One point that I stumbled over is that adding a simple snubbing diode across a relay coil increases the relay hold time. The current flow through the diode when the supply voltage is removed goes through the relay coil, countering the spring force that is returning the relay to the "normal" state.
In a hot switching application, you may need the full spring force to pull the contacts apart quickly, or tack welds are created. If hold time or relay contact life reduction due to slow drop out while switching current are a factor, a slightly more complex snubber consisting of a zener diode in series with the diode might be appropriate. The zener voltage value is derived from the protection needs of the switching device. See http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3264.pdf and http://relays.tycoelectronics.com/appnotes/app_pdfs/13c3311.pdf for the details. Dick, K6KR ______________________________________________________________ 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
