AC Power Adaptor Pinout // Adapt to battery power

[james211]

I have a monitor I use for work (motion/photo) and I'd love to be able to use it with my cine batteries which are 14.4v / 12amp batteries. There is a company that makes a special adaptor but its $700, I have to believe this can be worked out for cheaper.

The monitors power supply is rated 19v 180watts with 6 pins. Thankfully the AC adaptor has a Lemo connector so I was able to figure out the pinout, see attached. I'm guessing its 3(+) and 3(-). There were only four wires, but the red and white were soldered to two pins each, while the yellow and black had their own pins.

So what would be the best way to tackle this? I was going to start by connecting two batteries in series and then use a DC to DC converter to get the voltage down to 19v. I could do this through a cheap converter from amazon, but I'd like the power to be as clean as possible. Does anyone have any recommendations? I'm pretty technical and handy, I can solder surface mount and through hole, build PCB's in Eagle, but I don't have much experience with electrical engineering on the technical side.

The power supply that comes with the monitor is an Adaptor Tech STD-19063

 

[Delta Prime]

If you wish your monitor to run on batteries for 1 hour then you're okay.

180Watts÷19Volts= 9.474Amps
That's how much current your monitor draws from your batteries which are rated at 12Amps.
Batteries in series will increase the voltage but the current remains the same.DC to DC converter, (buck converter) a higher DC voltage to a lower DC voltage, although very efficient will not help you. Your monitor will last maybe 1 hour on batteries.

 

[james211]

What are your thoughts on using something like this?

12V to 19V 10A 190W DC-DC Boost Step Up Power Converter Voltage Regulator Module

Larger Selections with Deep Discount on Vehicle Parts, Accessories, and More!

www.madhornets.com

I don’t need it to run constantly, just 15-20mins at a time, plus I have a lot of batteries.

 

[Martaine2005]

What are your thoughts on using something like this?

12V to 19V 10A 190W DC-DC Boost Step Up Power Converter Voltage Regulator Module

Larger Selections with Deep Discount on Vehicle Parts, Accessories, and More!

www.madhornets.com

I don’t need it to run constantly, just 15-20mins at a time, plus I have a lot of batteries.

I reckon they are fiddling the output figures.
Maybe at a lower voltage, the amperage is higher.

Martin

 

[Delta Prime]

That's a boost converter.
You could go either way but you're towing the line. If this is how you make your living. I would heed
@Martaine2005 warning. That heatsink is going to be smoking Hot.
I would double the current capability 20 amps.

 

[james211]

That’s the thing, I’m looking for a solid solution that will not fry the monitor, but also doesn’t cost 700. I’m fine paying half that if someone can help me find a solution.

 

[Delta Prime]

I believe you know what you're doing, you're Idea sounds good to
Me. But I can't recommend a product for you. You're on the right track double the capabilities as far as current, wattage is concerned
Buy from a reputable manufacturer.

 

[james211]

Ha…so what you’re saying is, spend the $700…

 

[kellys_eye]

180Watts÷19Volts= 9.474Amps
That's how much current your monitor draws from your batteries

Probably not. The PSU will be 'over-rated' for safety reasons and potentially rated at what it is only because they used it from another device rather than designing one from scratch. For example - my laptop PC power pack is rated at 65W but the laptop itself needs far less to work.

Measure the ACTUAL current it runs at.

A standard boost converter will do the job, suitably over-rated as mentioned above. There may be a reason why the extra wires exist though so be prepared for some funny happenings if the basic 19V really needs some extra signal that the other wires provide.

 

[kellys_eye]

That’s the thing, I’m looking for a solid solution that will not fry the monitor,

Provided you keep within the voltage rating and the PSU can deliver AT LEAST the required current (you can have a higher current supply, the equipment will only take what it needs, no more) you won't fry anything.

 

[Delta Prime]

Ha…so what you’re saying is, spend the $700…

Ha.... what? What I am saying is I am on your side! That unit cost $39.89 or some crap like that spend 50 bucks.
Follow @kellys_eye 's recommendation, that Eye never
Blinks,kind of spooky.

 

[Martaine2005]

Have you opened the monitor and checked the working voltage?.

Follow @kellys_eye 's recommendation, that Eye never
Blinks,kind of spooky.

hahaha, that’s funny

 

[Martaine2005]

If you have plenty of batteries, parallel two or three of them to increase the current by two or three times. Remember, you can’t get more than you put in (minus losses). 8 or 10 batteries in parallel, 8 or 10 times the current = 8 or 10 times ‘run time’.

Martin

 

[james211]

sorry, I misunderstood your statement @Delta Prime. @kellys_eye i have to be honest, with this kind of six pin connector I’m not sure I know how measure the actual current. What would you suggest?

I think I’ll order that $40 converter and see what happens. I’ll plug in into my bench supply and test the voltage before plugging it in. That will also allow me to play with the current a bit.

 

[Martaine2005]

Put your meter in series with the supply wiring. Also remember to change the probes to Amps connections.’

The kind of connector you have with parallel wiring is typical of using’in house’ components already bought and re-using them. Or a few are used to save pennies from altering input stages on the PCB. All said and done, the connections across two pins deliver the same signal regardless.

Martin

 

[james211]

okay, I'll have to figure out how to put it in series, I've don't it before with other things, but not finished cords might have to desolder something, for some reason I was hoping for a better option.

 

[Martaine2005]

If you have a clamp meter, you can use that at each connection.
Failing that, sounds like an ATX PSU with thousands of wires all coming from the same point on the PCB to simply be distributed.

 

[Delta Prime]

for some reason I was hoping for a better option

How about hiring a tech who knows what he's doing!
Oops sorry that's you. Yeah, clamp on meter way to go. I'm afraid you just might hurt yourself. Research how to use a clamp on meter "Only one wire."

 

[Martaine2005]

How about hiring a tech who knows what he's doing!
Oops sorry that's you. Yeah, clamp on meter way to go. I'm afraid you just might hurt yourself. Research how to use a clamp on meter "Only one wire."

@Delta Prime
Sometimes I think you are a breath of fresh air. Other times you stink

 

[Delta Prime]

@Delta Prime
Sometimes I think you are a breath of fresh air. Other times you stink

You're absolutely correct! That was a stupid comment.
I'm not deleting it.
I'm leaving it,to remind myself I could be a real jerk.
My apologies @james211.