1202 ALARM

Another garden power tool converted to run on Parkside/Lidl 20v lithium-ion batteries. This is a nice brush cutter from Ozito which had seen good service on an allotment, but had a failed 18v battery pack. I took the same approach as with the Bosch conversion and gutted the cells out of the battery pack and attached a Parkside adaptor plate. Interestingly, of the 5 cells (18650) in the Ozito battery pack, 4 are serviceable and only 1 had failed, just the same as the laptop batteries. It is working well and I still have 2 adaptor plates from my last AliExpress order for more shenanigans.

A few months ago I bought a mini electric chainsaw from Lidl to cut up wood for the stove. Going by the reduced gas bills I think the chainsaw has almost paid for itself. The chainsaw uses the Parkside 20-volt lithium-ion batteries and I bought a 4Ah battery and charger to run it. Since then I have bought a couple of other Parkside gardening tools and a larger 8Ah battery which was on offer. In all I've spent about £60 on the batteries so I want to get maximum use out of them. Now over the last few years I've acquired free or for a couple of quid, several Bosch drills. These are the last of the tools that used NiCad battery packs. The big SDS hammer drill above came with two 24-volt NiCad battery packs, one completely dead and the other almost dead. I bought a couple of 18-volt NiCad packs to run this and a smaller Bosch drill and they have been really useful, especially last summer when I was working on improving the patio lean-to. So could the Bosch dr...

ELECTRONICS UPCYCLING FAQ CHECK OUT THE OTHER POSTS ON THIS BLOG FOR DETAILS ON REPAIRS AND UPGRADES GOING BACK OVER 10 YEARS - What's the story? I've been tinkering with circuits for over 40 years and have an MSc in microelectronics, and a few years ago realised I could combine this with saving the planet. Basically I'm Greta Thunberg with a soldering iron. - Saving the planet? Well every electronic item kept out of landfill reduces the amounts of dangerous 'forever chemicals', getting released into the environment. By repairing items or stripping out most of the reusable parts this reduces what ends up in landfill and ensures the components go into the correct recycling bins, such as hard plastic cases. - Don't the council do that? Up to a point, but information has emerged about huge amounts of European electronic waste being shipped to Africa and Asia where it continues to damage the environment and people's health, especially the women paid ...

These nice Sony headphones came in another batch of stuff from a kind Freegle user. One of the drivers (speakers) seemed to have burned out and the earmuffs were badly worn. I had a poke in the spares box labelled 'Speakers & Sounders (Small)' and found a pair of Sennheiser drivers that were the same size. The Sony ones were built into the headphone housing, but were easy to dismantle and the Sennheiser units fitted right in. It was just a matter of soldering the cables in and they were not only repaired, but upgraded. I measured the earmuffs to be 70mm and ordered replacements for $3 on AliExpress. The headphones are light and comfortable, but have the great Sennheiser sound quality. Job done.

I found this project while I was experimenting with the NTSC Color video generator some time ago, but finally got round to ordering the parts I needed recently. Thanks to Grant Searle for the awesome work on the project, which seems to have slipped into the recesses of the internet. This may be because unlike the classic 'TV_Out' for the Arduino, you need a programmer to upload the hex file directly to microcontroller. The circuit uses a 74HCT166 parallel in/serial out shift register, clocked at the same 16MHz as an ATmega328P microcontroller, giving the speed necessary for a 640x200 pixel display. The biggest problem I had was with the ATmega328P ICs I bought on Aliexpress. These seemed to have the option fuses set for a slow internal clock and it took a bit of messing about to get the fuses cleared so they could be set for the external crystal. Best of all, data is input via a standard I2C 2-wire interface which will connect to PIC microcontrollers (which I have ...

A kind Freegle user gave me a big collection of vintage home computer equipment a few months ago including 4 48K ZX Spectrums in various states. The photo above shows one of them connected via the aerial RF socket as a test. The random pattern is a typical ssymptom of failed memory ICs.  The first job was to examine the main boards in each of the 4 computers. 3 were Spectrum+ units in the bigger case with the better keyboard and 1 was the classic Spectrum with the rubber keyboard. Unfortunately the classic's case was in very poor condition, but 2 of the 4 main boards were suitable for restoration along with at least 2 of the Spectrum+ cases. The 7805 regulator is a linear type and generates a lot of waste heat, hence the big heatsink. These can be easily replaced with a high-efficiency TSR1-2450 swich-mode type so that the heatsink can be done away with. The next job is to modify the RF modulator to output composite video. This just r...