Timeline for bi-directional flyback diode for relay spike protection
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Dec 4, 2015 at 17:42 | vote | accept | AHB | ||
| Dec 4, 2015 at 17:38 | comment | added | Andy aka | If capacitance reduced to 1uF, the overshoot would be 38 volts on top of 9 volts - still quite practical in many circumstances. More capacitance means less overshoot. You could of course use a resistor - the 12mA into a 1k resistor would be 12V and this isn't much to deal with but can you tolerate the resistor drawing 9mA when the power supply feeds the coil? | |
| Dec 4, 2015 at 17:29 | comment | added | AHB | you adjusted the coil resistance not to change the current through coil? lol. //// thanks. now, Is there any problem if the capacity is more? (or less?) | |
| Dec 4, 2015 at 17:26 | history | edited | Andy aka | CC BY-SA 3.0 |
added 125 characters in body
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| Dec 4, 2015 at 17:23 | comment | added | Andy aka | @BlueSky I misread 9V as 12V - i'll fix up my answer and address Spehro's point. | |
| Dec 4, 2015 at 17:16 | comment | added | Spehro 'speff' Pefhany | The problem with just using a capacitor is that it could kill the switch when the switch closes.. so better an R-C snubber. | |
| Dec 4, 2015 at 17:15 | comment | added | AHB | what is "the 12V" which is disconnected? | |
| Dec 4, 2015 at 17:09 | history | answered | Andy aka | CC BY-SA 3.0 |