Abstract: A synchronized sounding/flashing circuit includes a sound synthesizer stored with sound data and emitting sound signal upon being supplied with power, a digital-to-analog converter connected to the sound synthesizer for converting the sound signal to an analog signal for driving an external speaker, a sound level/density detector connected to the sound synthesizer for generating a detected signal in response to the sound signal therefrom, a frequency generator being connected to the sound synthesizer and triggered thereby when the sound synthesizer outputs the sound signal and outputting a signal having a frequency according to the detected signal, a flasher being connected to the sound synthesizer and triggered thereby when the sound synthesizer outputs the sound signal, and being connected to the frequency generator for sequentially and alternately outputting a pulse from a plurality of output terminals thereof with a frequency proportional to the frequency of the signal outputted from the frequency generat

Abstract: A digital/analog sound synthesizing circuit comprises an RC oscillator outputting a system basic frequency, a timing generator converting the basic frequency into timing signals, a sound synthesizer producing sound numerical code data, and a digital/analog converter outputting an analog signal to drive a speaker. A voltage stabilizing circuit controls the RC oscillator and the digital/analog converter to eliminate sound frequency and volume instability.

Abstract: A centrally controlled voice synthesizer includes a memory which is preprogrammed with voice data, melody data, address data, and control data, an input processor for receiving an external signal and outputting a triggering signal, a clock generator for generating clock signals; a control logic unit receiving the clock signal from the clock generator, being triggered by the triggering signal from the input processor thus fetching the voice data, the melody data, the address data, and the control data from the memory, a decoder decodes the data fetched from the memory via the logic control unit and generates a control signal, a rhythm generator for outputting a rhythm signal to the logic control unit upon receiving the clock signal from the clock generator and the control signal from the decoder, a digital-to-analog converter connected to the memory and converts digital voice data from the memory to analog voice signal, a transistor connected to the digital-to-analog converter for amplifying the analog voice s

Abstract: An improved digital/analog converter circuit of the analog multiplying type for providing an adjustment for a DC voltage offset. The digital/analog converter circuit generally comprises a code converter, an analog multiplying current source and a bridge output circuit. The code converter converts the values of the tone data into 2's complement numbers. The numbers are then sent into an analog multiplying current source where positive and negative signals are produced to control the current path of a bridge-type output.