Here’s some damage to a 1-week old Epever Tracer 4210AN MPPT Charge Controller, where some of the power FETs have decided they’ve had enough of this world. These are Alpha & Omega AON6512 N-Channel Enhancement devices, rated at 30V 150A. From probing around, these seem to be on the battery
Continue readingEpever Tracer 4210AN MPPT Charge Controller MOSFET Repair
Now it’s time to dig into the main contactor pack from the hybrid battery I tore down in a previous post. This unit contains the main output relays, precharge components, current measurement & protection. It’s pretty heavy, which isn’t surprising when you realise how much copper there is in this
Continue readingBMW Series 5 Hybrid Battery Contactor Pack Teardown
Here’s something I didn’t think I’d be doing! Here’s a teardown of a BMW 5 Series G30 530E Hybrid Battery pack – a monster 351V, 9.2kWh Lithium pack, obtained for it’s cells to replace the boat’s aging lead acids. This is something I didn’t have the safety gear to do
These days USB powerbanks are very common – ranging in capacity from about 1Ah, to about 20Ah. Internally, they’ve all got much the same format: Lithium Ion cylindrical or Lithium polymer pouch cells for energy storage DC-DC boost converter Microcontroller & LED Battery Gauge Display Lithium cell protection & charge
IPL hair removal is rather similar to laser hair removal – high energy photons are directed into the hair follicle to heat the cells up until death occurs, stopping the hair from growing. These units use high-energy Xenon flash tubes to do the job, and operate in exactly the same
Continue readingIPL (Intense Pulsed Light) Hair Removal Device Internals
My refrigerant leak detector has one flaw – from the factory it uses C-size alkaline cells. Considering I don’t normally stock these (nothing else I have uses them!), and they’re big & heavy, I decided to do a modification to run the unit from lithium cells instead. This would allow
Continue readingHLD-100+ Refrigerant Leak Detector Lithium Battery Mod
It occurred to me the other day that I’ve been running this blog now for over 10 years! This is the second iteration, as the first was lost in a server crash shortly after it went live. (Wasn’t so good with backups back then!). In that time the traffic to
Since I do a lot of camping, and several festivals per year (when there isn’t a pandemic on!), I identified the need for a proper fridge that can be powered from my solar setup. Such fridges & coolers already exist, that run from either mains AC, 12/24v DC, and some
Continue readingUndercounter Fridge – Conversion for 12 Volt Use
Just a quick teardown this month! This is an industrial RS-232/RS-485 to Ethernet serial converter.Not much to say about the outside of the unit, there’s the DB-9 connector for the 232 interface, and Phoenix connector blocks for the 422/485 interface. The main power input, and the Ethernet jack are on
On the front of the head is the filter carousel. In this case it’s only fitted with a 2.5mm Aluminium filter. These are used to filter out the low-energy X-Rays from the beam, reducing the overall dose to the patient of radiation that does not contribute to the resulting image,
A while back I found myself in the need of an adjustable RF attenuator capable of high-GHz operation. As luck would have it I had an old Spectrum analyser on the shelf at work, which we had retired quite some time ago. Spectrum analysers being quite capable test instruments, I
Continue readingTest Equipment Upcycling – Variable Attenuator Module
Recently I found the need to do some measurements on 75Ω CATV equipment, only having 50Ω test equipment to use. For this, matching networks exist to convert 50Ω to 75Ω, but they’re fairly simple, so building them was a viable option. Above is the very simple schematic to create the
There’s a common problem with all Software Defined Radios – their input stage is wide open, and therefore susceptible to desensitisation by local high power transmitters. The main culprits are broadcasts in the FM band, from 88-108MHz. Commercial stopband filters are available to solve this issue, by cutting out the
There’s quite a nice desktop app for the new NanoVNA v2, NanoVNA-Qt. It’s released as an AppImage for Linux, but unfortunately there is no version to run on a Pi supplied. The version below is built to run on the latest version of Raspbian (as of writing this, 2020-05-27). Enjoy!
Since I inherited an old HP 8753C Network Analyser from work, I figured updating a few things to relatively modern standards would be good. The factory CRT, being 28 years old, is definitely getting a little tired, not to mention being slow to warm up. I read over on the
This enormous box is the S-Parameter Test Set from a HP 8753C 3GHz network analyser. This unit contains the required components to automate the testing process for items such as cables, antennas & RF networks. The main EUT test ports are APC-7mm type connectors – a very expensive genderless RF
Continue readingHP 85046A 3GHz S-Parameter Test Set Teardown
Since I fitted the new “8kW” diesel heater to the camping power trolley, it has occurred to me that there is a lot of energy in the exhaust gas stream that ordinarily would be wasted into the atmosphere. Since we’re all still on lockdown here in the UK, I figured
Continue readingCovid-19 Lockdown Projects – Extracting Diesel Heater Exhaust Waste Heat
Since rebuilding the burner for the Webasto water heater on board nb Tanya Louise, I figured it was about time I sorted the exhaust out as well. The standard Eberspacher / Webasto type exhaust system components are shit. Nothing is properly gas tight, no matter how you build the system,
Continue readingNarrowboating Quickies – Webasto Heater Exhaust Rehash
Since the entire country is on Coronavirus lockdown at the moment, I figured it was time to get round to finishing off a couple of small blog posts while waiting for the restrictions to be lifted 😉 This is a small two-stage linear amplifier module available on eBay fairly cheap
Continue readingCovid-19 Lockdown Experiments – eBay 1-1000MHz 3W Wideband Amplifier Power Test
Time for another projector! This one was brought to me with a fault, described as a shadow in the middle of the image, shortly after the lamp was replaced after exploding. This is an older DLP projector, with a UHP mercury lamp. I’ve already removed the top cover of the
I figured it was about time I added to the medical kit, and since Contec, who makes my SPO² meter seems to have a decent level of manufacturing quality, one of their ECG machines seemed like a good choice. This is the ECG80A handheld Electrocardiograph. This is a single channel,
It recently became rather obvious there was something amiss with the water heater on board nb Tanya Louise – lots of smoke from the exhaust, failed starts, and finally a total refusal to start altogether. On disassembly, it was clear the burner was the issue – above. The mesh at
Continue readingWebasto Thermo Top C Burner Mesh Replacement
eBay yet again doesn’t disappoint when it comes to fake kit. Here is a claimed dual-band antenna, a Nagoya NA-771. This is supposed to be good for both 144MHz & 433MHz. The first clue is in the logo printing on the base, it’s not straight, or even. The base isn’t
Yet another wonder of Chinese mass-production, this is a cheap (£10 shipped) oil/fuel transfer pump from eBay. Primarily intended for removing oil from engines through the dipstick tube, these are usually sold for all kinds of pumping uses. As will become clear, pumping highly flammable liquids with these might just
Another Chinese eBay teardown! This is a “720p” LED projector, available from nearly everywhere for very little cash. But they are very little cash for a reason – they’re total shit. The resolution as stated is a blantant lie – the LCD panel used in these is usually around 320×240,