Electronic – Where to decouple battery in circuit with power switch

I'm starting to feel like an old engineer suggesting these so frequently recently, but you can use a 555 timer in monostable operation. When triggered (by the alarm), these maintain high signal for a set amount of time and do not accept additional triggers during that time.

You might need to make this as two stages if the original alarm signal continues to set one off when triggered (like if the alarm signal is the driving signal for a buzzer). The way that works is one is high for the length of the buzzer, accepting no other triggers, the output of the first stage triggers the second, which is monostable for the length of the vibration motor. Basically this allows both to be triggered on the same edge, but the shorter duration one can not be re-triggered until the longer duration has run out.

1. Some deep-space vehicles use radio-active thermal radiation + thermo-couples to produce electricity. Obviously, you can't use a radio-active source, but you might want to research how much energy could be generated using body heat + ambient heat for your system. If there is sufficient energy, then you may be able to power your tiny system

2. Another possibility is harvesting kinetic energy generated by walking--however, that would require more hardware than simply using a high-energy cell in your system--so unless weight & cost aren't majors factors, then that idea probably won't be useful. Nevertheless, check this out. Here is another reference that may be useful to you.

Note: I imagine your best choice would probably be a rechargeable li-ion cell though, with respect to overall cost & weight factors.