I don’t know if anyone will have any idea about this but I have a funny problem with a Laptop (toshiba satellite 5000). When the laptop is on battery mode the output on the mini-plug (ear phone type jack) works fine in my car (I have a special line in aux jack to hear movies and stuff off my car’s speakers). But when it’s powered (plugged in either the cig lighter or the 115V outlet my car comes with [Toyota Matrix]) it doesn’t work. I get a lot of interference and noise.
So I figure it’s the output voltage on the mini-jack. Is there any way to keep the voltage the same as when it’s off battery power? I really want this to work. The mini-jack works fine with head phones (both with and without battery power). Can I make or find a kind of mini-jack resistor that kills the voltage? The manual for the input jack (pioneer deck) states that noise may occur if the input voltage is too high (but doesn’t give me how high is high).
It’s not the audio input jack that’s the problem it’s the stray RF from the notebook’s charging circuit or the car’s output . Since the car does it in both 12V and 115 AC mode and assuming it doesn’t do this indoors I’m tempted to say it’s the car’s power feed, but how to tell? I have the same problem with cellphone charging via the cigarette lighter and radio playing. Other than trying another input scheme like using a mini-stereo plug to cassette adapter for audio input (and this might be noisy too) I don’t really know what you can do.
You won’t accomlish anything at the headphone outlet. Anything that reduces noise will reduce the signal without changing the ratio between them. There should never be a DC component to the headphone output otherwise you’d start burning out the coils. From all indications it seems the power provided by your car has a lot of noise and there is nothing in the computer or power supply to filter it out. Might look into a condenser or capacitor of some kind to reduce the noise level coming from the car’s 12v output.
Well, it can’t be the car’s power feed. I tested that by using the cig lighter of another vehicle to power the laptop to test it.
It could be the power charging circuit. I begin to hear interference when I bring the power plug or mini-jack close to the laptop (say I have music playing and I bring the power plug “near” the back of the laptop I can hear interference starting in my car’s speakers.
The tape player method is what I want to test but I don’t have a tape deck. I’m thinking of an MP3-like player with both in and out jacks. But before I waste my time and money I was wondering if there was a commercially available device to “clean” mini-jack signals and lower it’s voltage.
Shouldn’t RF interference be attributed to distance? I have brought my laptop to it’s max distance possible (about 8 feet) from the car and it’s still making noise. Should I look at testing a lead laptop case?
Hard disk based MP3 players are $ 150.00 to 300.00 and are a lot less expensive risk damage wise than having your notebook bounce around in your car while having it be your car’s MP3 player.
Well, it can’t be the car’s power feed. I tested that by using the cig lighter of another vehicle to power the laptop to test it.
It could be the power charging circuit. I begin to hear interference when I bring the power plug or mini-jack close to the laptop (say I have music playing and I bring the power plug “near” the back of the laptop I can hear interference starting in my car’s speakers.
The tape player method is what I want to test but I don’t have a tape deck. I’m thinking of an MP3-like player with both in and out jacks. But before I waste my time and money I was wondering if there was a commercially available device to “clean” mini-jack signals and lower it’s voltage.
Shouldn’t RF interference be attributed to distance? I have brought my laptop to it’s max distance possible (about 8 feet) from the car and it’s still making noise. Should I look at testing a lead laptop case?
Well, the deck is an MP3 deck. I’m using my laptop as a DVD movie player. On battery it runs about 1 hour 45 mins (just long enough for some movies).
I don’t believe it’s the power but it might be. I bought 3 different power inverters (150 watt, 300 and 600) all say laptops work fine with them. I might try a power bar now to see if that’s the issue.
Would a battery back up clean the output of the 12v? I’m only scared of blowing my alternator with too much drain (it’s only 100 watts on the 115V outlet).