Data Sheet

-118-
293. High Impedance Input
Connect points C and D with a 4-wire (4) in project #292. Hold the
magnet (7) near the reed switch (83) and you will hear gun shots and
the motor (95) will spin at the same time.
Note that this circuit places a 100W resistor between the T2 input
and ground when you place the 4-wire (4) across points C and D. This
is because T2 is a high impedance input. Impedance is a measure
of the opposition of a circuit or input to current ow. Thus, a high
input impedance means that in normal operation only a small amount
of current will ow through the circuit or input, but which will be enough
to activate the input.
294. Active High Input – T1
Connect points A and B with a 4-wire (4) in project #292. Hold the
magnet (7) near the reed switch (83) and you will hear a re siren and
the motor (95) will spin at the same time.
Connecting points A and B connects the T1 input to 4.5V. This
demonstrates that T1 is an active high input because the re siren
sound function is activated when the T1 input is pulled to a high voltage.
295. Active Low Input – I/O2
Connect points E and F with a 4-wire (4) in project #292. Hold the
magnet (7) near the reed switch (83) and the sounds of space battle
will turn on and the motor (95) will spin at the same time.
Connecting points E and F connects the I/O2 input to ground (0V). This
demonstrates that I/O2 is an active low input because the space war
sound function is activated when the I/O2 input is pulled to a ground.
296. Active Low Input – I/O1
Connect points G and H with a 4-wire (4) in project #292. Hold the
magnet (7) near the reed switch (83) and you will hear music and the
motor (95) will spin at the same time.
Connecting points G and H connects the I/O1 input to ground (0V). This
demonstrates that I/O1 is an active low input because the music sound
function is activated when the I/O1 input is pulled to a ground.
[ 293 - 296 ]