Once the detector has been tested as far as it can be on the workbench and the dial has been calibrated, it’s time to venture out at dusk. In this waythe total system gain can vary anywhere from 400 to 40,000. For a schematic drawing of the circuit, click HERE. While some bats do make audible clicks, most produce inaudible clicks that are between 20kHz and 200kHz. Intelligent Bat Detector: Bats emit echo location calls at high frequencies to enable them to 'see' in the dark and we humans need to be able to monitor the species to help prevent destruction of their environment during our ever increasing exploitation of the planet. The circuit is built with BC550 transistors at the front end, a TL071 OpAmp oscillator, a SA602 Mixer and a LM386 output amp. The bat calls are picked up by an ultrasonic microphone and compared against the frequency you set.
The simple bat detector uses frequency division to lower the bat’s chirping to a frequency we can hear. Besure to keep the positive side of the capacitor towards pin #1 onthe LM386. Bats come out at night and can be difficult to spot—but with this bat detector, you will be able to track them down! Heterodyne bat detectors are tuneable, you select the frequency range to listen to, and bat calls near that frequency are converted to sounds which you can hear.
Another Bat Detector, similar in appearance but a bit larger and of my own making is shown at right. After he retired, he decided to act on this fascination and built a simple bat detector. A resistor / capacitor combination can also be addedbetween pins 1 and 8 of IC-2 to increase it's gain. After a little more experimentation, I decided to design a board for an enhanced version of the Simple Bat Detector. Using the Bat Detector. Start by setting the frequency to about 30 kHz. You should hear a … I took the opportunity to add components that were left out of the original design for the sake of providing easy prototype style assembly. Hearing your first bat is a very satisfying experience. If you're experienced in electronics assembly,you can usually build a Simple Bat Detectorin a singleevening. Using a Printed Circuit Board makes it easy !!!