Community Favorite Smoke Detector with Power Shutoff for Printer

For those that don't mind using a soldering iron, I personally am going to desolder the punch-down and just solder the wires in place.
But, in the interest of keeping the DD simple...

 

Controller box here. Did not *quite* get it finished today, we will wrap it up in the morning (have three more wires to land and the box top to finish printing).

These two boxes will connect with a CAT5 cable of any length.
You have an option here of fail-safe or fail-on when wiring this.

depending on how you wire the relays fail-safe means if the cable looses connection the power strip shuts down. Fail-on means the opposite.

I'll be including some basic wire diagrams as well.

The 9v powers the smoke detector (in the other box) and provides power to the relay on the detector that will trip this relay when the alarm goes off. This one is currently wire FAIL-SAFE so lose cable -> lose power. Needed to use an aux relay to be able to supply enough current for a circuit. The relay on the smoke detector is not rated for enough current, this one is >10a AC.

 

@Harry given that this is <$20 in parts RETAIL they really should consider bundling something like this in the printer (or as an add-on)



Safety first after all.

(the SD version will be a lot more cost, but ... Computers!)

 

Minor re-design of the sensor case was needed. Once we started testing it became apparent that how we thought it needed smoke to flow across it was flawed.

It takes it about 10 seconds to activate once the smoke is generated.

Some details on this detector I found here:

http://henrysbench.capnfatz.com/henrys-bench/dyp-me0010-smoke-detector/

He says he saw false alarms. Neither of the two units we have did that.

Soon as we have the new top case printed and tested I will post everything.

Attached are Eagle schematics for the LOGICAL electrical layout. This is NOT the actual electronic schematic since there is a opt-relay module in there (with electronics of its own) and the Smoke sensor is diagrammed as a simple relay as well (and it clearly has some smarts on it).

This is more of an aid to wiring rather than meant to be a real schematic.

STL and 3D models to follow

 

Huzza!

For those awaiting the DD (the dumb detector) I have published it on thingiverse:

http://www.thingiverse.com/thing:1103474

A final pic here of the sensor which needed redo. It now has a lot more airflow.
The smart detector is next. I am working on it now

 

The entire 'DD' rig for reference.

The 'SD' version will be a little larger (to accommodate the extra electronics) but wireless.

 

Every few months I see people (not on the forum here, but .. 'people') trying to rig a smoke detector and I get the joy of pointing them to thingiverse

Which then results in a small flow of people adding this to their collections...

I guess I need to motivate and do the improved wifi one ... Been long enough

 

This was posted recently:

http://hackaday.com/2016/12/07/dont-leave-3d-printers-unattended-they-can-catch-fire/

Duh. That is why this project exists

I am delinquent on getting the "intelligent/wireless" version of the smoke detector up / online so I will prioritize that.