Timeline for What causes this resistor to fail - open circuit and no visible damage?
Current License: CC BY-SA 3.0
7 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Sep 4, 2017 at 10:32 | comment | added | marcelm | Adding to this answer: mains power can sometimes exhibit nasty transient pulses, e.g. from switching off a heavy inductive load (just a vacuum cleaner may do the trick). These might exceed 500V, violating the overload specs for the resistor as well. | |
| May 17, 2014 at 3:52 | comment | added | Brian Wang | @markrages Thanks for the suggestion. That is one possible workaround. It is just that I am trying to figure out the exact cause of death of the resistor from a theoretical stand point. That would make me sleep better at night. :-) | |
| May 17, 2014 at 3:49 | comment | added | Brian Wang | @Barry Should we look at the max overload voltage instead of the max working voltage for the peak voltage? The max overload voltage is 500V, which is well above the peak voltage seen here. | |
| May 17, 2014 at 3:45 | comment | added | markrages | The old trick is to use several resistors in series, instead of single small high-impedance resistors. 1/4W resistors are not that expensive. Also, I don't think 1% tolerance is necessary in this application. | |
| May 17, 2014 at 3:39 | comment | added | Barry | I would interpret the maximum working voltage as the maximum voltage allowed across the resistor independent of time. Thus AC or DC is irrelevant especially since we are talking about peak voltage. RMS is an average so that a waveform could have a low RMS value but a very high peak value (for example, a signal composed of narrow pulses). The RMS voltage is more appropriate for checking the power being dissipated in the resistor. The peak voltage is appropriate for checking against a maximum voltage specification. | |
| May 17, 2014 at 3:14 | comment | added | Brian Wang | Does it matter if this peak voltage (> 300V) is a DC or AC signal? I thought the max working voltage is specified as Vrms/Vdc. | |
| May 17, 2014 at 3:08 | history | answered | Barry | CC BY-SA 3.0 |