February 2007 Issue
A summary of this month's contents.
12V Deep Cycle Battery Charger (Part 2)
Full constructional details are supplied in the second part of our project. Our Deep Cycle Battery Charger is a sophisticated unit that is specially designed for deep cycle batteries and will charge at up to 16.6 Amps.
PIC Digital Geiger Counter
Using the power of a PIC 18F2455 at its heart, our new Geiger counter detects ionizing radiation and can capture data for later downloading onto a PC. This portable device has an integral high voltage supply to drive a compact Geiger Mueller tube. Data is displayed on a 4-line LCD display. Built-in USB interface for computer uploading, and the free PC software is written in the latest version of Visual Basic.Net.
PLEASE TAKE NOTE: A REVISED DIAGRAM HAS BEEN ISSUED FOR THE MAIN P.C.B. THE NEW OVERLAY DIAGRAM INCLUDES SOME DETAILS OMITTED FROM THE PUBLISHED ARTICLE. It is sent with all PCB orders, and is available in the PCB Downloads section along with the PCB masters, as usual. (See March 2007 edition for a corrected image.) Unfortunately the Parts Listing for the Capacitors and Resistors is incorrect. Except for VR1 (which should be 100k) the values in the circuit diagram are correct.
Courtesy Light Delay
Give your car that luxury feel with our courtesy light (dome light) delay unit. Uses a MOSFET and opto isolator to safely and effectively fade the light once the door has been closed. Adjustable period from 7 to 40 seconds. No standby current means no battery drain, and it works on any 12V system. Can also be modified for 24V truck systems.
Source codes 0207.zip
PCB artwork pcb0207.zip
PLEASE TAKE NOTE: Geiger counter corrections
As from July 2013 issue PCB artwork is available free to subscribers only.
Non-subscribers may purchase artwork files for a nominal sum. Please contact our Orders Dept for information or to place an order.
EPE Printed Circuit Boards
We can supply ready-made printed circuit boards (8-digit order codes) to the original design specification via mail order or from our Online Shop.