[time-nuts] Designing and building an OCXO and GPSDO

[Björn Gabrielsson]

Hi Philip,

On Sun, 2008-08-10 at 22:45 +0100, Philip Pemberton wrote:

>    As far as temperature regulation goes, I'm going to use a PIC 
> microcontroller (one of the 8-pin chips with an A/D converter) to monitor the 
> temperature of the crystal, and use a PID loop to control the two power 
> transistors to maintain a temperature of 50C +/- 2 Celsius (the accuracy spec 
> of the temperature sensor). I also have other higher-accuracy sensors (Dallas 
> DS18S20 and DS18B20) that I can calibrate with; these are accurate to around 
> half a degree Celsius with a resolution of 0.5C.

Here is an example of a kind of synthetic TCXO using Dallas temp sensors.

   http://www.ijs.si/time/temp-compensation/

The resolution of the DS18x20-sensors are better than 0.5C.


--

    Björn