Re: RE- panic button

Subject:     Re: RE- panic button
      Date:  Tue, 10 Jun 1997 19:15:15 +1000
      From:  Peter Electric <elekessy-at-macquarie.matra-dot-com.au>
        To:  Tesla List <tesla-at-pupman-dot-com>
References:  1

Tesla List wrote:
> Subject:      RE- panic button
>        Date:  Mon, 09 Jun 1997 12:57:00 GMT
>        From:  robert.michaels-at-online.sme-dot-org (Robert Michaels)
> Organization: Society of Manufacturing Engineers
>          To:  tesla-at-pupman-dot-com
> T>  From: "William Noble" <William_B_Noble-at-msn-dot-com>
> T>there is a switch made for use on jacuzzis where shock hazard is
> pretty
> T>significant.  The switch is pneumatic - there is a button that you
> T>install
> T>near the jacuzzi, and then a 1/4 inch plastic hose (like aquarium air
> T>line)
> T>that runs to the pump controls.  pressing the button starts/stops the
> T>blowers
>  [ ... ]
>         There's one thing about your idea which I completely dis-
>         like:
>                    I wasn't the one who thought of it!
>         My only concerns in implementing it are whether the pneumatic
>         button must pushed  =hard=  to send a proper air pulse
>         to the controller;  also how much  of a delay there might be
>         between the button-push and the controller's reaction.
>                 With an electrical E-Stop push button, only a
>                 delicate touch is necessary to break the normally-
>                 closed contacts.   The signal, of course, is sent
>                 with electric speed.
>                                         Pushing on, in --
>                                         Detroit, USA
>                                         Robert Michaels

I have these controls on my spa (Jacuzzi) and they do get a bit dicky
after a while, i.e. you have to press it a couple of times to get it to
work. The other problem I see is that if you have a fairly long length
of tubing, pressing the button wouldn't build up enough pressure to
trigger the switch.

Maybe if one attached a squeeze bulb instead of a button, such as on
boat fuel primers, the thing might work better.


Peter E.