I think this is a good example of the practicality, and the style (BOOM!) of The Art of Electronics. This shows very nicely how failing to put a diode across a relay coil can get you into a lot of trouble. Boom, indeed.
Re: Fair Radio and Dayton Hamfest Photos May 2024
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Thanks—excellent pictures. I see many items that probably would have
followed me home, for better or worse.
#4828 and #4829: Nice old homebrew, with turns...
10 hours ago
Could never figure out why not build the diode into the relay during manufacture?
ReplyDeleteThere are some selected Omron and others that do have the built-in or "catch" diode.
DeleteSee:
https://www.ia.omron.com/support/faq/answer/36/faq03676/
But, true, the vast majority of DC relays do not.
For DC relays, having it built-in could help reduce EMI during the switch transient, by have a slightly smaller current loop or "antenna" if done properly.
73!