Mains light-on indicator

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M.Joshi

Member
Hi,

Could anyone tell me how I can design a mains light-on indicator to fit into the back of a standard light switch plate. I would like an L.E.D to flash every second and a beeping sound every 5 minutes while the mains light is on.

Thanks.
 
Timer

Can anyone recommend a suitable I.C other than the 555 to generate the beeping sound every 5 minutes?
 
You can use anything you like to generate delay and tone signal.
It doesn't have to be 555. Actually I don't really like 555 because
of pin arrangement. You can use TTL or CMOS chips...
Maybe you prefer bipolar transistors? Maybe UJT or PUT?
Or microcontroller?
 
Bipolar Transistors / UJT

Hi,

Is it possibly to accurately generate a long delay with Bipolar transistors / UJT's?

Could you tell me where I could find information on how to generate long time delays using TTL / CMOS I.C's.
 
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