Title
LRP2000 Long Range Passive Reader/Writer
21
Figure 3-15. Sourcing Output 'Contact'
Figure 3.15 shows a relay connected as a current sourcing "Contact."
The relay is grounded and the +OUT terminal goes to the positive
supply. The diode across the relay coil is essential to protect the
output circuit and reduce noise along the wiring. It should be
connected at the relay to minimize the length of wiring that could
radiate noise. A 1N4001 or similar diode may be used.
Figure 3-16. Sinking Output 'Contact'
Figure 3.16 shows a "Contact" sinking current from a relay, the -OUT
terminal is grounded and the relay goes to the positive supply. This
configuration must also have a diode across the relay coil to protect
the circuit and reduce noise.
