power leads and voltage drop

[leon]

Hi Guys, I am running a lead to my Camera to power a Dummy Battery set-up, so how long could i go before I have voltage drop consequentially passing low power to the unit.:)

It really doesn't take much power, so would say 5-6 meters be to long. :shrug:

Thank You.

Leon :thumbsup:

[Startrek]

Leon,

Here’s a link to a site which has a voltage drop calculator for DC electrical circuits

https://www.voltagedropcalculator.com.au/index.php?fldlength=2&fldcurrent=0.5&fldvoltage=12&fldcrosssection=0.25&submit=Submit%21

You will need to know -
Voltage in volts
Cable or conductor size in mm2
Cable length
Current in amps

Note: you may have to check in the notes whether cable length is related to only the positive leg or both positive and negative legs , if so double the cable length for a twin + - conductor cable.

Max voltage drop is generally 5% of nominal voltage , so in a 12volt system you can drop 0.6 volts between supply point (battery or SM power supply) and the load or device. Increasing conductor size 1 or 2 gauges usually resolves your Vdrop issues if you dealing with lengths up to 5m or so in a 12v dc system however it’s all dependent on current draw.

Hope this helps

Martin

[RB]

Are you talking about a 240v lead Leon?
If so, then 5-6 meters will be fine.

Even if it's 12v, it should be fine.

RB

[leon]

Thanks Andrew, yes, it is a 240v lead, attached to a Canon Dummy Battery set -up only requiring 7 volts and just on 2amps.

Thanks for the list as well.

Leon

[OzEclipse]

Hi Leon,

Do you mean a Canon DSLR dummy battery?

If I read understand correctly:
1. You have a longer 240v lead running out to a small DC power pack/converter.
2. The power pack/converter says 7V / 2 amps.
3. The DC output of the converter pack goes into the dummy battery via it's own short lead.

The 2 amps on the power pack is a maximum output at 7V. Your camera won't draw anything like 2 amps. If it did, the standalone lithium battery when used wouldn't last more than 40 mins. Even if it was 2A @12V, that is only 160mA at 240v. But it won't be, 2A. It will be a small fraction of that.

So, at that tiny current drain, you can safely use any length of 240V lead, even 2 x 25m=50m is ok, out to the power pack, no need to calculate or stress. Don't extend the power pack lead.

Cheers
Joe

[Startrek]

Leon,
Apologies I was barking up the wrong tree with my reply
When you mentioned “lead” and “camera” I assumed it was the extra low voltage side of things not mains 230V with a domestic extension power lead
Cheers
Martin

[leon]

Thanks Joe, maybe i did read the power pack incorrectly, however thank you for response.

Leon