Time Expansion Bat Detector Circuit

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.

Time expansion bat detector circuit.

The output is audible on a loudspeaker or headphones. Chris eve s bat detector circuit view experiment. A time expansion detector needs some kind of memory to store the bat call. A bat detector is an electronic listening device that will allow us to hear the bat chirps and buzzes.

Time expansion te detectors work by digitising the bat calls at a high sampling rate using an analog to digital converter and storing the digitised signal in an on board memory. 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. The advantage of this system is that all frequency information is retained for later analysis. They detect all frequencies across the frequency range within which bats are likely to be calling.

Hand held or passive and type of technology heterodyne fixed frequency time expansion or full spectrum. Time expansion detectors work by storing the call in their internal memory and then replaying it back 10 x slower thus lowering the frequency. 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.

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. 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. Time expansion bat detectors. There are several types of bat detectors being used by bat listeners.

A 5 ms bat call at 40 khz would sound like a 50 ms call at 4 khz.