Cruisers Forum
 


Join CruisersForum Today

Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 18-06-2018, 11:24   #16
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 15,147
Re: EPIRB BATTERIES

"The manufacturers aren't keen to tell you if they have taken a shortcut "
What, even in Oz? (G)

I know that certain big-name electronics makers have actually employed what they sometimes call forensic engineers, who will literally take a newly designed circuit board and literally comb over it saying "We don't need that part" in order to make it cheaper to produce--and often, inferior to what was designed and actually certified for the market. Those unpopulated items on the circuit board usually were their victims.

The idea of letting the GPS module sleep every so often doesn't seem really crazy to me though. For someone in the water or about to be, perhaps moving at 2-6 knots? Even if that is a 30-minute sleep and the position is then 3 miles off, that still should be enough to get rescue assets launched, and well within the homing range of the 121.5 signal. Given how quickly a gen-3 GPS chip can wake from sleep and reacquire position, having them sleep for 5 or 10 minutes should really be a trivial matter. From the designers' perspective...games like that would allow for smaller batteries and smaller units, and that's got to be a competitive pursuit.
__________________

hellosailor is offline   Reply With Quote
Old 19-06-2018, 01:47   #17
Certifiable Refitter/Senior Wannbe
 
Wotname's Avatar

Cruisers Forum Supporter

Join Date: Jan 2008
Location: South of 43 S, Australia
Boat: C.L.O.D.
Posts: 8,903
Re: EPIRB BATTERIES

Quote:
Originally Posted by hellosailor View Post
.........
The idea of letting the GPS module sleep every so often doesn't seem really crazy to me though. For someone in the water or about to be, perhaps moving at 2-6 knots? Even if that is a 30-minute sleep and the position is then 3 miles off, that still should be enough to get rescue assets launched, and well within the homing range of the 121.5 signal. Given how quickly a gen-3 GPS chip can wake from sleep and reacquire position, having them sleep for 5 or 10 minutes should really be a trivial matter. From the designers' perspective...games like that would allow for smaller batteries and smaller units, and that's got to be a competitive pursuit.
My bad, I didn't explain the issue very well in my previous post. You are correct, having the GPS asleep for 5 or 10 minutes is not a problem and the better beacons do it this way. IMO, 30 minute sleeps are getting borderline.

The real problem is when the GPS engine is only used once and the coordinates are transmitted only once or just gets repeated over and over again (i.e. not updated). The next worse is when the GPS is only active for say a couple of times in the first hour or two and then is turned off completely. As far as certification goes, such units can be described and sold as GPS embedded EPIRBs.

I think these dodgy techniques are not as prevalent in newly designed beacons as they once were.
__________________

__________________
All men dream: but not equally. Those who dream by night in the dusty recesses of their minds wake in the day to find it was vanity: but the dreamers of the day are dangereous men, for they may act their dreams with open eyes, to make it possible. T.E. Lawrence
Wotname is offline   Reply With Quote
Old 19-06-2018, 10:45   #18
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 15,147
Re: EPIRB BATTERIES

Dodgy would be a way more polite term than I'd use for that!

Thanks for the info.
__________________

hellosailor is offline   Reply With Quote
Reply

Tags
epirb

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
EPIRB's are NOT dead! / EPIRB Activation? What happens/How to improve rescue odds!! ka4wja Marine Electronics 95 30-07-2018 11:03
Epirb Batteries Emmalina Marine Electronics 8 22-07-2017 21:46
Replacing batteries on '88 vintage ACR RLB-14 EPIRB Tailwheel Marine Electronics 5 12-12-2015 15:02
EPIRB recall (GME EPIRB's manuf from 2005-2008 Recaledl) ka4wja Marine Electronics 3 23-07-2014 14:52
Golf Cart Batteries vs Marine Batteries Bill Estes Electrical: Batteries, Generators & Solar 52 26-01-2010 23:28



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 11:58.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.