In this paper is presented a device that can realize the multiplexing of three logical signals with the purpose of simultaneous display on the oscilloscope screen. The device delays in time and amplitude the three signals as well as it synclironizes the oscilloscope time base with the tact signal. Being made with cheep and reliable elements, the device makes it possible for a single channel oscilloscope to be used for diverse application in the analysis of the way logical circuit work.
