10 hours delay analog ckt..

[BABESH]

Hi
any idea on a analog circuit which will oscillate with inerval of 10 hours..
or which can provide delay for 10 hours..

All my circuit is in analog, but to have this requirement i am not willing to use uC,

thanks in advance....
--babesh.

 

[pranam77]

Just have a look at links with Long interval timer with decrete components. Cheers
https://www.electro-tech-online.com...ong-interval-timer-employs-555-chip-timer.jpg
https://kitsrus.com/pdf/k152.pdf

 

[BABESH]

Thanks Pranamm for the reply
Seems this wil work as it is mentioned in datasheet.

I wil have this as an final option if I don't get ckt
which is by opamp based and few external cap and resis..


--Babesh

 

[FvM]

If you really mean analog, without utilizing frequency dividers as suggested, you need Gohm and tenth of uF. It's feasible but not really resonable, I think. Even with low offset FET OPs as capacitance multiplier, you can't avoid high Mohm resistors and high quality foil capacitors. Obviously, the circuit would be highly susceptible to leakage currents and should be coated or molded at best.

 

[BABESH]

Hi FvM,
thanks for your reply and intrest on my topic.

I had that doubt about the cap,res and their reliability, your suggestions supported the same...

now i can drop that idea of using pure analog components and I will think about the using feq divider and ne555 options...

on the whole my task was to acheive 10 hour delay without using a controller and firmware..

Thanks once again
Babesh...

 

[Audioguru]

There are many long duration timer circuits that use a Cmos oscillator and digital divider IC like a CD4060 or a CD4541.

Don't use a lousy old 555 timer.