using diode switching a single pair of wires controls two circuits that normally here with lamps , the same idea can be used for telephone circuits. when polarity-reversing switch S 1 is set so the positive battery terminal feeds the top wire, the D 1/L 1 circuit is operative and only lamp L 1 lights up. lamp L 2 remains off because diode D2 blocks the flow of DC to the lamp.
when battery polarity is reversed. so the top wire is negative. only D2 conducts, illuminating 12. D1 blocks the current flow and L1 is off.if a carbon mike is connected in series with the battery and the lamps are replaced with headphones, switch S1 determines which of two headphones receives the transmitted signal.
when battery polarity is reversed. so the top wire is negative. only D2 conducts, illuminating 12. D1 blocks the current flow and L1 is off.if a carbon mike is connected in series with the battery and the lamps are replaced with headphones, switch S1 determines which of two headphones receives the transmitted signal.
No comments:
Post a Comment