DS

This circuit takes two separate line-level stereo (L & R) signals and combines them into one stereo (L & R) output, thus avoiding the need to switch between two pairs of input signals. In the author’s application, it is used to feed the stereo audio from a TV receiver and a DVD player into an external amplifier. The need for the circuit arose because of a design peculiarity in the TV receiver. The TV has four A/V inputs and one A/V output. AV1-AV3 accept composite or S-video plus stereo audio inputs and these feed into the TV’s A/V output. AV4 accepts Component video (Y/Pb/Pr) plus stereo audio but unlike AV1-AV3, its audio (and video) signals are not fed to the TV A/V output. The Y/Pb/Pr input was chosen for use with the DVD player because of its superior video quality, while the audio was to be fed to an external amplifier for improved reproduction. Circuit diagram: Dual Input-Combining Stereo Line Amplifier Circuit Diagram However, manual switching was inconvenient, henc...

Dual Operational Amplifiers AN4558 Datasheet for AN4558: Download

Dual Trace CRO Block diagram of dual trace CRO is shown in the fig. there are two separate vertical input channels A and B. These use two separate attenuators and preamplifiers stages. Therefore the amplitude of each input as viewed on the oscilloscope can be individually controlled. After pre-amplification the two channels meet at an electronic switch. This has the ability to pass one channel at time into the vertical amplifier, via the delay line. Pic 1 The dual trace oscilloscope is basically operated in alternate and chop modes. The operating modes are selected form the instrument front panel. In alternate mode the electronic switch alternates between channels A and B, letting each through one cycles of the horizontal sweep display is balanced during the fly back and hold off periods. Provided the sweep speed is much greater than the delay time of the CRT phosphor, the screen will show a stable display of both the waveforms at channel A and B. In chopped mode the electronic switch ...