Electronics - Inverter repair

An inverter is a useful thing. It takes a stack of electrons from a 12 volt battery, and makes them look like the stuff that comes out of your wall, in my case at 240 volts.

How it does it is anyone's guess.

In my case it doesn't actually do that. In fact all it does, is take a stack of electrons from a 12 volt battery, and turn them into the smell of melting value.

I couldn't understand why a perfectly interesting looking device should fail.

Here it is pictured after it was repaired, but it also looked pretty much like that when it didn't work, but now I've given away the ending to this tale.

I fixed something - a first.

Note the total absence of left over bits - also a first.

Normally, the plan of attack is to open the device up, then put all the left over bits in the bin next to the now slightly more hollow, and slightly lighter device.

But this time was different.

To begin with I already knew why it was making all that melting plastic smell.

It was over heating.

The thing has a fan that is presumably meant to spin around a lot. At least I hope it's meant to spin around a lot. If it isn't meant to, it does now.

Perhaps I just invented something....

To make an artificial breeze, simply take a normal fan, and make it spin.


The point is the fan wasn't spinning. I have a few fans that I've pulled out of junked computers, so I figured I'd just replace it. I can solder a bit now as well, so I figured it should be easy.

There were even some obvious screws to undo.

I used the electric screwdriver my mum bought me as part of a present.

Thanks mums everywhere. It even has a torch built in and you can never own enough torches, even when you will never use them.

I always thought electric screwdrivers were a bit pointless, but it turns out they are excellent. I've just never actually needed one before.

Unlike this project, my last had a few bits left over, and this was where the electric driver was really useful. It turns out there are a zillion screws inside stuff.

Pictured is all the leftover bits not including all the gears and shafts and all kinds of springs and stuff that might come in handy one day.

"What are the chances of any of it coming in handy?", I hear you ask.

But that's what they said about the 200 short lengths of black poly irrigation pipe I still have in the shed.

This thing used to be one of those fax, copier, printer combo devices that wasn't working any more. A friend was throwing it away, and thought my car was as good a place as any to throw it. It turns out there are some good motors and gears inside. I think there were five motors in there. That's them on the right. Maybe six motors. I'm planning on needing some motors, gears, and some shafts for making my solar tracking heliostat. There are also a stack of salvaged components used for tracking the placement of motors. The motor on the bottom right has a spoked arrangement that passes between a censor that detects light, and a light. The shadows cast by the spokes allow the system to track where the print head is. Or so I've read.

So much to learn. So much time. If you just stop watching TV.

Anyway, I've drifted off what pretends to be this post's topic...

Ok, so the fan wasn't spinning.

None of the fans I had would fit exactly, and would have to be trimmed (hacked and snapped with a pair of pliers) until they could be coaxed into duty.

I looked under that foil label and found the exposed end of the shaft.

I thought I'd drop in some oil before I replaced the fan to see if that's all it needed. It was.

The black, and off white cylinder in the front with the brown stain at the base is a capacitor.

I'm guessing it was also the source of the burnt plastic smell.

So that had to go. Luckily I have stacks of different capacitors from pulling apart some stuff, and had a duplicate.

A big component with large nicely spaced pins that proved easy to solder.

The thing went back together with no left over bits, and no spilt coffee added.

I realise this was a very simple repair, but it is something I would have sent to landfill before learning a bit of electronics over these last few months.

Here is a terrible photo of it charging a phone through it's transformer, and maybe a bit of Bigfoot's leg. Who can tell.

A 12v car battery supplying an inverter outputting 240v, then through the iPhone transformer to bring it back down to 5v.

Ok it's slightly inefficient, but the phone was the smallest thing I could take to the car to test it.

I rate this a total success.

Which is nice.

120 Things in 20 years - Bringing me one step closer each day to being able to take down a Terminator. Or repair an inverter. I need to win a 3D printer.


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