Thanks everyone for your input. Ordered one today. It will go in a small bay near the tail cone of the V2. Yes, Veruca got it! Heavy duty little thing....
RK-----Original Message----- From: William Ferry
Sent: Saturday, February 28, 2015 5:17 PM To: tccrockets@xxxxxxxxxxxxxSubject: [tccrockets] Re: Anyone using magnetic switches for arming altimeters?
Hi Richard,I've used Featherweight Magnetic Switches on almost every flight I've flown with an altimeter so far, I'm happy with it. Mike @ BAR sells them, as do others online. Obviously you have to design your sled so that they're reasonably close to the airframe, and they can be a bit touchy. Sometimes I find when sweeping the magnet past that they toggle twice, so the end state is the same as you started. There's a bright blue LED that lights on the board when it's on, so I positioned the vent holes on my latest rocket's avionics bay such that I can see the LED and get the visual confirmation that it's on or off (of course the beeping of the altimeter can help also).
The board is smaller than a postage stamp, single-sided with surface-mount components. It doesn't have any connectors on it, instead it has 3 mounting holes which double as the electrical connections (GND, IN and OUT, labeled on the back-side). I've heard that there are different versions that are different sizes, so there isn't a single hole pattern that works for every one, but the 4 I have (1 from BAR purchased in 2014, and 3 from Performance Hobbies last month) all happen to be the same. Mine are 3/4" by a bit over 1/2". They go for around $25, and each one has come with the magnet as well. The boards do use a hall-effect sensor to detect the magnet, so even when they're "off" they do still consume a bit of power for the sensor, I never bothered to measure how much as I don't use these switches for long-term powering-down of my altimeters, just to keep them off between when I prep the rocket and when it's upright at the pad, and to turn things off post-recovery to make the beeping stop. =)
I hope that helps. - Will
On Feb 28, 2015, at 9:20 AM, Richard King <drrbk@xxxxxxxxxxx> wrote:Ideally, I would like to arm and disarm using an external magnet. Using simple burglar alarm type switches seems dicey. Does anyone use a switch that is “click-on, click-off” and is small enough for smaller sized AV bays?Thanks! Richard King This email has been checked for viruses by Avast antivirus software. www.avast.com
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