Paul... This is not exactly what you are describing, but it fails open. https://hifimediy.com/usb-isolator
I've used one at a digipeater site and it took a static hit think - nearby strike - it protected the TNC and PC. It was open on every line. I have used them for ground loops with sound cards. 5000v isolation (advertised), but it did fail open! Hank K4HYJ -----Original Message----- From: [email protected] <[email protected]> On Behalf Of Paul Christensen Sent: Friday, June 28, 2019 12:37 PM To: [email protected] Subject: [Elecraft] KIO3B USB Surge Suppressor Looking for input from anyone who has successfully installed a surge-suppression device on a USB port. I am in the process of repairing a KIO3B board after a recent thunderstorm. The KIO3B uses an ST Microelectronics USBLC6-2 ESD protection device at the front end of the K3's USB connector. The protection device is a SOT chip that contains five low-capacitance diodes to clamp voltage to acceptable limits. In this case, the diodes have shorted, causing the USB connector to show a dead short to the PC's USB port, which causes an overload to the PC's USB power bus. This has caused all USB ports to disappear in Windows Device Manager. The short goes on until I can get to the remote site, sometimes days or even weeks later. Ideally, I would like to find a USB protection device that is designed to fail open - open as in an open circuit into the USB driver that follows. That way, I can still find a problem if Windows Device Manager doesn't show a USB connection while not risking the destruction of the PC's USB power bus. Paul, W9AC ______________________________________________________________ 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 Message delivered to [email protected] ______________________________________________________________ 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 Message delivered to [email protected]
