Heathkit ID-1590 weather station adapter

[james_s]

Some time back I found a neat old Heathkit ID-1590 wind speed/direction console. This is a neat little unit that has a Panaplex neon display for the wind speed and arrows backlit with small incandescent lamps to indicate the direction. The original Heathkit sensor booms are the same as used on the much more valuable weather computers they offered and are as rare as hen's teeth. Being outside on the roof they deteriorated over time or got left behind when people moved or passed away. Modern wind vane sensors are mostly potentiometer based while Heath used 8 reed switches activated by a magnet on the rotating vane assembly. To multiplex 8 switches over 5 wires they divide them into two banks, one for each half cycle of the AC power out of the transformer.

I developed an adapter that allows a modern wind vane such as that used by the Davis VantagePro weather station with the old Heathkit console. When the original incandescent lamps are still used the adapter can utilize "phantom power" without requiring a separate power source or any modifications to the console. I designed it on the fly mostly around parts I had on hand so there may be a better way of doing things but this has been working very well. Since I only needed one and assume the market is very small I just built it on a protoboard and didn't bother to lay out a PCB. I'm releasing all of the source into the public domain in hopes that it will be useful to somebody else who has a ID-1590 or similar console.

https://github.com/james10952001/Heathkit-ID-1590-adapter