Agilent 1956-07 free download

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HEWLETT-PACKARD JOURNAL TECHNICAL INFORMATION FROM THE -ftp- LABORATORIES Vol. 7 No. 11 -12 ^B^^^^^^^^^^H iLISHED BY THE HEWLETT-PACKARD COMPANY, 275 PAGE MILL ROAD, PALO ALTO, CALIFORNIA JULY-AUGUST, 1956 A 0-1.1 MC Frequency Counter with Time Interval Markers ANEW -hp- frequency counter has been cies, measure the period or 10-period average designed which incorporates a number of lower frequencies, and act as a secondary of new features and which also includes the frequency standard by making available ex previously-developed features that have al ternally an accurately-controlled 100 kc fre ways given -hp- counters their leading posi quency. tion in the field. The new counter measures The basic circuit arrangement of the new frequencies from 0 to 1.1 megacycles and counter is shown in Fig. 3. The frequency to time intervals from 3 mi be measured is passed through a gate circuit croseconds to 27.8 hours. which is opened by a precision time-base cir These ranges suit the in cuit for an accurately-controlled interval strument to much of the frequency-measur such as 1 second. A panel switch permits the ing work that goes on in a typical electronics operator to select in decade steps any of five laboratory as well as to almost any of the gate times from 1 millisecond to 10 seconds. mechanical applications where a counter is The cycles of the frequency to be measured useful such as in measuring rpm, velocity, that pass through the gate are then applied flow rates, etc. Besides measuring frequency to a series of six decade counting units which and time intervals, the instrument will also indicate in illuminated numerals the num count events, i.e., totalize, for as long as de ber of cycles that have occurred while the sired, form the ratio of two external frequen gate was open. The measured frequency can Fig. 2. Oscillogram showing how time in