12vdc (falling) to 12vdc (regulated)

[hdpete]

Hi,

I have a small electrical device which draws 12 watts at 12vdc and needs to be powered from a 12v battery. Currently, it has a mains inverter from the battery to provide a stable 230vac which is then dropped using the device's power supply back to 12vdc. The device is a portable scanner and so will be very specific as to the input voltage.

There must be a more efficient way of powering this device direct from the battery, but when the battery voltage is dropping (to a minimum of 10.5v), the device still retains as close to 12v as is possible.

Can anyone point me in the right direction of some kind of 12v to 12v DC convertor which can provide a regulated supply on a falling input?

Many thanks for any advice
Regards
Pete

 

[steve-the-hat]

Try doing a search for universal laptop computer car adapters.

These can generally be set for 12 VDC and produce a very stable output. They also come with a wide range of DC connectors.

 

[hdpete]

Try doing a search for universal laptop computer car adapters.These can generally be set for 12 VDC and produce a very stable output. They also come with a wide range of DC connectors.

Hi Steve,

Many thanks for that. This was my initial thought, but do you know whether such a universal charger would still provide a steady 12v out from a falling input voltage (say, down to 10.5v on the lead acid battery)?

Regards
Peter

 

[hdpete]

I found this device: Vanson SDR-150 In Car Laptop Power Supply :: In-Car DC Adapters :: Power Inverters |... which seems that it *may* do the trick. Any feedback gratefully received.
Pete

 

[steve-the-hat]

Yes, quite a few will produce 12 V, even when the input is down to 10.5 V.

Have a search for "Ansmann" and "Custom Power Design".

 

[steve-the-hat]

I found this device: Vanson*SDR-150*In*Car*Laptop*Power*Supply*::*In-Car*DC*Adapters*::*Power*Inverters*|... which seems that it *may* do the trick. Any feedback gratefully received.
Pete

The minimum output voltage of this device is 15/16 VDC, which unfortunately is too high for your application.