I was slightly concerned about the contact resistance of the 10->8 mm brass compression fittings in my induction heaters tank circuit. Out of curiosity I measured the resistances in my tank circuit. I thought I’d make this small post about […]
I had the need to test the saturation current of some inductors I had wound. I built this pretty simple tester for testing the saturation current of inductors. It seems to work pretty well up to about 100A or so. […]
I’m currently building an induction heater. I’ve already built one controller based on an analog PLL so this time I decided to go all digital and use an ARM Cortex-M4 microcontroller (STM32F303). For this I needed to implement a digital […]
This is a project I made quite a while back (about 7 months ago). I wanted a bigger display for a project of mine and noticed that PlayStation Portable displays (480×272 pixels) are quite cheap on eBay but they do […]
I heard about the CERN Open Days on the eevblog forum. I managed to get some tickets for an underground tour to the ATLAS experiment so I decided that I just had to go and see CERN for myself. Me […]
I am currently building an FMCW radar. I do not have all the parts finished so I made a doppler radar from the parts I had on hand. Theory Basically a Doppler radar is a type of radar which measures speed […]
I recently saw a post on Hackaday about a course in MIT where the students get to build an FMCW radar from mainly off-the-shelf components. I got pretty excited about it and immediately thought that I wanted to build a better one from […]
I had some space left on a PCB panel I was ordering so I quickly whipped up a return loss meter based on an AD8319 logarithmic detector from Analog devices. The AD8319 is specified up to 10GHz. The circuit has a […]
I wanted to listen to HF bands using my RTLSDR USB dongle. Since the RTLSDR dongle can only receive from around 64MHz upwards I needed an up-converter which converts the HF band (0-50MHz) to a higher frequency I can receive […]
I recently ordered an EzTV666 USB DVB-T stick from eBay. People have found out you can use these sticks as Software Defined Radios (SDR) which can receive radio signals in a very wide range of frequencies. The particular model I got has RTL2832 chip […]
A few weeks ago I was on a junkyard that had a decent amount of telecommunications equipment. Mainly racks of old cellphone 3G (I think) basestations from which I got a load of some interesting RF stuff. I also found […]
Here’s a quick project I made in couple days or so. It is a push-pull step-down laser diode driver based on LT1683 SMPS controller chip from Linear Technology. The circuit works with 12-18V input and can put out about 1A to […]
I spent the whole yesterday battling with an ATMega16U4 microcontroller. I was trying to set the fuses to use the internal RC-oscillator instead of the external crystal oscillator. In the end I had to modify my avrdude.conf but the problem […]
I have added support for single-track gray encoders to my Inkscape optical rotary encoder disk generator extension. In a nutshell single-track gray encoders are similar to binary-reflected gray encoders because they give absolute position with multiple sensors, and two adjacent positions can […]
I ordered a set of three Yongnuo RF-603 wireless remote flash triggers from eBay for $50. They also work as a remote trigger for the camera as well (each of the modules have a trigger button). They are just plain […]
I recently acquired a pair of HP 6632A power supplies for a very decent price (about 100€ for the pair). These are late 90s models from HP, capable of 0-20V and 0-5A. They have a GPIB port (well actually HP-IB […]