Game Circuit Sounds from the IC IT82207 Crossed from: Inside Circuits | Clicks: 18665 | Votes: 2 | Comments: 0 | Rating: 7.5 | Rank: 2 This circuit is able to take you to the world of the Wild West. For this it uses the integrated 18-pin IT82207 (IC1) of Holtek, which literally takes care of everything. You have to do is add a few accessories, including a loudspeaker and six selector switches. .. Ultrasonic Bat reciever Crossed from: Inside Circuits | Clicks: 224 | Votes: 0 | Comments: 0 | Rating: 0 | Rank: 0 ??? won't be disappointed with the performance of this sensitive ultrasonic receiver. It can let you listen to bugs, bats, engines, and virtually any other source of ultrasonic sounds. The circuit uses a piezo tweeter as an ultrasonic microphone, amplifier stages Ql, Q2, and an LO using a 567 IC. Q3 is a mixer that heterodynes the ultrasonic sounds down to the audible range. U2 is an amplifier that will drive a pair of headphone