Agilent 1959-05 free download

File name 1959-05.pdf

HEWLETT-PACKARD V " f T E C H N I C A L JOURNAL I N F O R M A T I O N F R O M T H E - h p - L A B O R A T O R I E S )l. 10, No. 9- 10 PUBLISHED BY THE HEWLETT-PACKARD COMPANY, 275 PAGE MILL ROAD, PALO ALTO, CALIFORNIA MAY -JUNE, 1959 A Clip -On Oscilloscope Probe for Measuring and Viewing Current Waveforms A though current is a fundamental quantity tion the general problem of measuring alter in electronic circuitry and accurate knowl nating currents is made much more convenient edge of it is valuable, it is a quantity that has by a new oscilloscope probe which permits always been rather inconvenient to measure both viewing and measuring alternating cur and in at least one important case quite diffi rents merely by clipping the probe around the cult. This is the case of alternating currents in current conductor. The probe operates with the circuits elevated from ground. Here, to use a -hp- Model 150A Oscilloscope and a new plug- current meter involves at best the trouble of in amplifier to measure and display currents opening the circuit, while the meter, when con over an amplitude range from 1 milliampere nected, will usually not indicate such often- to 15 amperes peak-to-peak and over a fre needed information as the current's peak value. quency range from below 500 cps to 8 mega At the same time to measure the current wave cycles. In the case of sinusoidal currents, wave form in such circuits with an oscilloscope has forms down to about 50 cps can be displayed. required the combination of a suitable circuit Electrically, the probe consists of a wide- resistance to connect across and an oscilloscope range current transformer with a split core with a differential input of adequate range, a which is mechanically opened and closed by combination