Capacitive Battery Charger

Let’s start with the disclaimer. What follows is a Bad Idea, you could get blinded, burned, electrocuted or have your house burn down. This is not an exhaustive list. Really, I can’t recommend you try this yourself. The upside is a potential big saving in rechargeable batteries that you’d normally toss in the recycling.

Fake TV Security Light

This gadget steps up the game from leaving a light on at home when you’re out. Place it near a window to make it look like somebody’s at home watching TV.

DigiSpark With 64-bit Ubuntu

DigiSpark is one of the cutest Arduino-related widgets around. It’s about the size of a postage stamp, plugs straight into your USB port and will probably cover most of your microcontroller project needs. The problem is that it doesn’t seem to play nice, out-of-the-box with 64-bit Ubuntu Linux.

Programming Ramp Output on Rigol DP832

This is just a quick note to help those who might have trouble interpreting the instructions from Rigol for their awesome DP832 Programmable Power Supply Unit in order to get a ramp voltage.

Hacking Cheap eBay IP Camera

I bought a €40 “Anbere” brand IP camera from eBay to find that it can only be used to feed the supplied Microsoft Windows application. I need it to perform the simple task of serving a JPG through its web interface. This left me with two options: bin it or reverse engineer this shonky POS.… Read More »

Arduino FM Radio

10 years ago I bought a radio for my workshop. The criteria were: FM, cheap and mains-powered. I forgot to add the criterion: works. The radio was really bad at tuning – be that finding a station or keeping tuned to it. So I decided to gut it and put my own circuit inside.

A Signal Amplifier Module For HF

In building QRP HF radios, having an RF signal level amplifier building block is handy. You want 50 Ohm output impedance, some reasonable gain, supply voltage of the usual 10-14V and ease of building using standard parts from your parts bin. Some searching around the interwebs came up with a good idea for circuit from… Read More »

Downloading QST Magazine In PDF Format

I don’t do Microsoft Windows. Android and Linux are My Things. I subscribe to ARRL to get the digital version of their excellent QST magazine. Unfortunately, their support for offline reading in Linux is zero and their Android app is so poor as to be unusable. So I want to download QST in PDF so… Read More »

Clearing A favicon.ico From FireFox’s Cache

You know the problem – you’re a web developer and you’ve changed the favicon but can’t see the darned change, whatever you do. At the time of writing (spring 2015), version 36 of Firefox still needs to you to jump through a whole bunch of hoops to make this happen. I’ve seen a few recipes… Read More »