12v AC/DC adapter re wire question

[heym123]

Hi there all, I have a question.



I've just purchased this repeater:




Technique Specifications:
Item Specification
Up Link Donw Link
Frequency Range 890MHz ~ 915MHz
1710MHz ~ 1785MHz

935MHz ~ 960MHz
1805MHz ~ 1880MHz

Power -70 ~ -40dBm/FA (1.23MHz)
Gain 60±3 Db 65±3 Db
Max Output Power +23dBm / ±3dBmTotal Power +23dBm / ±3dBmTotal Power
Impedance 50Ω
Power Supply AC 110/240V (used AC/DC Adapter 12V dc)
Seclusion >70dB
Compact Design Indoor Use
Item Diemension 240 x 180 x 20mm
Connect Mode N connector
Ambient temperature -10°C~60°C
LCD display function
can display signal strongness which it receives from outdoor antenna ,
the signal bar will be full black if the signal is received very good.




The unit itself says 12v DC, but the actual power supply looks like it inverts AC>DC. I was trying to work out if there was a way I could hard wire this straight to my 12v battery bank in my motorhome?



The idea I had was to go straight from the battery terminals with an inline fuse, snip the end of the supplied adapter and rewire this to connected battery line.



Am I on the right track here? I am a complete electrical novice so please excuse my ignorance.



Much appreciated!

 

[Richard Burns]

The unit should work OK from a 12V battery as you describe.

Be sure that you are complying with the Ofcom requirements for mobile signal boosters.

 

[westward10]

Welcome heym, there should only be this thread running now.

 

[heym123]

Hi sorry for the double post!

The unit would only be used in European countries where there are no restrictions in place.

What in line fuse and gauge of wiring would you suggest to be safe running this unit directly from the 12v leisure battery?

Also from the specs above what sort of ah draw would you expect from this?

Again thanks for the responsiveness!

 

[heym123]

The unit should work OK from a 12V battery as you describe.

Be sure that you are complying with the Ofcom requirements for mobile signal boosters.

Just some more details on the supplied adapter

'Input AC100-240v 50/60Hz'
'Output 12V --- 2A'

So would buying some 11Amp automotive cable with a 3Amp inline fuse be sufficient?

Many thanks

 

[DPG]

Should be fine. Although the psu inrush current may be high enough to pop a 3A fuse. May have to increase it slightly.

How long will the cable run be?

 

[heym123]

Should be fine. Although the psu inrush current may be high enough to pop a 3A fuse. May have to increase it slightly.

How long will the cable run be?

Thanks for that, up it to 5A then? The cable will run around 1.5 meter

 

[DPG]

Should be fine. Volt drop shouldn't be an issue either.

 

[heym123]

Should be fine. Volt drop shouldn't be an issue either.

Brill. Final newbie question...

This particular unit doesn't have an on/off switch. When pulling the power connector out of the unit will this still draw a residual current off the 12v battery? If so, would it be worth popping a rocker switch into the circuit to avoid so (obviously looking to conserve as much of my leisure 12v power as possible)

Thanks!

 

[DPG]

There's no residual current if you have unplugged it. Unless I've misunderstood something.

 

[heym123]

There's no residual current if you have unplugged it. Unless I've misunderstood something.

As you can tell I am learning much as i go along, such as these basic concepts.

You've been super helpful DPG. Appreciate your time and help

 

[DPG]

No worries. If I ever have an antenna impedance matching problem I know where to ask!