Simple and small temperature fan controll

I published this schematic long ago in this article: Adjustable power supply and since then I made some improvements in PCB to make the board as small as possible. The idea is to be easy to attach the whole board to the heat sink which we want to monitor. The board is only 27mm x 27mm.

Original PICKIT-2

These days I was thinking about a better PIC programmer that can work with Microchip MPLAB IDE software so that I can write my own programs or edit someone else's  programs.
I found that there are numerous versions of the famous Microchip PICkit 2 on the web. Some of them are using the original schematic published by Microchip and some are lite versions - with different parts or simplified schematics. None of them satisfied my requirements. So I got the original schematic, removed the memory chips and the input ICSP connector (which I didn't plan to use anyway) and made a new single sided PCB. I used mostly SMD parts.

Simple LC meter

Here is another piece of laboratory equipment - LC meter. This type of meter, especially L meter is hard to find in cheap commercial multimeters. Schematic of this one came from this web page: https://sites.google.com/site/vk3bhr/home/index2-html. It uses PIC microcontroller 16F628A, and because I recently acquired a PIC programmer, I decided to test it with this project.

Усилвател за слушалки "Ламборгини" (Headphone Amplifier "Lamborgini")

Всъщност схемата на този усилвател е взета от чудесния сайт на Род Елиът и е неговият проект 113.

Платката я проектирах в Eagle. Усилвателят тръгна от първото пускане, като качеството на звука е удивително добро. Мощността е му е достатъчна да захрани дори малки компютърни колонки. Ползвах операционния усилвател NE5532 и крайни транзистори BD139 и BD140.

Преди няколко месеца се наложи да взема кутията на усилвателя и като заместител реших да използвам ламаринената опаковъчна кутия от една тоалетна вода "Тонино Ламборгини". Захранването го направих наново с интегралните стабилизатори LM317/LM337 по схемата от дейташийта. Получи се симпатично малко усилвателче с качество по-добро, отколкото на повечето скъпи фабрични усилватели :)

Update: 11 July 2013

One of my readers ask me to publish the project files so here they are: ESP113
Use them on your own responsibility.
The PCB is different from first version. Now the stereo jack and the RCA connector are PCB mount type.
In the archive I put pictures of the stereo jack connector and the RCA connector for your reference.