[Rack] Electric door strike working again. Use your Pin or key to get in.
jof at thejof.com
Mon Jul 15 07:22:08 UTC 2013
Yeah, so what's the new motor? I haven't been by in a few days.
Is this just another buzzer, or some kind of rotationally-driven mechanical
Either way, sounds like some cool progress is being made.
On Sunday, July 14, 2013, Henner Zeller wrote:
> > Quick thing--
> > Remember that Fire Code requires that any electric door strike, or
> > magnetic strike, must allow someone to leave without being impeded in
> > a panic. On magnetic doors, this requires a panic push bar that
> > physically breaks the electrical connection. On mechanical electric
> > strikes, this requires that either a pushbar or simple lever be
> > pushed/rotated to bypass the electrical lock.
> The regular lock will just work the way it is now - by rotating the lever.
> > -M
> >>> The motor Scotty found takes about 300mA at 6V when free-running (so
> >>> for no-load 'return', maybe 500mA with load). It runs about 1 second
> >>> for the amount of time we need. That is about 1.8 Joules.
> >>> Say we can charge up a capacitor to 18 V (peak voltage of a bit more
> >>> than 12 V AC) and drain it down to 4 V (when this particular motor
> >>> just works), then we'd need about 20'000 microfarad ( 2 * 1.8 joules /
> >>> ((18 - 4) volt)^2 ). The calculation would be similar for other
> >>> motors found in the pile.
> >> there are at least ten 1000 microfarad capacitors rated at 50 volts in
> >> pile, and i can certainly find more. But i think the math is more
> >> complicated. But since it's based on voltage squared, one 50 volt 1000
> >> capacitor is the same energy as a 20,000 uF capacitor rated at 11.1
> >> anyway that motor sounds hella weak. The motor i already mounted on the
> >> door is rated 24 volts and probably can take a good amp or two at least,
> >> which is a lot more power.
> >> _______________________________________________
> >> Noisebridge-discuss mailing list
> >> https://www.noisebridge.net/mailman/listinfo/noisebridge-discuss
> Noisebridge-discuss mailing list
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Rack