Zak Kemble

Author's posts

CPU Usage LEDs

This project has now become the AVR USB RGB LED Controller project. The CPU Usage LEDs host program can be found in the examples directory. Having seen a few circuits around the web that light up LEDs depending on CPU load I decided to make my own since they do look pretty cool 😀 I …

Continue reading

AVR microcontroller based PWM fan controllers

If you’d like a fan controller kit please email me at blog@zakkemble.co.uk Kit: £10 Post: £2 if you’re in the UK, otherwise £4 Microcontroller will come programmed and ready to go. Only available while stocks last! So this is a bit of a continuation on my 555 timer based PWM controllers, but now using microcontrollers …

Continue reading

First time with Arduino and AVR microcontrollers

Audio VU meter

I had been eying up Arduinos and looking into getting started with digital electronics for a while and now finally brought an Uno along with a 16×2 character LCD with RGB backlight. Wow. It’s like I’ve unlocked a whole new world of electronics, for years I’ve looked at digitally controlled devices like LCDs woundering how …

Continue reading

IR jammer

IR Jammer

This is a simple 555 timer based circuit which can jam IR (Infrared) communications like TV remotes, when I first made the circuit (October 2011) it was a bit iffy at jamming IR and eventually stopped working for some reason, it wasn’t until recently that I brought a mini DSO and found out it needed …

Continue reading

LEDs looking pretty

I haven’t really used LEDs all that much other than as power indicators or in a joule thief, perhaps it time to make some pretty flashy things. 😀 I went searching for some LED flashing circuits that would be able to have at least 4 LEDs with minimal components and came across 2 that I …

Continue reading

PWM Fan controllers using the 555 timer IC

Here I made 3 slightly different PWM fan controllers based on the 555 timer for controlling a large server fan – Delta FFB1212EHE, 3A peak, 2A normal load, other features of these controllers are to boost the fan on to 100% for the first few seconds of receiving power and a ‘turbo’ button to set …

Continue reading

Joule Thief

In case you’ve not heard of a joule thief before, they’re simple voltage boost circuits, usually used to drive light loads like LEDs with a single battery cell, even batteries that other electronic devices consider ‘dead’ can be used, [Wikipedia article]. I made 2 versions of the joule thief, the common one with a single …

Continue reading

FM Radio Transmitter

Here’s a nice little FM radio transmitter, it has a range of about 100m – 200m with a 12V supply, decent audio quality and the microphone is very sensitive, with a 5pF – 30pF variable capacitor the transmitter can tuned between 87.5MHz – ~98MHz, however at the higher frequencies it’s much less stable and more …

Continue reading

Load more