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    TDA2005 making static noise

    Hello guys! I want to use a mid-range and tweeter to make a center channel in my car, so i choose to use the TDA2005 plus an active crossover. When i turn the circuit on it has a static noise like, sound like a pink noise to me. So i remove R66/67/68/69 to isolate both circuits, analysing the...
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    How to get better current from LM317?

    I never use the LM317 and this was the first time, i have a NET-MD and old Walkman(cassette) that i want to use in my car, the NET-MD uses 3.0V and the walkman 1.5V, they need about 200ma to work. The thing that i've noticed is that the output of the regulator oscilates too much, at first i...
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    Need sugestions about virtual ground or symetric supply for OPAMP

    Hello guys! I was talking with audioguru some time back about my hafler circuit (schematic attached), it was clipping and i did know exactly why, we exchange some ideas and i choose to let it go. I've never used the center channel and when i did the quality was very bad, the overall sound got...
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    Why is so hard to mimic the Knight Rider scanner Effect?

    Hello All! I've build this "Nite Rider Lights" http://www.electronics-lab.com/projects/automotive/011/index.html http://www.electronics-lab.com/forum/index.php?topic=1427.0 Made a few changes in the project to meet my needs, R3 100R, R2 1K, C1 10uF. By the way, i dont know why i get dragged...
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    Opamp for video component buffer

    Hello there! I wanto to build a video component selector to use with my monitor (SyncMaster 730MP), my idea is to use simple components basically CD4053 / NE555 / OPAMP (buffer). So, with opamp should i use or to be more specific what should be my consideration before i select he opamp. I have...
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    Doubling 7805 regulator current is effective?

    Hello again guys :D My nefiew has a PSP, here we go, so he wants to play games in his father car without running out of battery. I know that there are alot of cheap adapters to do this for about less than $10 bucks, but here at Brazil is not so easy to get this stuff with the same price, and...
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    CD4049 switching failing to switch

    Hello guys! I'm using a CD4049 to make the CD4053 switch change, so you can hold the CD4053 switch position when you turn the circuit on, but some times fail and i have to press the switch button a few times and looks like is not precise, schematic bellow. I have made a few other types of...
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    How to smooth the audio switching pop or spikes?

    Hello guys, long time no see! I've done a audio bypass switch using a pair of CD4053 and a CD4049, the two 4053 are biased with 1M Ohm resistors at the input and the 4049 are build to generate signal to the CD4053. All works fine, no noise (thanks god) but when i change the switches i can hear...
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    How to kill engine noise?

    Hello guys! After building the Surround sound for car and installed in my car i've noticed that there is a engine noise on the speakers, the noise increase decrease when i hit the throttle, i can hear the noise when the volume is down and the ambient is quiet other wise there is no noise...
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    Creating a perfect PCB with toner

    The good thing is, it works very well http://myweb.cableone.net/wheedal/pcb.htm
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    Simple O2 meter with LM3915

    Hello Guys! I'm doing a O2 meter for my car because pay about $150 bucks for a simple meter will not do for me, too much. So, i want to build a meter with 2 LM3915 for better resolution but i have a few questions: 1 - the car voltage is too unstable, there is too much oscilation, mechanical...
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    Surround Sound for car audio

    Hello guys! I was wondering, if i build a "spatial stereo" with the Philips TDA3810 and using my car audio REAR output, could this make the effect of hearing  everyting but vocals and bass in the rear speakers of the car? I think it would be a nice effect to let the front channel to be normal...
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