Have a look at the "cas inverter" schematic below. http://www.repeater-builder.com/nhrc/nhrc-5-cas-iinverter.pdf
instead of running the inverted signal into the controller, run it to your led. Chris Kb0wlf > -----Original Message----- > From: [email protected] [mailto:Repeater- > [email protected]] On Behalf Of tait700 > Sent: Friday, September 25, 2009 6:34 AM > To: [email protected] > Subject: [Repeater-Builder] Busy Signal (COS) inverter Circuit. > > Hello, > Was wondering if someone knowledgeable would be able to advise me on > the best way to proceed with this, > I need to extract a signal to power a normal LED that indicates when > the Mute has opened on a Receiver. > The Receiver has a "Busy" line coming from the Micro that supplies 5V > DC when the mute is closed ( Quiet ) and goes to OV when the Audio is > open ( Audible ) > I don't have any further info on the current available from the micro > and am a little dubious about running a small SPDT relay off this > signal. > I searched the RB site and found the article concerning the "maxtrac > cor buffer" which uses a Transistor to invert the logic but am not sure > how to apply this to a LED ( 20ma ) and whether the resistor on the > Base input would be the right value. > If i could do this without risking the health of the micro ( which > controls everything on the Board ) i would be very happy. > > Any info would be most appreciated, > > Regards, > > > > ------------------------------------ > > > > Yahoo! Groups Links > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.409 / Virus Database: 270.13.112/2392 - Release Date: > 09/24/09 18:00:00
