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Gear / Technical Help => Remote Power => Topic started by: H₂O on March 17, 2008, 07:16:25 PM
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May be old news:
http://www.sounddevices.com/notes/recorders/powering/power-draw/
Note this is only for a 744t -> Would think other models draw less (i.e. 702 fer sure)
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In plain English...does anyone know how long the 744 will run on a L-type 4600mAh battery with phantom power, running with the backlight and LED recording to both HDD and CF all 4 channels?
also need info for my 7600mAh battery. I know I got at least 3 1/2 hours with no phantom running with with the lights on 1st set and periodically on during 2nd set.
I figure rather than me doing test runs at home, someone should know how long this thing will last with all guns blazing. I've only used it in the field twice and once I ran it with the AC cord, so I just have no idea.
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According to the results on this web site the closest I see is:
744T:
no battery,
2 mics with phantom power (48V) it pulls 12W
At 7.2V this would be about 1.66666A
So a 4600mA Internal battery should last about 2.7 hours
This is a rough estimate as the original W are based on 12V External
Note that the Backlight is off and LEDs at 50% brightness
According to page 56 in the 744T manual (v.2.40)
Power consumption for 744T is 4W - 20W @ 12V
Mic's draw 1W each w/ 48V on
Sample rate draws 1W each time Sample Rate doubles
Hard drive is 2W
Active inputs pull 1.5W each
Battery chargeing approx 10W
4 inputs 96Khz Phantom on 2 recording to HDD = (1.5 x 4) + 2 + (1 x 2) + 2 = 12W
Assume switching regulators used and very efficient
Assume internal battery averages at 7.2V
Assume Sample rates using following Watts (1W = 48Khz; 2W = 96KHz; 3W = 192KHz)
12W / 7.2V = 1.6666666A = 1666 mA
4600mAH battery / 1666mA = 2.7 hours
7600mAH battery / 1666mA = 4.56 hours
No idea what the backlight pulls
702 on same math:
2 inputs 96Khz Phantom on 2 recording to Flash = (1.5 x 2) + 2 + (1 x 2) + 0 = 7W
7W / 7.2V = 0.972A = 972mA
1800mAh battery / 972mA = 1.85 hours
4600mAh battery / 972mA = 4.73 hours
7600mAh battery / 972mA = 7.92 hours
Again these are rough estimates
I got about 2 hours 50 min on a 1800 mA running 2 inputs at 96Khz; no Phantom; no back light; recording to Flash on 702 so the numbers runtime hours above seem a little low to me
1800mAh / 694mA = 2.59 hours