I Want To Make A Device That Tells Me That Electricity Is Back

[AnalogKid]

CD40106 driving a piezo beeper?

 

[FuZZ1L0G1C]

@tonitobato - do you have electronics construction skills?
(component identification, soldering, safety knowledge (mains V!!) )
Otherwise get somebody to build it for you.
If so, read schematic below.
Mine used buzzers (active piezo sounders), but you can replace with dropper resistor/LED.
Hope it helps.

 

[bushtech]

Thanks for this FuZZ1LOGIC. I need these as well thanks to SA's prince of darkness.

 

[bushtech]

In South Africa and probably a lot of Africa the power can go on off up to 5 times a minute or stay off for a week. I'd rather automate the notification

 

[kellys_eye]

In South Africa and probably a lot of Africa the power can go on off up to 5 times a minute or stay off for a week. I'd rather automate the notification

From what I hear in the media you may as well make arrangements for zero power permanently!

 

[bushtech]

Done already. But installed a lp gas generator for when the petrol (the other gas for the US citizens here) runs out. Which is a distinct possibility since since some clever chappie sold South Africa's fuel reserves

 

[AnalogKid]

@tonitobatoIf so, read schematic below.

In the blackout alarm schematic, to me it looks like the beeper is on continuously when power is good. With VR1 at its minimum value, there still will be Vcc/2 across the Q1 base-emitter junction plus D1. So for any Vcc above about 3 V, Q1 will be on. Also, D2 in series with C2 doesn't make sense to me. Or am I missing something?

In the mains restored alarm, the 555 pinout is incorrect.

ak

 

[FuZZ1L0G1C]

In the mains restored alarm, the 555 pinout is incorrect.

Correction to 'Mains Power-On' circuit:
Thanks for the heads-up re circuit-errors @AnalogKid .
Mains power-on was an old hand-drawn circuit in a notebook.
I omitted joining "dot" (D1/D2/BZ1) & didn't verify it before 1st post. (need new specs??)
---
Mods:
Found circuit was occasionally self-triggering so added C5 & C6 bypass / decoupling caps.
Full '555' IC Data obtained from Wiki.
Circuits orig. from public-library reference-section 'archive' material c. 1980's.
---
Removing / swapping bad for new images:
If possible, can mods please replace first circuit with this correct one ?
Corrected Mains-failure alarm will follow.
Thanks again.
---
Corrected & modded circuit uploaded.

 

[Bluejets]

That works only if the radio is plugged into an outlet that is *not* powered by the backup generator.

ak

I thought that would be obvious...

 

[dorke]

Well,
You could use an old VCR plugged directly to the electric company feed.
They start blinking (no sound) when the power is back on.

 

[(*steve*)]

One simple circuit would be to have a latching relay which removes power from a flashing light.

So, when power is initially applied, the light starts flashing (powered via the n.c. contacts of a relay). Pressing a button pulls in a relay which uses the n.o. contacts to keep it powered.

Once the button is pressed, the flashing light will stop flashing until power is removed and reapplied.

 

[FuZZ1L0G1C]

Take 1 x high-speed floor-standing fan.
Using stiff cardboard, attach a strip to the finger-guard at back so that blades hit cardboard.
Bend remaining card sheet into a large cone fixed to the front.
Force a referee's whistle into the tapered end.
Place fan next to bed, select highest speed, plug in to mains outlet socket.

 

[dorke]

Take 1 x high-speed floor-standing fan.
Using stiff cardboard, attach a strip to the finger-guard at back so that blades hit cardboard.
Bend remaining card sheet into a large cone fixed to the front.
Force a referee's whistle into the tapered end.
Place fan next to bed, select highest speed, plug in to mains outlet socket.