hmmm then a amplified bazooka tube would work nicely in the back..

 

Just curious what sort of idle current do the amplifiers draw when the car is off?

Has he noticed any 'artifacts' while driving? About once a week or longer, I'll hear a short, ~1 second duration event with a strange series of bleeps from my XM radio. It seems to be associated with ICE shutdown but it is rare and very intermittent. It doesn't happen on every trip and I've not heard it on just the FM radio. If it were Morse code, it would be "dash", "dot-dot-dot".

If it happened more frequently, I'd try to isolate it or put in a C-L-C filter to see if it is coming from the 12 V bus.

BTW, I have seen common mode noise on the 12 V supply IF one floors the car from a dead stop. It also is of short duration and goes away once the ICE is running. Has your friend tried that experiment?

As for no impact on MPG, amplifiers strong enough to dim light reminded me of the old jumping spider experiment. A scientist taught a spider to jump on command and began to remove the spider's legs, one by one. Even down to one leg, the critter tried and managed a weak hop. When the last leg was removed, the spider no longer jumped so the conclusion was: legless spiders are deaf. . . . So your friend still notices his MPG?

Bob Wilson

 

I haven't tested current, but I will do that and let you know. We have (but no longer need it setup like this) the active crossover on constantly, as well as the LCD screen, but it shuts off most of it's circuitry when the comp is off. It will drain the battery in a couple days, so we'll be changing that soon.

Haven't noticed any noise from the car at all. We had some computer processor noise leaking into the audio signal from the motherboard's on-board sound, so now we use a USB 24 bit sound card and there's none of that noise. We aren't using the car's built-in stereo at all, it's completely independent. The car's sound can be run through the computer and amps as a line-in for listening to the radio at the drive-in.

He notices his MPG and even does P&G but I think he stopped posting mileage here when it became a chore converting the kilometerage by hand.

 

Tested the current when everything is off the continuous draw is 290mA... that includes 2 things* that are fully "on" and shouldn't really be. Once we fix that up I'll test again.

Devices on this circuit:

-Active Crossover*
-Subwoofer Amp
-4-Channel Amp
-Mini-ITX PC (12v PSU)
-LCD Touchscreen*

 

Owch! Glad you found it before the battery died.

Bob Wilson

 

As for no impact on MPG, amplifiers strong enough to dim light reminded me of the old jumping spider experiment. A scientist taught a spider to jump on command and began to remove the spider's legs, one by one. Even down to one leg, the critter tried and managed a weak hop. When the last leg was removed, the spider no longer jumped so the conclusion was: legless spiders are deaf. . . . So your friend still notices his MPG?

Bob Wilson


LOL well said..

 

The battery has died in a 1.5 day period from that much drain, definitely need to solve it.

Another thing we're probably going to do is put some gel-cells into the compartment on a relay (or two) so the computer and amps can be run without risking the car's accessory battery. We had that kind of setup in his previous car and it worked great (except we used a regular car battery and learned the hard way why that's a bad idea ) It's not the end of the world in a Prius II since you can jump the 12v but running it down still kills the battery, or you can have the car "on" but not started so that the 12v gets charged from the HV, although you'd want to be careful how low you let the HV get before letting the ICE start. Either way the extra 12v battery will keep the extra electronics from interfering with normal operation of the Prius when the car is off as long as there's isolating relays.

We've been experimenting with putting computers in his cars for a little while, starting with the Chrysler K-Car... http://thiscar.doesntexist.com (news is never updated, I'm too lazy )

 

You might consider using the cigarette lighter circuit to operate the isolation relays. In the 03 Prius, it is controlled by the ignition switch.

When I put in my UPS remote switch, I used this circuit so it would automaticly switch it off the inverter when the car is shutdown. It is wired with a manual switch since I don't need 110 VAC all the time. Still, we have a couple of small dogs and I have found the inverter turned "ON" a couple of times already but the battery has yet to die.

Bob Wilson

 

We've got the "accessory" signal coming from the cigarette lighter in the center storage bin, but I think the other cigarette lighter socket in the dash is on the ignition circuit, from what I remember having my laptop inverter plugged in.

My friend went down the the US to help his cousin put a computer in his Prius, and he left his car with his sister, but I guess he forgot to tell her to take the car for a walk every day because she ended up having to charge the battery... I saw this coming and told my friend to tell his sister that she needed to take the car out every day... ah well... gonna fix that as soon as he gets back. I bet his poor battery is already down to 50% capacity.

 

The dash board cigarette lighter was the one I used. Mine is an 03 Prius and I don't remember a cigarette lighter plug in our center console. It doesn't matter because now I have a remote ON/OFF and 110 VAC outlet from the inverter in the trunk.

Bob Wilson