Your GPSr Can Never Run Low on Power Again

[romsk]

My GPSr is designed for the car not for GeoCaching, so when the internal battery runs low there is no way to replace the battery (unless I take the whole thing apart ), so I usually have to call off the hunt and recharge in the car or at home. Being an Electrical Engineer, I was able to adapt my hand cranked AM/FM/SW radio to supply power to my GPSr. With parts from Radio Shack (I didn't want to wait overnight for a Digikey order), I made a simple cable to connect from the radio's power selector switch (by way of a connector I mounted on the radio) to my GPSr. Now, I can power my GPSr from its internal batteries, from the radio disposable batteries, from the radio Nicad rechargeable battery, or by hand cranking! I velcroed my GPSr to the back of the radio (so the radio's built in flashlight faces forward). Now I can crank and walk (even at night) and never have to to worry about loosing power again. If you would like more tips on this, please feel free to respond. Or just tell me your tricks in the field!

Edited September 18, 2007 by romsk

[+KBer]

Can you post a picture? I would like to see this.

[+wesleykey]

Sounds interesting indeed. I use rechargeable batteries in my Garmin 60Cx.

[romsk]

Can you post a picture? I would like to see this.

 

Wow! That was fast. Yes, I will try to post a photo later tonight. I am heading out now to hit a cache.

 

Thanks for the reply

[+Vinny & Sue Team]

My GPSr is designed for the car not for GeoCaching, so when the internal battery runs low there is no way to replace the battery (unless I take the whole thing apart ), so I usually have to call off the hunt and recharge in the car or at home. Being an Electrical Engineer, I was able to adapt my hand cranked AM/FM/SW radio to supply power to my GPSr. With parts from Radio Shack (I didn't want to wait overnight for a Digikey order), I made a simple cable to connect from the radio's power selector switch (by way of a connector I mounted on the radio) to my GPSr. Now, I can power my GPSr from its internal batteries, from the radio disposable batteries, from the radio Nicad rechargeable battery, or by hand cranking! I velcroed my GPSr to the back of the radio (so the radio's built in flashlight faces forward). Now I can crank and walk (even at night) and never have to to worry about loosing power again. If you would like more tips on this, please feel free to respond. Or just tell me your tricks in the field!

Particularly because the OP claims to be an EE (my first career was electrical engineering), I suspect that his post is a not-very-elaborate satirical spoof, much along the lines of the silly and nonsensical "battery tricks" videos currently being discussed on a thread in the Geocaching Topics section. However, the problem here is that if someone takes the OP's assertions literally, they could do some serious harm to their GPSr or whatever piece of equipment that they are trying to power.

 

The reality is as follows: Yes, of course it is possible to power any portable battery-powered electronic device using an external DC power source, but the reality is -- and this is what the OP entirely omitted from his post -- is that one must pay exacting attention to the following two factors if they wish to avoid possibly blowing up their electronic device:

• matching polarities of the source and the device to be powered and perhaps adding a series diode (a cheap 3 to 5 amp-rated 500 PIV power diode with axial leads will do) to prevent damage to the device if someone makes a mistake and accidentally provides reverse polarity.
  
• ensuring that the voltage under load provided by the external source is about the same as the voltage that was provided under load by the original battery in the device, and no more than 1 or 2 volts higher than that.
  
• lastly, there is the issue that most cheap hand-cranked DC generators supply very "dirty" and choppy DC power, with strong AC ripple, as most of them do not contain any significant amount of smoothing capacitance on-board. While some modern electronic devices may function fine when offered such "dirty" DC power, most will not function well, and one would first need to place some hefty ripple/noise-smoothing capacitors (sometimes called "filter capacitors") across the DC source to clean up the DC power before attempting to power the device in question
  

I suspect strongly that if the OP were truly an EE and had intended to send a sincere and serious post, they would not have omitted mentioning the above-listed precautions, and would also have mentioned a bit about the possible need for voltage-regulator circuits (regarding the second item iterated above.) So, my final read here is: a very juvenile and amateurish attempt at a spoof.

 

Oh well.

 

Of course, it is always possible that the OP simply assumed that most or all geocachers are very savvy about electronics and related matters such as the basic principles of physics and electricity -- as would have been true of an audience of ham radio operators twenty or thirty years ago (no longer; ham radio technical knowledge requirements have been very much watered down over the past 20 years) -- but a quick glance at the posts on these forums would demonstrate that such is not the case.

 

All very odd, I must say... And I note that this thread was started only days after that mysterious massive "meteorite" crashed in a remote area of the Andes in Peru...

[+Sioneva]

 

<snip>

 

All very odd, I must say... And I note that this thread was started only days after that mysterious massive "meteorite" crashed in a remote area of the Andes in Peru...

 

What is the correlation here? And where can I get more info on the meteorite, or whatever, hit?

 

I feel very off-topical today!

[+Vinny & Sue Team]

<snip>

All very odd, I must say... And I note that this thread was started only days after that mysterious massive "meteorite" crashed in a remote area of the Andes in Peru...

 

What is the correlation here? And where can I get more info on the meteorite, or whatever, hit?

 

I feel very off-topical today!

The correlation that I was attempting (somewhat humorously) to imply was along the lines of the folowing hypothesis:

...in the days immediately following the fiery crash-landing of the massive "meteorite" in the Andes of Peru near Lake Titicaca (gosh, I love that name...!), the OP appeared on the forum and sent his rather decidedly-odd and misleading post, and therefore it might be concluded that either the thing that crashed (and sickened over 800 persons, according to some reports) contained some kind of extraterrestrial virus-like organism that spreads via the atmosphere and causes odd behaviors (including sending odd and misleading posts) or that the "meteorite" may have really been an extraterrestrial starship, and that the OP may have been one of the alien larval spawn distributed by the the mother ship.

Some links for the Peru/meteorite story appear below, but there are new updates every few hours; you may find them by going to Google News and entering [Peru meteorite] in the search box. Links follow:

 

http://news.xinhuanet.com/english/2007-09/...ent_6755082.htm

http://www.telegraph.co.uk/news/main.jhtml...19/wperu119.xml

http://abc.net.au/science/news/stories/200...7489.htm?health

 

And, for a bizarre editorial from a Pennsylvania-based newspaper that claims that the Peru meteorite strike was predicted by Noatradamus long ago, and that the meteorite bears -- as supposedly also predicted by Nostradamus -- the name of the third Anti-Christ, see the following link: http://www.opednews.com/articles/opedne_ka...us_third_an.htm

Edited September 19, 2007 by Vinny & Sue Team

[+mtn-man]

I feel very off-topical today!

I'm not. Please stay on topic.

[romsk]

My GPSr is designed for the car not for GeoCaching, so when the internal battery runs low there is no way to replace the battery (unless I take the whole thing apart ), so I usually have to call off the hunt and recharge in the car or at home. Being an Electrical Engineer, I was able to adapt my hand cranked AM/FM/SW radio to supply power to my GPSr. With parts from Radio Shack (I didn't want to wait overnight for a Digikey order), I made a simple cable to connect from the radio's power selector switch (by way of a connector I mounted on the radio) to my GPSr. Now, I can power my GPSr from its internal batteries, from the radio disposable batteries, from the radio Nicad rechargeable battery, or by hand cranking! I velcroed my GPSr to the back of the radio (so the radio's built in flashlight faces forward). Now I can crank and walk (even at night) and never have to to worry about losing power again. If you would like more tips on this, please feel free to respond. Or just tell me your tricks in the field!

 

Please note that I am _NOT_ directing you to connect your GPSr to a portable hand held generator or to any unapproved device. But I will give you details on what "I" did in "my particular" application if you are curious. I did not provide all of the details here because each case is different. If you have a good electrical background, you know the circuitry with which you are dealing, and your are confident in your skills, you may be able to do what I did. I have been accused of being a fraud or a spoof on this subject. Those accusations are not true and I took offense to them. So, again, DO NOT ATTEMPT to modify any electronic device unless you know it is possible to do so and what precautions to take.

 

Please vist my Gallery on my Profile page for upcomming Photos on this subject.

Edited September 20, 2007 by romsk

[romsk]

I feel very off-topical today!

I'm not. Please stay on topic.

Thank you mtn-man! I agree, lets please stay on the subject

[+mtn-man]

Closed by request of the original poster.