Posts tagged ‘Hardware’

Lithium Battery Protection for Small Projects

Lithium cells haven’t become the predominant power source for mobile electronics without reason. Circuits for their—very necessary—protection are naturally plentiful as well.

One particular weak point of many protection schemes, however, is deep discharge protection. Common practice is to discharge LiPo/LiIon cells no further than 3 V to not risk permanent damage. Yet, most protection ICs cut off only at 2.5 V, and you thus have to rely on additional battery voltage monitoring.

A Better STM32F0 Prototyping Experience

This project started when I was particularly annoyed by existing development board options and cheap Chinese PCB prototyping services were starting to emerge. Thus, the path forward was clear, but let’s start with the problems I was trying to solve.

When I’m talking about ‘development boards’, I mean boards like the Teensy models, Feather variants or blue pill: a PCB based laid out around a microcontroller containing very little extra circuitry; a ‘least common denominator’ of typical projects using that MCU, if you will. Evaluation boards with more interesting circuitry are great to get used to a microcontroller and its peripherals but lie beyond the scope of this post.

Pb Power bank

In preparation for being off-grid for a few days, I quickly built this ‘power bank’ around a 12 V 7 Ah lead gel battery. The circuit is simply pushed onto the battery’s 6.3 mm contacts and provides 3 USB ports. Charging circuitry is not included but the battery terminals are still accessible anyway.

Quick and Dirty B–H Plots

While building solenoids, I needed a way to quickly judge the magnetic properties of some unknown steel. A simple analogue hall sensor IC works together with a controlled current source for the coil to drive a XY plotter (or oscilloscope in XY mode) and create simple B–H plots.

Philips PM 3265 Repair

This post was the first post of my first attempt at a blog (which was never published). Albeit I since re-wrote it completely, I decided to keep its original date, which consequently now predates the date this site went online.

I still like analogue scopes. Although the convenience of a digital scope’s features is hard to be matched, I still like to come back to the older world from time to time. Why? I have yet to meet a DSO which is as satisfying to operate as even a basic analogue scope. On a DSO, no matter the price point, you always notice there’s software handling your input, given the ever so slight lag. Not to mention the overall haptics; rotary encoders and rubber push buttons just don’t compare to the real deal.