View Full Version : bu-353 dropouts using inverter

15th February 2010, 10:36 AM
About 6 months back I purchased a new 10" netbook, ozi and usb gps for incar nav. Whenever I am moving with the netbook on the inverter, the gps drops out. Strange though as when I'm stationary it has no issue. Played with a few settings and still no real idea whats happening. If I remove the usb, reinstall and restart moving map the process repeats. No issues when not on the inverter. I was just curious if any others have struck this type of issue previously to give me some insight into what maybe happening.

With thanks,


Wahroonga Farm
15th February 2010, 11:20 AM
USB connections are notoriously unreliable.

Can u simulate by wiggling the netbook usb connection?

16th February 2010, 01:18 PM
USB connections are notoriously unreliable.

Can u simulate by wiggling the netbook usb connection?

Hi and thanks John, in short to your Q- No. Unfortunately the only drop out I get is when using the inverter and being mobile. No probs mobile whilst not on the inverter either. It is not a problem with the physical usb connection. Still interested if any others have experienced this issue previously.



Wahroonga Farm
16th February 2010, 02:32 PM
Is this a 12 to 240v inverter to normal Lappie PS?

Wot inverter brand/ power? I run a **** Smith 300w modified sine under the passenger seat no problem to an eeepc.

A Jaycar 12v to PC converter style of supply may be a better choice?

16th February 2010, 02:34 PM
May I suggest you connect the inverter to something else, run the laptop on self power with the GPS connected and see if it is the Inverter producing spurious RF noise affecting the GPS reception.

16th February 2010, 03:57 PM
John, yes the 600W/1200peak psw inverter (brand unknown, Melbourne supplied) is powering the Lenovo S10 via the ac charger. And a good point Nicko, I was wondering if there was any interference produced on the output waveform, Anyone got a cro? I will do as you rightly suggested on the way to work tonight to see if I can get a dropout when the inverter powers something else and report back my findings. Interestingly though, why would it only drop out whilst mobile? sort of counts out the spurious emission's theory.


21st November 2010, 06:54 PM
i think we should estabish the how its all done first..

it could he the cig lighter plug or socket in the car where the inverter is connected to

lets do this.....
1) wire and + and - from the battery direct to the inside of the car
2) place a 10amp fuse (slow blow) on the wire +
3) solder the wire direct to a brand new 12v heavy duty cig lighter socket
4) make sure our inverter plug is nice fit and if too cheap looking upgrade it to stronger one with good fuse
lets say 10amp here too but fast blow

THAT should provide solid + and - to the inverter direct from the battery

now lets make sure the lappie power plug is fine...
if in dought ..replace it with a clear one..for visual a ok :)

make sure the power in plug to lappie is good ...
lappies get sloppy in the power in and out socket..
check socket and plug...

NOW that should then ok...all power to lappie

(always make sure the lappie is fully charged before your use)

if the lappie has good solid usb and gsp usb is tight fit you feel as slight drag as you insert and remove if you dont you ssee the lugs that provide this bend then in tighten..best you do :)
without replacing..
that will sort all bump de dump issues..

i 4wd with a lappie playing dvd's and get away with it ...on landcrusier troopy
so it can be as stable as..

make sure nothing in cables department is goin to pull..:) from movement.

the power you got is way fine.....really

if you wish to test its draw off and power use in watts
here is a cheap way

for $30 buy a product at ideas@todae.com.au
which is power meter..but its like a power on and off timer..a 240 plug in...
place that in the lappie 240v input where it meets the converter..
that will confirm draw off..and you can check its stability...

thats ,,my spin on what i would do
hope that helps you



22nd November 2010, 10:01 AM
John, yes the 600W/1200peak psw inverter (brand unknown, Melbourne supplied) is powering the Lenovo S10 via the ac charger. And a good point Nicko, I was wondering if there was any interference produced on the output waveform, Anyone got a cro?

I've seen some very messy spikes from MSW inverters when powering laptop SMPSs, but haven't put a CRO on a PSW inverter.
I'm not a fan of running laptops from inverters, a much better option is a DC-DC converter. Jaycar sell decent ones at reasonable prices.

Just a thought, is your laptop seeing sporadic power interruptions when running off the inverter? Set your laptop to do something obvious on power change, i.e. play a sound when switching from AC to battery.
The inverter may be cycling on and off due to changing load from the lappy, and it might be resetting the USB bus on each switch?
You could try plugging something else into the inverter as well that will draw a constant load (I use a soldering iron for this, but might not be safe while driving) to keep the inverter chugging along and delivering a stable supply to the laptop.

It could also be something like interference from your alternator/air con/HID lights etc getting into the inverter's front end and de-stabilising the sine wave?

22nd November 2010, 09:07 PM
yes i of the view that dc to dc is better and safer.

inverter is an option...and the festy is true..some need a dummy load on them ...when using really small draw offs..if they have feature..
to keep even flow...

i think when dealing with dc to dc small wattage and converting it
its good to get away from noise and feedback from the drawing power dc from post alternator
by drawing direct from a 12v source..
by filtering your draw off
by fuse protecting it as well

there are some inline dc to dc converting..
there is some kits
there is dc to dc product.

i think that the highest risk has been from el cheapo plug converters/adapters....like the supplied cable and plug...
often they overheat
and they ment to proform the duty cycle ment

some of this stuff was not ment for long play
a dummy load like a light bulb would do...
maybe since its in a car...a fan?
a useful dummy load :)

i say you have some greaqt points to start from
we all be interested to hear for nut it down and let us know :)
good luck


23rd November 2010, 10:09 AM
Excuse my ignorance but why can't you use a 12v cigarette lighter plug to power the laptop?

I have a Dell 10" netbook with the BU-353 running Oziexplorer. I recently purchased a 12v adaptor (from eBay) that plugs into the cigarette lighter and seems to power the Dell quite well ....

23rd November 2010, 07:49 PM
thanks for the question...

electronics are touchie things...ideally a lappie was built for the purpose of limited mobile access...

clearly we dont follow that useage...2hr running time and switch off to recharge

we also dont follow the concept direct battery powered dc current feed for the laapie via its onboard plug in battery pack.

to those with lappie use will know when you feed 240v recharge
feed to the laapie with the battery in...
you can often hear the hmmmmm in the soundcard...

because the earth and power feed...

this means 240 v feed has a noise effect.

we get a noise effect when using 12v taken post alternator
which the 12v cig lighter is...
its also prone to spiking and browning...
but its main deal if noise.

now in some cars...a 10amp cig lighter is really more amp protection than the wires going to it can handle
cheap wired cars !

some are not even 10 amp there 7.5 or even 5amp...
this is problem when we piggy backed the socket or maker did
and has 10 amp sig lighter on the same line or less amp..
and multi users in the car plug in...
mp3 here
phone recharger there
inverter here
reverse camera monitor there
12v heater or cooler esky..

SO to avoid the possiblities in a general sense...
running a 20amp wire line with 10 fuse or 15amp direct to the battery..with a suppressor right at the battery
gets you as good as you get from that set up...

of course dual 12v car battery system with independant issocalition and pulling the feed point from the distant battery is better

and battery on its own ...connected to a sockets ..that you charge seperately..so in other words not linked to alternator...
and you have sockets from that...
gives the best clean dc to dc...
think of it as major enduro lappie battery...

some cheap and nasty plug adapters converters...
have apart from noise issues as mentioned...
heat issues...
because the units have little if any heatsinking
i seen some that do..and because of their size and uglyness ..often dont get bought..slim...sleak ones do..and small slim and sleek...are the highest risk..of overheat..

the other side issue to this is cheap and nasty version of any are ..cheap and nasty...
and prone to a short life..
often have poor protection factors
and that means they kill the cable/plug..blow the cig socket..
blow car fuse and relay
and blow a item or items connected

the points made are to cover all the possablities..

and yes you light have bought a good one ..and might last a while..and never risk anything..
and yes it works..

but now your away of the risks and failures and the reason behind people doin the same job a different way...
i hope that gives you a better understanding..
we take electronics as a given...
and often risk them...

i hope this helps clear things...:welcome

23rd November 2010, 08:53 PM

I dont think I followed any of that.

A laptop is not fed 240 V AC, its fed with a DC voltage (usually 17 to 20 VDC) from a transformer rectifier power supply. In car adaptors convert 12VDc via electronic wizardry to the required 17 - 20 VDC. As long as the adapter can supply the required current, all should be good..

23rd November 2010, 11:25 PM
well regardless of what feed voltage you give the lappie..be it 17v-20v
by the magic 240 lead with super gizzzmo (step down transformer) to convert it from 240vac to 12-20v dc
the discharge from it is heat / and noise
from the process and by products.

runs on 12v and 5v inside.. same as your desktop pc !

it likes its 15vdc---20vdc noise clean, ripple free and cool and stable!

the extra voltage is not just to overcome loss but it used to RECHARGE the battery in the lappie..:)

a 12vdc to 15-20v dc has the same issues (its a step up transformer ) so has heat and noise as a by product..
and the cost to make 15vdc -20vdc from 12vdc
is battery amps !
it costs more 12v amps to make 15-2-vdc amps
thus its a drain on the battery of a car
and within hourse could drain a car battery out to below its starting amp requirement

the point is here is redue the heat and amp lost and with it noise !

reduce the loss in conversion of step up or step down to maximize indurance of supply and to again keep heat and noise
out of the feed voltage!

noise free.....

we call this regulated voltage..

that is what a battery in the lappie does
so if we alterative feed it ...we try to achieve the same

12v cig lighter dc feed are full of noise
and full of voltage flutter
they can be 11.8v-------14v
if they goy cheap and nasty supply line to the cig lighter..
they get heated...hot when in use
and adapters dont like any of this
and neither do lappies

its not just 12v in 15v out ..then 15v in and 12v used
in the case of 12v dc to dc convertor then lappie itself..

battery power stays at 12v until its amps drop then its voltage drops..

but this takes hours...if we just look at the lappies drain...

so i hope i have explained the facts....clearly with this add on...
purity of volts and regulated voltage and amps is whats needed
cig lighter points dont give you that to start with..which effects the adapters and thus the lappie
to get as good as you can get you need go to the battery direct
and a battery which does not have any inputs of heat or noise is best.

the 240v came in cause people use this...from 12v to make 240v..to use an adapter...to convert it all back...
a silly way of adding undue heat and noise and lack of stability

the post started..with the use of a converter!
240vac from 12vdc
to then plug a lappie 240v lead in to make 15-20vdc to feed a lappie

as you can see the long long long way...
and a way with lots of losssssssssssss
and lots of noise\
and lots of heat
and lots of trouble when stabilty starts to waver