DIY Oxygen Analyser PCB

Updated 12-4-2003

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Parts list

The board:

board size

The final dimensions of the board are shown here, be careful not to cut it too small or it won't be retained by the grooves in the box.

The taper on the sides of the board are so it slides into and is supported by the channels within the case. The chamfers at the top allow the lid to fit properly.

For those without access to a LASERjet printer who may want to use an etch resist pen to create the board, an image of the copper side of the p.c.b. is shown below. The component holes are based on a 0.1" (2.54mm) pitch.

O2 analyser board

Component layout:
Be careful to observe the polarity of the diodes, the capacitors if electrolytics are used and the orientation of the transistors and U1. Be aware that the diagram below is based on Q1 & Q2 being 2N7000 transistors: Alternative devices may have different pin-outs (i.e. if you use say BS170's, they'll have to be rotated 180 degrees as the drain and source are reversed on this device).

O2 analyser layout

Below are shown views of the pinouts of the two varieties of diode as well as the pinouts of 2N7000 and BS170 transistors (viwed from the bottom).

device pinout

And finally, the finished board.

Finished board

Parts list
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Contact: Dave Cordes.