How EXACTLY do immesion heater tank thermostats work ?

[Avo Mk8]

Hi Brian.. The second option is the solution used in high class work.. It involves drilling the bob with a shelf half way up.. and using an Invar tube back down to the rating nut.. Beyond my workshop capabilities.. But a small weight on a brass weight below is possible..food for thought there ! Thanks..

And then the next improvement is to deal with changes in barometric pressure! Happy New Year

 

[RogerJ]

And then the next improvement is to deal with changes in barometric pressure! Happy New Year

Yep..the final frontier ! I have a net friend in Canada building a similar clock but with micrprocessor (Arduino) control of the pendulum swing with plans to deal with baro. pressure. Sadly I can't program such things ! My clock is here: A DIY, NON Hipp Toggle master clock. - http://www.rogerj.co.uk/clock2.htm
@ AVO Mk8. . My first job intoduced me to the AVO 8 (and the Tektronics 535A) but I couldn't afford one in the '60's. Twenty years ago they were cheap as chips and I now have 12.. one of every Mk I think.. but mostly use a ten quid digital now..

 

[Avo Mk8]

@ AVO Mk8. . My first job intoduced me to the AVO 8 (and the Tektronics 535A) but I couldn't afford one in the '60's. Twenty years ago they were cheap as chips and I now have 12.. one of every Mk I think.. but mostly use a ten quid digital now..

If you've got one of the very first wood cased Avo's I'm really jealous!

My father 'bribed' me to work at my A levels by saying if I got the grades I needed he would buy me an Avo 8 (my choice of reward - what a geek). It's been in use for 55 years until my wife bought me an Avo 410 (isn't a 'real' Avo!) as a birthday present last year. Wow, I can measure capacitance!

Well done with the clock

 

[RogerJ]

If you've got one of the very first wood cased Avo's I'm really jealous!

Nope... Nothing before the black plastic Mk1.. I got as far forward as getting a DA116.. Also not a "real" AVO !

And finally.. @brianmoore.. Quote "Couldn't you get the same effect with a small additional weight attached to a brass rod, under the main bob? That weight moves down to slow the pendulum to counteract the expansion of the main bob speeding it up."

Thinking about it a bit more.. that option would be cumbersome - clock geeks will know that the most sensitive place to move a weight on a pendulum rod it half way up.. Here a small weight would suffice.. BUT in this instance a THIN plain steel rod of the about 18" would move a small weight in sympathy with the bob.. However expansion of that rod would increase the "gain" - the opposite of its use in the stat. But it would have a completely different thermal hysterisis from the bob and may not be such a purist solution..

 

[DPG]

Interesting stuff. Will have a proper look at your web page later.

 

[PEG]

I trust all of you are in good shape,after celebrating the new year

I include the OP.....who raised a glass,4 seconds after the rest of us

 

[RogerJ]

LOL...Thank you PEG and Happy New Year to all on the forum.. In the event last night the clock ws only about 0.1 seconds slow last eve (was reset last Thursday) and I got the the time from Jools Holland anyway..

 

[brianmoooore]

I got the the time from Jools Holland anyway..

Can you anymore, in these days of digital everything?
Back when TV and radio were all analogue, if you listened to Big Ben on any device, the chimes were in perfect sync, and, I assume, accurate.
Nowadays, there's a noticeable difference between devices of the same type, such as TVs in adjoining rooms, radio different again, and if you start adding streamed sources, can be a minute or so behind the others.

 

[RogerJ]

Good point..In the good old analogue days transmission route delay was neglible. Big Ben is maintained by its keepers and no doubt on new years eve is tweaked to be as close as possible to GMT at midnight.. The pips are of course electronically generated by a source fed from a Caesium atomic clock..
I believe the delay via freeview is about 2 seconds.. Cable, Satellite and internet delivery may be a bit longer (and all different) Delay on DAB radio is significant and depends a lot on each radio's decoder (speed ,quality).. On NYE Jools is good enough for me and I reckon I was in sync with all indoor celebrators

 

[brianmoooore]

I regularly watch F1, using feeds from various places for commentary, pictures and data screens. There can be up to 90 seconds difference between identical picture feeds, and anything up to two and a half minutes difference for the other stuff.
Radio Five Live commentator usually says exactly when pit exit light goes green, specifically for the purpose of synchronising their commentary with whatever picture feed you're using.