Rotary Dial Telephone

When I was small I have memories of my grandma and my parents owning one of these phones, not that they had much choice of course since it wasn’t until the early 80s that other companies were allowed to make phones in the UK; before that it was the good old GPO’s job to rent one out to you. I took mine to bits to fix the dial, it kept sticking, and while taking it apart I took some photos which are attached to links throughout this post. Read on, this is more than a bunch of photos…
Continue reading GPO 746 Rotary Dial Phone – Remember these?

Lepai Tripath TA2020 Amplifier teardown

Lepai Tripath TA2020 amplifier I bought off eBay for $20
Lepai Tripath TA2020 amplifier I bought off eBay for $20

So, following the death of my ancient FAL Phase 44 amplifier, I found a series of very cheap amplifiers on eBay. They’re all based around something called a “Class-T” amplifier IC which seems to be an all in one IC that just needs hooking up to some inputs, speakers and electricity to work.

Click the image to look at the photos, or hit the “More…” link to continue reading…

Continue reading Lepai Tripath TA2020 Amplifier teardown

British Gas EnergySmart Energy Meter teardown

The British Gas EnergySmart energy meter
The British Gas EnergySmart energy meter

This box is known as the “British Gas EnergySmart” energy meter, and is available free to British Gas customers who sign up to their EnergySmart pricing plan. It’s called EnergySmart because instead of paying someone to come and read my meter, it’s now my job to crawl behind the telly every month. If I forget I get an estimated bill, which is bad.

See, that’s smart that is.

What’s even smarter is taking one of these things apart 🙂 Like the nice man on the EEV Blog says – “Don’t turn it on, take it apart!”. Continue reading British Gas EnergySmart Energy Meter teardown

Attempting to repair my FAL Phase 44 amplifier

FAL Phase 44 Amplifier
FAL Phase 44 Amplifier

Sometime last year my old Kenwood hifi amp stopped working due to the speaker cutout relays not working. The speakers would never switch on, making for a fairly useless amplifier.

While my cousin was sorting out his mess before moving to the US he found this old “FAL” brand amplifier. A spot of Googling reveals this was made by a company called “Futuristic Audio Limited” who also seem to make guitar amps. He didn’t want it, I needed an amp, so it came home with me.

Due to its age I noticed quite a lot of noise when trying to adjust the volume so decided today to take it apart and attempt to clean the insides out. I also bought some switch cleaner to spray in the potentiometers.

The insides were very simple. Here is a photo of the main circuitboard which contains nothing but through-hole mounted resistors and capacitors. The most complex electronic components in this are the four transistors bolted to a piece of metal. There are also some large looking capacitors, and an interesting looking network of diodes.

Unfortunately I think cleaning the contacts on the potentiometers and switches might have messed the electrical characteristics of the amp up. Since this isn’t an IC based amp, I have a feeling there’s a fine balance between the components that makes the thing work, and squirting a load of switch cleaner into things has altered this. When I power the amp up, only the left channel works and the volume goes really loud then distorts – all by itself, without me moving the volume knob. I’ll leave it for a few hours to see if the cleaner evaporates off. It’s no great loss if it is broken, the reason I took it apart was because the sound wasn’t correct and the volume kept wandering between left and right speakers, so maybe it’s finally packed in.

Looking at the electronics inside, part of me wonders if it’s repairable.

How vacuum tubes were made

I found these fascinating videos showing how vacuum tubes used to be made.

You can find part 2 here.

And if you want to know how tubes work, here’s a series of videos explaining them

Electronics at work Part 1

Electronics at work Part 2

Diodes have two plates. Triodes have three. That’s why they’re called ‘diodes’… I never knew that before.


Here is my tree, it has a colour scheme of red! The star on the top is home made and consists of four 1.5volt batteries on a double circuit. Each circuit has two leds and three resistors. The whole thing is made out of fence wire and heat-shrink tubing. The main tree lights are LEDs also, but since there’s no way to remove the top bulb (without cutting it off) I couldn’t power the star from the same transformer.