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rando · 05-14-2004, 03:11 PM

Hmmm ... maybe I'll try moving my RCA cables around a bit and see if I can eliminate the little bit of noise I have before I go the expensive USB/Sound route. Then again, bringing the USB sound up front will shorten the run I need to use for my Microphone (once I get it installed). That could be a plus too, I guess.

As for the standby power issue, i just completed taking some measurements. My truck uses 19-25mA (measured at battery ground) when at rest (given a few minutes to stabalize before taking the measurement). The Opus draws about 6.7mA on the 12V line with ACC low and the computer disconnected. The computer and opus together pull 96.7mA with the computer off (measured at the 12v line into the Opus). I have an unpowered USB hub connected to my GPS and touchscreen. If I pull the USB connection, the combined power consumption goes down to 92.5mA. I pulled my serial RadioMan, the RCA cables, and the VGA cable. These had no measurable effect on the current draw. So here is the power consumption of my system while off.

04 4runner Engine/ACC Off: ~20mA
M10k (Off with no devices attached): ~86mA
USB Hub and devices (Computer off): ~ 4mA
Opus (Off with no devices attached): ~ 7mA

Based on this data, I can expect my battery to drain 5-6 times faster than it would have without this equipment. If I want to address this problem, it looks like the only approach is to kill the 12v line into the opus when the truck is off. This should be doable with two relays or a single relay and 2 diodes. I'll probably go with the former solution since it guarantees isolation between the 12v input and 12v output of the Opus.

05-14-2004, 03:11 PM	#18
rando Raw Wave Join Date: Mar 2004 Location: Redondo Beach, CA Posts: 1,969	Hmmm ... maybe I'll try moving my RCA cables around a bit and see if I can eliminate the little bit of noise I have before I go the expensive USB/Sound route. Then again, bringing the USB sound up front will shorten the run I need to use for my Microphone (once I get it installed). That could be a plus too, I guess. As for the standby power issue, i just completed taking some measurements. My truck uses 19-25mA (measured at battery ground) when at rest (given a few minutes to stabalize before taking the measurement). The Opus draws about 6.7mA on the 12V line with ACC low and the computer disconnected. The computer and opus together pull 96.7mA with the computer off (measured at the 12v line into the Opus). I have an unpowered USB hub connected to my GPS and touchscreen. If I pull the USB connection, the combined power consumption goes down to 92.5mA. I pulled my serial RadioMan, the RCA cables, and the VGA cable. These had no measurable effect on the current draw. So here is the power consumption of my system while off. 04 4runner Engine/ACC Off: ~20mA M10k (Off with no devices attached): ~86mA USB Hub and devices (Computer off): ~ 4mA Opus (Off with no devices attached): ~ 7mA Based on this data, I can expect my battery to drain 5-6 times faster than it would have without this equipment. If I want to address this problem, it looks like the only approach is to kill the 12v line into the opus when the truck is off. This should be doable with two relays or a single relay and 2 diodes. I'll probably go with the former solution since it guarantees isolation between the 12v input and 12v output of the Opus. __________________ 2004 4runner Last edited by rando; 05-14-2004 at 03:14 PM.