[time-nuts] Question for my new GPSDO Heater

[Mark Goldberg]

I created a temperature test setup for my TCXOs. Relay control did not last
long because the relay was operating once a second or so and the Peltier
uses a lot of current. The relay contacts welded in a few hours. Luckily I
was watching when it happened. A PID controller running H bridges works a
lot better to control the temperature accurately. I made a custom control
algorithm that ramps the temperature up and down and takes frequency
readings. There are temperature control algorithms that are supposed to
automatically tune the system gains, but I have not tried them.

https://sites.google.com/site/markstcxo/home/test-jig

73,

Mark
W7MLG


On Sat, Oct 12, 2019 at 7:00 PM Perry Sandeen via time-nuts <
time-nuts at lists.febo.com> wrote:

> Yo Bubba Dudes!,
> The suggestion was made to use a ebay item number 192112054053 heater for
> this project.
> Now it's cheap and has a digital reading.
> BUT
> It is a bang- bang controller using a relay.  At some point that relay
> will stop working.  Also all designs I've seen for good temperature control
> use proportional solid state controllers.  There are plenty of free designs
> on the internet.
> Lastly, if one believes that this is long term reliable controller that
> will deliver .1 degree accuracy, for that price, please contact me off line
> and I will set you up with some really cheap (but slightly scorched and a
> burned wood smell) lots to where you can build your dream home here in
> California.
> Regards,
> Perrier
>
>
>
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