| 摘要 |
<p>A time base circuit for a waveform sampling system produces a strobe signal for initiating waveform sampling an adjustable strobe delay time following detection of a triggering event in a waveform. The time base circuit includes a strobe control circuit for producing the strobe signal and a strobe sense signal in response to a strobe drive signal, a strobe drive circuit for generating the strove drive signal, an adjustable time after a trigger signal, and a trigger generator for producing the trigger signal in selective response to either the triggering event in the waveform or the strobe sense signal. The strobe signal delay time is calibrated by setting the trigger generator to produce the trigger signal in response to the strobe sense signal thereby causing the strobe drive circuit to generate the strobe drive signal periodically. A period timer measures the period between successive strobe drive signals and a microprocessor adjusts the delay time of the strobe drive circuit so that the period between strobe drive signals is equal a predetermined delay time.</p> |
