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Extending the 12V DC range


#1

Hello guys,
i was just wondering if anyone knows a simple and effective way to extend the reach of a 12V Dc…

basically i have this Door buzzer that has a camera which is installed outside and the Monitor that goes inside is about 600 meters away… as you can imagine the Voltage to operate the camera is coming from the Monitor which drops and beyond certain range… so i was kind of wondering if any of you hardware gurus know of a way to extend the range of the DC when applied…

remind that the voltage is only applied to the camera when the buzzer is hit…

so basically i would need something that would take for example a 12V DC convert it to AC and Back again to DC (Would that work?) or some other means simpler if possible…

Oh yah and as far the current I’m not sure how much current it requires because none was specified… my guess would be 200mA… to operate the camera…

thanks …


#2

The voltage drop is due to the low voltage and the length of the conductors (longer they are, higher resistance they have => more voltage dropped on them). DC-AC-DC conversion is useless unless you step up the voltage.

So you have 2 options:
-increase the voltage (more complicated and I think more expensive since you need converters)
-increase the diameter of the conductors (so the resistance will be lower and the voltage drop will also be lower) - you could also mount conductors in parallel (think of them as plain resistors).


#3

Thanks godFather89 for the fast reply…

So is there a way to convert the 12DC to 48DC and Drop it down to 12DC again at the end (maybe a voltage regulator at the end)? i mean on the cheap…

as far as increasing the diameter of teh wire if that’s what you mean by Conductors, I’ve tried it with all of the wires available which is basically a Cat5 with 7 pairs of cables so all i could manage to get out of is double each wire and that wasn’t enough…

the other thing i tough about was to introduce a rely that would be triggered by the lower voltage that reaches the end which drops down to 8V DC… and connect another 12 v DC input in the system, but that would push the voltage back to the unit and may damage it, no? maybe i could use a resistor to limit the voltage from traveling the other way) and will also introduce noise in the line speaker and mic…
any other ideas?

thanks.


#4

In this case you need to increase the voltage and lower it at the destination. This way the current passing the wires will be smaller (for the same power demand) so the voltage drop will also be smaller. I don’t recommend using 48V since it’s not safe.

You could use a power adapter of 24V and a DC-DC or AC-DC (depending on the adapter) converter to get the 12V at the destination or 2 DC-DC converters (one to step up the voltage and one to step it down at the destination).

In my opinion the cheapest method would be replacing the wires with some thick ones.


#5

Thanks For your help,
i will look into it and report back…

thank you.