Til min defekte Samsung SyncMaster 204B monitor anbefales det at udskifte med nedenstående kondensatorer:
820uF/25V Capacitors (C110, C111)
Da der er ventetid i DK på anskaffelse, har jeg i stedet hos Brinck bestilt nedenstående kondensatorer:
1000uF / 25V Lodret elektrolyt (105°C)
Dog er jeg efterfølgende blevet lidt i tvivl om det var en særlig god ide? Eller sagt på en anden måde - jeg ved ikke særligt meget om kondensatorer, men en gang lodning kan jeg nok klare.
Og så finder jeg det ublu for så beskeden en varemængde at betale ca.19 Euro i forsendelsesomkostninger fra Tyskland :-(
Jeg plejer tit at skifte 1000u/16v og 25v ud med 470u/35v. Det er bare fordi jeg har en røvfuld af dem, og det er gode holdbare typer. Og det virker uden problemer. Når man tænker på hvor dårlige lytter man ofte ser mens apparatet stadig virker, så kan det kun blive bedre, næsten ligegyldigt hvad man smider i. 820u er ret usædvanligt, og der er nærmest aldrig nogen speciel grund til den værdi er valgt. Så bare smid noget andet i, helst i et større hus hvis det kan være der, så holder de længere fordi der er mere væske at fordampe af. Og hvis printet er lagt ud til nogle ekstra parallelt som ikke er monteret, så kan man også forlænge levetiden ved at montere dem.
Selvfølgelig altid nogen der kan tåle den samme spænding eller mere, end de oprindelige.
The electrolytic cap ESR problem, and this meter...by Bob Parker the designer of the ESR Meter Kit (Mark 1):
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Citat: "... The real fault with many of these electros was not so much that their capacitance had dropped (as many people assume), but their Equivalent Series Resistance (ESR) had risen to a high value, seriously degrading their effectiveness as filtering, bypassing and coupling components. ..."
Hints for techs using Bob Parker's ESR meter(kit)...:
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Citat: "...Bob Parker's excellent ESR meter (January 1996) will also test all types of cells and batteries..."
Bob Parker's ESR Meter Page:
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"... Display: 2x high efficiency Super-Red GaAlAs Kingbright SC56-11SWRA
7 segment LED displays...."
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Andre ESR-metre:
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An Equivalent Series Resistance Meter (uden mikrocontroller):
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Citat: "...With my ESR meter I quickly found five electrolytic capacitors which had degraded a lot...one had 6 Ohm, one 7 Ohm, and the other two had such high ESR that the meter wouldn't even deflect!..."
Building an ESR meter for Testing Electrolytic Capacitors (uden microcontroller):
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ESR & Low Ohms Meter Page (K-7204 original) K-7214 (MK2):
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The "Genie" ESR capacitor tester & Low Ohms Meter
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Capacitor Testing, Safe Discharging and Other Related Information Version 2.42 (22-Nov-05):
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Citat: "... Before I bought my ESR meter I too wondered--what exactly did it measure? Nevertheless, having heard so much about the meter, I went ahead and bought one. It works, and that's the real bottom line. ... The objective of the ESR meter is to identify capacitors that have gone bad. This is more the case with electrolytics where the dielectric compound tends to dry up. ..."
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Citat: "... Table of approximate worst-case (highest) ESR values for new electrolytic capacitors at 20 degrees C (68'F). ESR generally decreases with increasing temperature. ...
10,000uF...0.12 [Ohm for 10V] ...0.08 [Ohm for 16V] ...0.06 [Ohm for 25V] ...0.04 [Ohm for 35V] ...xxx [Ohm for 63V] ...xxx [Ohm for 100V] ...xxx [Ohm for 250V] ... Notes: These figures are a guide only! Some electrolytics (especially high temperature types) can give higher readings and still be OK. Others can read significantly lower and be OK. In general, be wary of a capacitor with an ESR reading more than double the figures shown here. If you get a reading less than half, check the capacitor with an ohm meter... it might be shorted.
Det var da ligegodt pokkers med dig. Nu har jeg jo netop ikke flere gode undskyldninger. Hvad pokker, vi går tiden i møde, der er som skabt til at sidde med loddekolben og bande over hvor små de s****s SMD'ere er.
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