Circuit Schematic and Board Design

The Speleonics Michiephones circuit and board design can be downloaded from here. Please read the licence conditions.

License for the Schematic and Board

The schematic circuit for the original Michiephone as developed by Neville Michie is in the public domain [see Reference 1]. Speleonics has build upon that design and incorporated other circuit ideas which are also in the public domain [see Reference 3]. To put something back into the community my modifications, the Speleonics Michiephone Schematic Diagram and the Printed Circuit Board Design, are available here. Note however that the Schematic Diagram and the Printed Circuit Board Design are available under different conditions as follows:

The Speleonics Michiephone Schematic Diagram is hereby placed into the public domain.

The Speleonics Printed Circuit Board Design is hereby released under the following license conditions:

The License:
- You may use Speleonics Michiephone Printed Circuit Board Design verbatim to produce Michiephones for your own private use, for the use of your caving club or for a cave rescue group.
- You may publish this circuit board design in your club journal, on your web site or your club's web site for the purpose of allowing others to make Michiephones based on this circuit board design however this License must also accompany that publication.
- You can't take the Speleonics Michiephone Printed Circuit Board Design and sell Michiephones based on this circuit board design unless you contact me and arrange a license to use the board design.
If you want to sell Michiephones based on the Speleonics design you may start from the Speleonics Michiephone Schematic Diagram (which is in the public domain) and design your own printed circuit board. This is not an unreasonable request given that you can use the Schematic diagram freely as it is in the public domain.
Finally there is NO WARRANTY on any of these schematics or board designs.

The modifications to the basic design that Speleonics has made is detailed in the Technical Information section.

Download the Schematic Diagram and Printed Circuit Board Design

The schematic and circuit board were scanned from printed versions as the schematic is still in an old DOS based PCB design program. Later when I port it over to a Linux based CAD system I will put up an electronic version and a Gerber plot of the board. The Gimp image format of the board may be useful for you if you want to clean up the original image and make circuit boards from printouts of that.

Also grab the Bill of Materials for the parts list: mph_bom.pdf (45 kB)

Image JPEG format Gimp format
Michiephone Handset Circuit Board Schematic
(version 2.0)		 mph_schem2.jpg
(900 kB)		 mph_schem2.xcf
(640 kB)
Michiephone Handset Printed Circuit Board Design
(version 2.0)		 mph_board2.jpg
(600 kB)		 mph_board2.xcf
(190 kB)