-
I wanted a reliable way to measure the true capacity of any rechargeable battery, rather than relying solely on manufacturer specifications. The most accurate way to do this is to fully discharge a cell under controlled conditions and measure how much energy it can actually deliver. To achieve that, I decided to design and build
-
This quick little project lets you send data from your PC to your raspberry pi, over a laser! We will however need a few components that may not be in our usual junk-box. So let’s take a quick look at these, and discuss which of their parameters are important to our project. First up, we
-
This is a quick description of how to get a bootloader onto a blank STM32F103 (bluepill) using the Raspberry Pi 3 Preparing the Raspberry Pi 3 Install the stm32flash utility: Next move the high performance UART from the Bluetooth device to the GPIO pins by editing /boot/config.txt Add the following line to the file: dtoverlay=pi3-miniuart-bt Next
-
The pulse-width-modulated output of an arduino is often used in conjunction with a small piezo-electric speaker to create tones and music. This simple approach works well; but if you try to scale up this approach and use a larger speaker, you’ll find the power output of the digital IO pin is not sufficient to drive it properly. To drive a
-
In my previous post I discussed my build of the slayer exciter Tesla coil and provided a few tips to make the circuit a little more robust. This post is a follow-up with a more advanced and much more powerful version of the slayer exciter. This circuit attempts to address a couple of the issues
-
Building a Tesla coil feels almost like a rite of passage. Certainly my life didn’t feel entirely complete until I built one for myself. I’ve heard this project can be a little frustrating, and indeed it was. You should consider yourself fore-warned; if you undertake this project you are very likely to blow up quite
-
Like most dangerous activities, playing with high voltage is a lot of fun. Sadly, I only have access to a measly 30V from my lab PSU. How can I go from this pitiful voltage up to a more substantive tens-of-thousands of volts one may ask? Well, one of the easiest way is to make use
-
I was looking for an adjustable oscillator that I could use as a frequency source for my Tesla coil. I already knew that the coil resonates at approximately 2 MHz, since I had previously built a Slayer-exciter circuit and measured its operating frequency. A common first choice for a simple oscillator is the 555 timer.
-
In the past few weeks I’ve been interested in the history of amplifiers and radio. The first amplifiers used only requires only a single amplification device and are known as Class A amplifiers. Class A amplifiers were popular in the early days because vacuum tubes were expensive and prone to blowing. The less of them you used,
An Easy, Battery-Free Guitar Input for Your SoundcardJanuary 13, 2026
A very low cost GaN charger for your bench.January 17, 2026
A Simple Arduino Metal DetectorFebruary 14, 2019
A Beginner's Two-Component Crystal-Style Wi-Fi DetectorDecember 12, 2025
Building Your First Tesla Coil: Tips and TricksFebruary 20, 2017
Discrete 32.768kHz crystal oscillator: Attempt 2.November 28, 2025
Silicon Junction 