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Post by the light works on May 23, 2018 13:37:02 GMT
Never saw that. Looks like something that would be real handy in your line of work. And $60 isn't bad at all if it works like they claim. Too bad they don't have one for iPhones. FLIR is another smart-phone product that you could probably make use of in both your lines of work. But it's rather on the pricey side. www.flir.com/products/flir-one-pro/the cat s-60 has it built in, but it's a $600.00 phone. |
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Post by c64 on May 23, 2018 18:02:47 GMT
The app on my iPhone detects the magnetic field but not the electrostatic one. Most non-contact voltage detectors sense the electrostatic field. I don't know what the Android phones detect but I suspect it's also the magnetic field. they use the compass module in the phone. they may be able to tune it to pick up 60hz AC, but apparently they don't have it yet. The compass module can only detect a current, not a voltage. The telephone engineers use a probe to find phone lines or identify terminals. This probe is basically a small antennae hooked to the gate of a very sensitive FET transistor. The transmitter is nothing but a pulsed DC generator emitting an alternating or constant frequency. When the probe is held near the line with the transmitter attached to, you can hear the tune of the transmitter. This allows you to locate and follow telephone lines inside walls and identify the terminals inside a distributor box. This also works quite well with the mains frequency. The telephone probe is very good in detecting life wires inside a wall or to check if a wire is life before you cut it. Picking up 50 or 60Hz noise is way too easy. In fact network cards and most RF receivers come with a bandgap filter for the mains frequency in order to make them work reliable in an urban area. Even cell phones have great difficulty to get rid of this noise in order to work properly. If you use your cell phone for audio recording, you might notice that it is bad in picking up the humm of a transformer. Since the phone can't tell if this is real noise picked up by the microphone you want to keep or "junk" received over the PCB wires or through the charger, the phone will supress this frequency. So there are two likely ways for the app: 1) Record audio with disabled filter (or tuned to the wrong frequency like EU instead of US) and detect the humming noise 2) use the FM tuner like a SDR (Software Defined Radio). You can use a cheap DVB-T USB receiver to receive almost anything. Most of the DVB-T devices contain a Realtech chipset which uses an 8-bit ADC to measure the signal strength for auto-tuning. This chip can be pushed to up to 8MHz sample frequency. A SDR software then can use this data to convert the strength signals to map the frequencies it contains (just like MP3 does). This allows to listen to any RF signal up to 4MHz. Since most of those DVB-T devices are equipped with a wide-band tuner, you can multiply the frequency range. A common international DVB-T device which contains the Realtec chip and a Phillips wideband tuner can let you listen to anything between a few kHz up to 2GHz. |
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Post by the light works on May 23, 2018 18:15:54 GMT
they use the compass module in the phone. they may be able to tune it to pick up 60hz AC, but apparently they don't have it yet. The compass module can only detect a current, not a voltage. The telephone engineers use a probe to find phone lines or identify terminals. This probe is basically a small antennae hooked to the gate of a very sensitive FET transistor. The transmitter is nothing but a pulsed DC generator emitting an alternating or constant frequency. When the probe is held near the line with the transmitter attached to, you can hear the tune of the transmitter. This allows you to locate and follow telephone lines inside walls and identify the terminals inside a distributor box. This also works quite well with the mains frequency. The telephone probe is very good in detecting life wires inside a wall or to check if a wire is life before you cut it. Picking up 50 or 60Hz noise is way too easy. In fact network cards and most RF receivers come with a bandgap filter for the mains frequency in order to make them work reliable in an urban area. Even cell phones have great difficulty to get rid of this noise in order to work properly. If you use your cell phone for audio recording, you might notice that it is bad in picking up the humm of a transformer. Since the phone can't tell if this is real noise picked up by the microphone you want to keep or "junk" received over the PCB wires or through the charger, the phone will supress this frequency. So there are two likely ways for the app: 1) Record audio with disabled filter (or tuned to the wrong frequency like EU instead of US) and detect the humming noise 2) use the FM tuner like a SDR (Software Defined Radio). You can use a cheap DVB-T USB receiver to receive almost anything. Most of the DVB-T devices contain a Realtech chipset which uses an 8-bit ADC to measure the signal strength for auto-tuning. This chip can be pushed to up to 8MHz sample frequency. A SDR software then can use this data to convert the strength signals to map the frequencies it contains (just like MP3 does). This allows to listen to any RF signal up to 4MHz. Since most of those DVB-T devices are equipped with a wide-band tuner, you can multiply the frequency range. A common international DVB-T device which contains the Realtec chip and a Phillips wideband tuner can let you listen to anything between a few kHz up to 2GHz. actually, the phone probes work poorly on live wires, because they are not discriminating enough. my non contact sensor triggers on 120V AC in about an inch. the phone probe picks it up at about 6 feet, and it can hear an electric motor a block away. however, my non contact sensors can very conveniently pick up transmission voltage about ten feet away, so in a compromised power line situation, I can use it as a backup warning device. |
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