Screwfix 12v to 250v inverter

wishbone

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Has anyone tried 150w screwfix 12v inverter..for use with tosh-sat laptop....charging 4 AA cells for garmin 48 gps...various other charging upto 150w

please help asap need to get one before w/end or suggestions for another type

Many thanks
 

hightech

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Why mess around converting from 12 volts to 240 then back to probably around 19 volts to charge your laptop.

Go to maplins or similar and buy a 12volt laptop adaptor, stays at DC all the time and uses a fraction of the current that would go to heat converting up and down.

Also removes the temptation for the ladies to plug their hairdryer etc in!

Hightech
 

cliff

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[ QUOTE ]
Has anyone tried 150w screwfix 12v inverter..for use with tosh-sat laptop....charging 4 AA cells for garmin 48 gps...various other charging upto 150w

please help asap need to get one before w/end or suggestions for another type

Many thanks

[/ QUOTE ]These little invertors tend to be square wave and while fine for running a filiment bulb do tend to damage chargers or the associated equipment.

Either go for DC/DC convertors or a good sinewave invertor ( or at least a modified sinewave invertor) To date I have knackered several items running them of a little cheap invertor. Now running a 1.8kw cont (3kw peak) pure sinewave invertor without any further damage to equipment
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“I’m as confused as a baby at a topless bar. “
 

wishbone

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Thanks, I need to charge 4 x aa's from 12v have looked at maplins but cant find anything! am going to buy a 4way cigar adaptor and a 12v inverta for laptop and use one of the cigar sockets for me garmin 48.....dont laugh but I need to charge me toothbrush which plugs into 240 or 110 ac! or 12v to 240 ac inverta! will look for a sine wave type.
 

William_H

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To charge 4XAA from 12 volts you need a battery holder from Maplins and a resistor of around 120 ohms rated at 1 watt. This connected between the positive 12 volts and the battery pack positive. The negative of the 12 volts and battery pack will be connected together. This rsistor will give 50 milliamps charge current suitable for long term smallest AA rechargeable NiCad. recharging over 14 hours. If you make the resistor 60 oyhms then the current will double to 100 milliamps and this will be more suitable for larger capacity NoiMh batteries. If your device has a recharge socket for a charger less than 12 volts then if you get the right kind o0f plug you can recharge from 12 volts using a suitable resistor. ie if 4 AA then use 120 ohms if 2AA then use 180 ohm resistor. The best bet being to use a multimeter on current range to measure actual charging current which should be 10% of rated Amp hour capacity of the batteries. (for long term charge) (ie safe if you forget to turn it off) for shorter charge time then 100 or even 200 ma is OK but don't leave it on. Good luck olewill
PS if you are happy with 50 ma charge current you can get a high powered LED suitable for 50 ma and wire in series with the resistor to indicate that it is charging. or fit an ordinary low power LEd in series with a 120 ohm resistor in paralell with the original 120 ohm resistor to indicate charge current.
 
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