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> Cap analyzer 88A-ii unique cap in-line capacitor tester
Cap analyzer 88A-ii unique cap in-line capacitor tester
CHECK ANY ELECTROLYTIC CAPACITOR, "IN-CIRCUIT," WITH 100% ACCURACY IN THREE SECONDS! YES, THREE SECONDS!
SAVES TREMENDOUS AMOUNT OF WASTED TIME LOOKING FOR BAD CAPACITORS!
As a cap ages, it can cause problems in the particular circuit it is in. In a CRT vertical section, it can cause underscan or overscan problems. In audio or mpx circuits it can cause distortion or low audio. In the syscon supply it can cause intermittent functions and mpu confusion. In the video circuits it can cause a fully scrambled picture. In VCR or camcorder servo circuits, it can cause unstable speeds. Most VCRs and big screens also use surface mounted electrolytics in the sound MPX decoder module and video PIP and convergence circuits. High-end audio, video and computer products use tantalum capacitors that can become leaky by as much as 500 ohms. Computer motherboards are another user of electrolytics that must have super-low ESR, or else strange problems and freezing can occur.
The trick to locating bad capacitors in circuit is not just to measure capacity, but instead, to measure Equivalent Series Resistance (ESR) and DC Resistance (DCR) in relation to capacitance. A perfect capacitor will measure as an open circuit at DC, and will show less AC resistance as the frequency across it increases. Most cheap cap meters utilize this fact by measuring a cap's impedance at a fixed frequency such as 1 KHz and translating the reading to capacity. In reality, checking a cap at 1KHz is pointless because in TVs, video monitors, and PWM power supplies, frequencies of 100 KHz and higher are used. The CapAnalyzer 88 was the first device that would measure both DCR and ESR automatically.
