out a bandwidth limit of 20 This is because on oneripple handisthe CM element datawith sheet, however, reveals thatMHz. the measurement of output typically carried beyond 20MHz is not so significant because it can be easily filtered out with a small out with a bandwidth limit of 20 MHz. This is because on one hand the CM element TECH SERIES capacitor and onisthe other hand the measurement should not befiltered dependent on the type beyond 20MHz not so significant because it can be easily out with a small or manufacturer of the oscilloscope. An oscilloscope without the 20MHz BW capacitor and on the other hand the measurement shouldused not be dependent on the type imitation option will give higher An readings. or manufacturer of always the oscilloscope. oscilloscope used without the 20MHz BW
limitation option will always give higherPRACTICAL readings. TIP
Finally, the probe itself can be a source of error. Care must be taken that the cables to the Practical probe are as short as possible. Ideally, the tip of the probe touches to the + pin and the ground Tip Practical pin touches the ring. The use of the supplied earth clip must be absolutely avoided as the Finally, itself can be a source of error. Care must be taken that the cables to Tip the probe loop formed by the earth wire forms an aerial that picks up significant extraneous noise. the probe as short possible. Ideally, tipCare of themust probe to the pin and Finally, theare probe itselfas can be a source of the error. betouches taken that the +cables to the ground pin touches the ring. The use of the supplied earth clip must be absolutely the probe are as short as possible. Ideally, the tip of the probe touches to the + pin and avoided as pin the touches loop formed by the earth forms an aerial the ground the ring. The use wire of the supplied earththat clip picks must up be significant absolutely extraneous noise. avoided as the loop formed by the earth wire forms an aerial that picks up significant
extraneous noise.
Fig. way AC tosignals measure Fig. 3.2a:3.2a: WrongWrong way to measure
AC signals
Fig. 3.2a: Wrong way to measure AC signals
Fig. 3.2b: Correct way to measure AC signals
Fig. wayACto measure Fig. 3.2b.3.2b: Correct Correct way to measure signals
AC signals 87
87
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