Light bar: intended for car battery, but....

The wiring instructions do not say how much current the lights use so you cannot use a wall wart until you find out the current it must provide. A car battery is about 12V when it is dead to about 14.4V when it is charging and the engine is running.

 

There are 120VAC-to-12VDC wall warts out there ( I see several on eBay), but you need to know how much current (Amperes) your device draws. I don't see any mention of Amps in the literature you linked.

My general rule of thumb, to be safe, is to use a power supply rated at 4 times the current draw of the device. That way, you won't burn the wall wart out.

 

Sir Mattfara . . . .
Easy peasy . . . . . with that all magical spec of 17.46 watts. Round that off on the upper side of 2 amps and use that current spec at 12 volts.
OR go upwards to 3 or 4 amps if it is to be on for a length of time or you want a cooler running power supply.
( With a long time reliability boost.)
Now in taking that sliding spec of 12------28 VDC is further telling us that the unit is having its own regulator or secondary power supply technology inside to create EXACTLY what is needed for supplying the units LED's.
In that case it will ratiometrically be using less than 2 amps, when being fed at that highest violtage spec.

It just so happens that another magical number of . . . 19Volts . . . falls within that spectrum.
THAT was being the voltage output of myriads of laptop AC power adapter " power bricks" that were used during the 90's-----2000's. They typically had on up into the 3-4 amps at that voltage.
(The light bar will ONLY pull out the minimum amount of power that it NEEDS.)

This smells like . . . FREEBIE ! . . . . if you already have one available to you.
Or a Goodwill-Thrift store-Computer repair shops junque box-Flea market-yard sale might score one for less than the full price having to be paid for a brand new supply out of its shiny new box . . . .ahhhhhhh . . . . . smell that fresh vinyl power cords aroma.

The floor is now open for questions . . . .?
Of course my first one is . . . . .What 'cha doin' to 'dat 'dere passed out dude ? . . . . a la . . . your Avatar.
Exposing his bare back and super gluing a multitude of empty beer cans to it . . . . and then standing by for his sleep arousal time ?
(Then its GREAT SHADES of a stegosaurus time ! )


73's de Edd

 

Sir mattfara . . . . . .

Why 'soitanly . . . .
Those units typically used a plastic " Brick " housing and the majority of the units that I saw, had a plug in AC cord with a small 8 ball shape of AC power plug in.

The DC output then had a length of wire with a connector on its end that was compatible with the DC power receptacle on the laptop.
This was usually having just two wires carring the 19VDC , as the REAL regulation for the power supply was being done within the laptop proper.

You just cut off the wire at the connector end leaving about 2-3 inches at the connertor end . . . in case you ever want to restore that connection.Then its just a metering of the stripped back -separated two wires to ascertain the polarity of each wire and a spot check on voltage .
Then you figure the connection mode to the light bar by viewing its present connector types being already provided ( unless bare wires ) and mate up accordingly.

This adapter is using about 1/2th the physical case size, of my units being seen, BUT its connectors being shown are spot on. Some of them even use a conventional IEC AC power cable.



73's de Edd


.

 

Now I ask you . . . . . doesn't that FREE taste good ?
About he only use I see for those 1990-2000 old laptops is using them for poking up text on or makiing a digital juke box from them.

ASIDE . . . . I still think the best use for empty beer cans , should you find a partaker all passed out , was to convert him to the stegosaurus that I suggested.

The closest I came to cupping was around Tiger Balm Gardens in Hong Kong, but I thought that they were all using same sized "cups".

73's de Edd

 

Sir mattfara . . . . .


All you need to do now is to differentiate as to the light bar or the now questionable conditioon of your free / gifted power supply.
Disconnect the POSITIVE power lead from the light bar and get two test leads with clip connectors on both ends and move out to the olde automobile and lift up the hood and hook up to its battery.
You are already familiar with the time elements and antics withuse of the light bar with the power supply.
You now have a pure 12 VDC power source , with all of the current capability ever needed.
If your problems clear up on battery power, then it looks as if the reality is, of the power brick having a problem.
Imagine the havoc wreaked upon a laptop, by having short time loss of power like that.
If that brick being at fault proves true, possibly the person might yet dig up another supply.
With your new found hook up experience, you shoud be able to connect light bar wiring right to another power supply at the shop for its operational confirmation..

73's de Edd

 

Sir mattfara . . . . .

Tell ya’ what I’m gonna do . . . . . .

I will just tack your connection explanation to the units schematic, just in case you . . .or any others . . . . are up against repairing one of these units.
The HEAVY outer shield cable is the negative connection and the inner shielded line is the +19 VDC output.
Just keep the inner white wire clipped off and possibly insulate its then small wire end from, any external contact.

FYI . . . .
It is being a Dallas ONE WIRE digital buss between this PS and a companion digital interfacing within the computer.
Info is exchanged as well as a handshaking to have the computer showing a connection error being displayed, if this specific HP power supply is not being used with the computer.
You can disregard all aspects of that . . . as you will get your +19, if being connected as I have shown.

Is this a second supply that ‘ole computer guy gave you . . . . with profuse apologies for the first bad ? one, I presume, as you now seem to be his “test bed” .

TECHNO SUPPORT INFO:




Thassssit . . . .

73’s de Ed