Hi Joe, I didn't see any replies to your question, so I thought I'd comment. I do not think the open collector driver on X2 will be damaged if it has 13.8 v on its collector while the SDR is powered off provided the SDR and the 13.8 v source share a common ground. There will be no base current into the X2 open collector transistor when the SDR is off which is the same condition as when the transistor not being energized. The 13.8 v should be applied to the collector through some current limiting load, so the current will be ok even if the transistor is turned on which is the normal turn on state.
Hope this helps...73 Tom W0IVJ Joe Barger wrote: >A quick question. Is it OK to have voltage (+13v) applied to the open >collector control signals on X2 when the SDR1000 is powered off? Or will that >fry the open collector output since it's not biased correctly? Should I use >the +5v on X2 pin 14 to control a relay that enables the +13v so no voltage is >applied to the X2 pins if the SDR1000 is off? > >Thanks > >joe N6KK >-------------- next part -------------- >An HTML attachment was scrubbed... >URL: >/pipermail/flexradio_flex-radio.biz/attachments/20060727/da1a093d/attachment.html > >_______________________________________________ >FlexRadio mailing list >FlexRadio@flex-radio.biz >http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz >Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ >FlexRadio Homepage: http://www.flex-radio.com > > > > _______________________________________________ FlexRadio mailing list FlexRadio@flex-radio.biz http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archive Link: http://www.mail-archive.com/flexradio%40flex-radio.biz/ FlexRadio Homepage: http://www.flex-radio.com
