Morris
Are you switching off the HT/EHT to the tube when the heater is off as
well? My understanding is that it is not good to switch the heater on
while there is full HT on any thermal valve/tube.
You might take the opportunity to "soft start" the CRT heater - I can PM
you a schematic I'm using if you wish?
Cheers Grahame
On 10/08/2014 10:00, Morris Odell wrote:
Hi all,
Latest progress on the Sperry radar clock - I found a very helpful
transformer manufacturing shop whose owner was happy to vacuum
impregnate and bake the howling transformer for me. Alas, it only made
a very small difference, if any. It sounds like the problem is
magnetostriction in the core so there's no easy solution. I've rubber
mounted it to try to stop the rear chassis panel from acting as a
sounding board but that's all I can do I think. Hopefully it will be
quieter when it's all buttoned up.
Right now I'm working on a PCB which will contain a PIR motion
detector and also a Xbee wireless receiver to pick up the GPS data
that I have sent around my house.
I also have a question - among other things the PIR motion detector
switches the power to the CRT heater. Is it worth dribbling a little
bit of current through the heater when it's off so that it heats up
faster when the PIR senses an observer? If so, how much? The CRT
heater draws 300 mA at 6.3 volts when it's working but takes about a
minute to get to full emission. Will preheating it like that shorten
its life significantly?
Any opinions much appreciated,
Thanks, Morris
On Monday, July 14, 2014 7:02:47 PM UTC+10, Morris Odell wrote:
Hi all,
I've got the clock displaying time now. The video shows it upside
down on the bench so it's at a few minutes past 12. That howling
power transformer is a distraction, I'll have to wrap it in some
sound absorbing material especially as I like to add Westminster
chimes to my clocks :-).
The next step is to put it all together and tidy it up!
https://www.youtube.com/watch?v=tL3840bE9Cs
Morris
--
You received this message because you are subscribed to the Google
Groups "neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send
an email to neonixie-l+unsubscr...@googlegroups.com
<mailto:neonixie-l+unsubscr...@googlegroups.com>.
To post to this group, send email to neonixie-l@googlegroups.com
<mailto:neonixie-l@googlegroups.com>.
To view this discussion on the web, visit
https://groups.google.com/d/msgid/neonixie-l/99d0f7d2-28a1-41d6-8d57-c959754607fb%40googlegroups.com
<https://groups.google.com/d/msgid/neonixie-l/99d0f7d2-28a1-41d6-8d57-c959754607fb%40googlegroups.com?utm_medium=email&utm_source=footer>.
For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups
"neonixie-l" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to neonixie-l+unsubscr...@googlegroups.com.
To post to this group, send an email to neonixie-l@googlegroups.com.
To view this discussion on the web, visit
https://groups.google.com/d/msgid/neonixie-l/53E73641.9090806%40googlemail.com.
For more options, visit https://groups.google.com/d/optout.
