Time Expansion Bat Detector Circuit

Te detectors are real time devices in that they can be monitored at the time of recording but there is an inevitable delay while the high speed sampled extract is.

Time expansion bat detector circuit.

A 5 ms bat call at 40 khz would sound like a 50 ms call at 4 khz. Typically the sampling rate ratios can be varied from 1 10 to 1 32. The advantage of this system is that all frequency information is retained for later analysis. Bat sounds are heard at 1 10th the frequency and 10 times the duration so no frequency information is lost as is the case with heterodyning or frequency division.

A bat detector is an electronic listening device that will allow us to hear the bat chirps and buzzes. Time expansion detectors work by storing the call in their internal memory and then replaying it back 10 x slower thus lowering the frequency. Time expansion te detectors work by digitising the bat calls at a high sampling rate and replaying them at a lower sampling rate immediately afterwards. Chris eve s bat detector circuit view experiment.

Heterodyne detectors are great for beginners but professional bat workers will also turn to the more technologically advanced models which allow extensive recording and. They work by digitally recording a brief snatch of bat sound usually about one second and replaying it at a slower rate usually ten times slower. They detect all frequencies across the frequency range within which bats are likely to be calling. The output is audible on a loudspeaker or headphones.

Time expansion te detectors are broadband detectors i e. Hand held or passive and type of technology heterodyne fixed frequency time expansion or full spectrum. A time expansion detector needs some kind of memory to store the bat call. Bat detector choices are influenced by factors such as your experience the mode of operation that you want e g.

Frequency divider heterodyne time expansion dsp digital signal processor.