Gps signal to computer

[tertim]

I have a desk top computer running c map and gps connected to computer. All works fine when on shore power but when i power the computer from my inverter the gps signal is lost after about 30 seconds. Can any members suggest a solution?

Tertim

<hr width=100% size=1>

 

[Birdseye]

Its difficult to see an obvious cause but two ideas come to mind. The most likely is electrical interference from the inverter affecting the data cable from the gps to the computer. The second (and some expert may well tell us that this is nonsense) is some form of floating earth. The gps signal is a simple voltage on / off and if there is no off voltage common to both gps and computer I wonder what would happen.

Assume you are talking the same computer in both cases ie you really do take a desktop on board / bring an inverter and battery home.

Another thought. I also run Cmap but via a usb port and serial to usb software. This gives unreliable gps signals unless I connect each time in the correct sequence. Are you going through exactly the same gps start up procedure when you have switched to inverter.

<hr width=100% size=1>this post is a personal opinion, and you should not base your actions on it.

 

[greatspirit]

Inverters puzzle me....most of the electronics in a computer run on 5-9v dc so we take 12v dc from the boat battery run it through an inverter to change to 240v ac (with power loss) then plug the laptop adapter in to the inverter which converts 240v ac to low voltage dc (with more power loss)....?????

<hr width=100% size=1>

 

[Nick_Pam]

Could it be that there is some sort of power saver mode activating on the PC which turns off the USB port/Serial port and thus stops the signal??

Don't take too much notice of this......I work in IT, but I'm not a techie, so what could I possibly know???? lol

Good hunting!!

Nick

<hr width=100% size=1>Byeee...Gone Sailing!!!!

 

[steve28]

try plugging the invertor in on a long lead away from the gps and computer and see what happens.
If its anything like whati have seen before its due to stray rf from the invertor.

steve

<hr width=100% size=1>

 

[galion22]

Sounds Like a power drop off when the central processor starts doing heavy work. This, coupled to the working of the 12 volt fans and ram memory could leave you short of power (as in the supply of amps) although Voltage will still show 230/240 a small power drop off at the source could mean a larger percentage drop off at the motherboard of the computer. Since most modern computer power supplies are capable of delivering a 300watt requirement this is necessary when you consider running CDRom units etc all working together. Well something along these lines anyway.

<hr width=100% size=1>

 

[Guest]

Try GPS Navigator group .....

web-site at my name below ......

<hr width=100% size=1>http://groups.yahoo.com/group/gps-navigator/

 

[Oldhand]

Is your GPS a handheld design with built in antenna? If so, the symptoms you state strongly suggest that your GPS reception is being wiped out by radiated EMI from your inverter. To check, first power up your GPS and go to the satellite reception monitoring display page and wait a few minutes for reception to settle down. Then switch on your inverter (without necessarily booting the PC) and watch the satellite signal levels, if they die in the 30 second period you mention, then the cause is as I suggest. The solution is either change your inverter to a higher quality unit, change your inverter to a decent quality DC/DC converter (more efficeint) or just increase the physical separation of the GPS and inverter. However, the latter may not work as some of the EMI may be conducted by the cabling.

(EMI = electromagnetic interference)



<hr width=100% size=1>

 

[JohnGr]

Seen this before it was the inverter a non sinewave unit which obliterated the GPS signal. Tried screeening and different positions but had to buy a sinewave unit and it cured the problem.

<hr width=100% size=1><P ID="edit"><FONT SIZE=-1>Edited by kimhollamby on 21/11/2004 21:42 (server time).</FONT></P>