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Air flow measurement
Hi! For a medical (not life supporting) device we need to measure air pressure and air flow. The device must be low cost. We have found a few pressure sensors which have proved suitable (in the 1-2USD range) for the pressure measurements. We are still investigating a simple and reliable...- yesway
- Thread
- Replies: 5
- Forum: Circuit design
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Passive notch filter needed
Hi! Would be helped by finding a simple (RC based) filter to blank out 600Hz (and later possibly add notches for 1kHz and 1k2Hz) in a design. At this point I have my eyes on tiwn t's or bridged t's, but would like some expertise of what would suit the situation best, I am sure there are other...- yesway
- Thread
- Replies: 5
- Forum: Circuit design
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Strange resonance phenomenon?
Hi, sorry for the not-so-descriptive headline, here is the long specification of the problem: In a car kit handsfree set, there is a 2" speaker and a standard microphone. Both are connected via some circuitry to a cell phone. The whole thingy is housed in a small plastic box, which also...- yesway
- Thread
- Replies: 2
- Forum: Electrical Engineering general discussion
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GSM interference decoupling
We are designing low cost handsfree units for car use and have problems with the infamous gsm interference. The PCB contains simple mic and speaker amps and both pick up quite a good deal of 214Hz hum. Any good general rules would be greatly appreciated. We have tried a lot of basic things like...- yesway
- Thread
- Replies: 4
- Forum: Circuit design
