To answer, I hope definitively, the question "is a 1N4007 power diode too slow to be used as a relay coil snubber," I've updated my December 2007 diode turn-on time measurements with data taken this morning showing the effectiveness of (a) no snubber; (b) 1N4148 snubber and (c) 1N4007 snubber with a typical small relay switched by a 2N7000 MOSFET transistor. I've also looked at the how much the relay release time lengthens when a snubber is added. (Of course, the specifics are dependent upon the particular relay but the concepts are similar.)
The details are at http://www.cliftonlaboratories.com/diode_turn-on_time.htm The "Cliff's Notes" version is that the turn-on (note I said turn-on, not turn-off) time of a 1N4007 diode is sufficiently fast to be a very effective relay snubber. The data also shows that a diode or MOV or other technique should be used to control inductive field decay voltages. Jack K8ZOA www.cliftonlaboratories.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
