Heterodyne Bat Detector Schematic

The by far most popular method for bat detectors appears to be the heterodyne down converting if you judge by the number of commercial and home built circuits frequency compression or time lapse this is the most advanced technology based on digital signal processing of the sampled bat sounds but it also requires the most advanced electronics.

Heterodyne bat detector schematic.

There are other types of detectors which record bat calls so that they can be analysed afterward but these are more commonly referred to by their particular function. A device that lets you listen to and record the sounds emitted by bats. Bat detector choices are influenced by factors such as your experience the mode of operation that you want e g. Build a semiprofessional bat detector with the teensy 3 6 microcontroller teensy audio board for less than 100 i developed this bat detector in the hope that it will promote the study of bat calls by everyone who is interested in the natural history and bioacoustics of bats and or interested in the technical details of how the detection.

This project is about building a so called bat detector i e. The current consumption is very low at only 8 ma which allows it to operate for about 100 hours with a set of rechargeable batteries. Heterodyne detectors are great for beginners but professional bat workers will also turn to the more technologically advanced models which allow extensive recording and. Heterodyne detectors are the most commonly used and most self build detectors are of this type.

A bat detector is a device used to detect the presence of bats by converting their echolocation ultrasound signals as they are emitted by the bats to audible frequencies usually about 120 hz to 15 khz. Hand held or passive and type of technology heterodyne fixed frequency time expansion or full spectrum. A heterodyne function is often also built into the other types of detector. It has been optimised for the use of an electret microphone.

This was first presented by popular electronics magazine as an ultrasound detector in 1994. Schematic of a heterodyne bat detector. Click image for a larger jpeg view. This means that realistic sounding calls are heard but bear in mind that they have been frequency shifted and are representative artifacts of the original sounds.

From popular electronics 1994 the circuit shown here is for a heterodyne bat detector. This is a schematic for a straightforward direct conversion heterodyne detector having a tuning range of about 10 khz to 120 khz. This bat detector is a heterodyne design. Construction is straight forward and can be laid out very much as the schematic shows.

These sounds lie in a frequency range above the human audible range and thus can t be heard directly. As you probably know bats emit ultrasonic sounds for the purpose of echolocation.