Pulse counter 871

digitalelectronicprogrammable

8-decade presettable timer and counter 25-MHz positive or negative input count rate Crystal-controlled time base Auto recycle dwell time control The ORTEC Model 871 is a nonprinting timer and counter and may be used in any system as a counter and presettable timer, timer and presettable counter, or as two counters. Integrated and hybrid circuitry, combined with an 8-decade light-emitting diode (LED) display, give excellent operational reliability at a very economical cost. A 1-MHz crystal-controlled oscillator, which serves as the standard time base for the unit, provides substantially improved timing accuracy over timers using a line frequency time base. The 8-decade LED display is a highly legible count or time indicator, further enhanced by suppression of the leading zeros, which minimizes the possibility of errors in readout. An LED below the 8-digit display indicates if the reading is for the counter or the timer, and a push-button below the display allows the user to alternate reading the counter or the timer. LED digits are also used to indicate the presets in an M X 10N format. The display test is activated by pressing the front-panel Display Test switch, which illuminates all "8s," thereby providing a test for all segments of each display.