Re: [CAD_CAM_EDM_DRO] Tach Sensor

<snip>

Every PC Computer fan (from power supplies, etc) I've ever taken apart has
had 3 hall sensors in them. And a magnet on the rotor, too. As the magnet
hits the sensor, it triggers the 'next' coil to be energized, advancing the
magnet to the 'next' sensor.

- Steven Ciciora

>> Hi Bill,
>>
>> I don't think I'd try to wind a pickup coil. A Hall-effect device is
>> what's called for. Got any scrap 5" floppy drives? They often had
>> them. I recall an old thread that posted a PN# for a useable device.
>>
>> Probably much easier would be to use a reflective optical pickup. Check
>> out what Dan does at Camtronics. The sensors are available at DigiKey
>> too.
>>
>> Alan KM6VV
>>