Re-purposing ideas for smoke detectors circuitry ?

[Externet]

Hi.
They are supposed to have very high gain amplifiers; can heart beating, respiration be monitored somehow using a canibalized one ?
What about a hyper sensitive microphone for listening to termites chewing, checking purity of water for particles/microorganisms in suspension, geolistening, ...
What do you know about them and applicable uses ?
Someone wanted to make a geiger counter... would it work ?

 

[Nigel Goodwin]

Just opamps, use an opamp or two - nothing special about them. Historically there were a number of projects in magazines for making your own, as far as I'm aware you can still buy the individual sensors.

There's a simple one here:

Smoke Detector Alarm Circuit

Practically Tested Smoke Detector And Alarming circuit with very low cost and high accuracy is explained here.

www.electronicshub.org

 

[ronsimpson]

Re-purposing ideas for smoke detectors

I have never copied a .GIF before. Maybe it will work.
----edited-----
Thought it might work but no. Target practice.

 

[Nigel Goodwin]

View attachment 132695
I have never copied a .GIF before. Maybe it will work.
----edited-----
Thought it might work but no. Target practice.

If I could click like more than once I would!

 

[unclejed613]

as far as I'm aware you can still buy the individual sensors.

as long as you don't buy too many of them... https://en.wikipedia.org/wiki/David_Hahn apparently he used the americium from a lot of smoke detectors to make a neutron source, with the goal of making a working "backyard" breeder reactor... just a neutron source alone can be a safety hazard.