| Electronics > Projects, Designs, and Technical Stuff |
| Normal electrolytic capacitor in place of low and super low ESR electrolytic cap |
| << < (4/6) > >> |
| soldar:
--- Quote from: The Electrician on December 25, 2018, 10:22:56 pm --- ESR of aluminum electrolytics does not increase with increasing temperature--it decreases. --- End quote --- Well, I might be wrong although I think there may be two different things to consider here. It may be that as long as the cap is working at a safe temperature the ESR does indeed decrease with temperature. That makes sense to me. What I understand is that if excessive current for a given ESR takes the cap to working at excessive temperature for which it is not rated or designed then the electrolite is damaged or dries up and the ESR increases as a result which leads to a runaway process. The cap is permanently damaged. I believe this, which is what I have been lead to believe, is compatible with ESR decreasing over the acceptable working range of temperatures. |
| The Electrician:
--- Quote from: soldar on December 25, 2018, 11:19:08 pm --- --- Quote from: The Electrician on December 25, 2018, 10:22:56 pm --- ESR of aluminum electrolytics does not increase with increasing temperature--it decreases. --- End quote --- Well, I might be wrong although I think there may be two different things to consider here. It may be that as long as the cap is working at a safe temperature the ESR does indeed decrease with temperature. That makes sense to me. What I understand is that if excessive current for a given ESR takes the cap to working at excessive temperature for which it is not rated or designed then the electrolite is damaged or dries up and the ESR increases as a result which leads to a runaway process. The cap is permanently damaged. I believe this, which is what I have been lead to believe, is compatible with ESR decreasing over the acceptable working range of temperatures. --- End quote --- You could have avoided confusing your readers by specifying with respect to which operating regime you were commenting. |
| soldar:
--- Quote from: The Electrician on December 26, 2018, 12:11:23 am --- You could have avoided confusing your readers by specifying with respect to which operating regime you were commenting. --- End quote --- I do not see how any confusion can arise because what I was referring to is what is applicable to the case in hand. The OP will not benefit by using high ESR caps in place of the required low ESR caps. On the contrary. |
| BravoV:
--- Quote from: The Electrician on December 25, 2018, 10:22:56 pm ---ESR of aluminum electrolytics does not increase with increasing temperature--it decreases. --- End quote --- Not doubting about this, but, in practice & reality, it will be case by case basis, as I really wonder if the advantage of decreasing ESR can cope with the disadvantage of increasing ambient or surrounding temperature, if its placed near to heat source, like at PSU when the power usage increase, these heat sources like the semiconductors near to the cap tend to heat up significantly. As we aware, its the temperature that have significant effect on the cap's life, exponentially if I'm not mistaken. An example, the black cap that is near the heat sink, basically its constantly being toasted all the time if the air flow is bad, which is common in a cramped & packed PSU. |
| T3sl4co1l:
Note that ESR does not decrease much above room temperature. The admonition is mainly not to freeze the poor buggers. It is also an immediate change. Over a long time scale, high enough temperatures will dry it out faster, leading to increasing ESR even at room temperature. Tim |
| Navigation |
| Message Index |
| Next page |
| Previous page |