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??)
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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.
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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.
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Corrected & modded circuit uploaded.