As protection circuit I have used a 51ohm from the front panel input to the TICC input than two diodes one from TICC input to gnd , other from TICC input to +5V. A swichable 51ohm from front panel input to gnd allow to have 1M or 50 ohm as input impedance. The front panel leds are drived from 2N3904 transistors connected to: A14 for the channel A A15 for the channel B PPS for reference 10MHZ (close to the pic divider) PW1 for the TX data (a 2N3906 instead 04 is used as not inverting function) Luciano www.timeok.it
Da "time-nuts" [email protected] A "[email protected]" [email protected] Cc Data Thu, 30 Mar 2017 20:15:09 +0000 Oggetto [time-nuts] TAPR TICC boxed What did you do for input protection? I want to build an input system for the TICC that incorporates some input protection, switchable terminator, possibly settable threshold and edge selects, and a switchable PICDIV divider like the TADD-2 Mini. That would allow inputs of <1 .. 100 (or maybe up to 1000) PPS and 1/5/10/15 MHz inputs. The main problem I'm having is coming up with an input squarer circuit that is simple and cheap but can handle basically DC-15 MHz. Anybody got any ideas? _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
