Tone dial encoder

Built around an LM380, this amplifier includes tone controls and electronic soft switching. The soft switching circuitry ensures power is balanced. The LM380 is a power audio amplifier capable of delivering up to 14 watts of output power. It is...

This encoder can generate up to 19,683 codes from 9 address lines by detecting 1, 0, or an open circuit. To initiate the transmit sequence, pin 14 should be pulsed low. The encoder will output a data stream on...

This circuit is designed for children's entertainment and is suitable for installation on bicycles, battery-powered cars, motorcycles, as well as models and other games. When switch SW1 is positioned as indicated in the circuit diagram, it generates the typical...

The two-tone electronic doorbell circuit consists of an input trigger circuit and an audio output circuit. The input trigger circuit includes a doorbell button (S), a transistor (V1), resistors (R1-R3), a capacitor (C1), and a dual D flip-flop integrated...

This circuit allows for monitoring a local VHF FM repeater for calls from friends without the need to listen to the background chatter or noise from the repeater. Its operation mimics that of Motorola paging units, where a special...

This circuit illustrates the TP5700 interfacing directly with a low-voltage DTMF generator. VREGt provides the required minimum bias of 2 V to enable the TP5380 to detect key closures and pull its mute output high. Subsequently, VREGt switches to...