© National Instruments Corporation 17 NI 6509 User Guide and Specifications

Figure 6. Limiting Flyback Voltages at the Inductive Load

Sinking and Sourcing Examples

The following sections provide examples of driving a relay less than

24 mA, driving a relay greater than 24 mA, and driving solid-state relays.

Driving a Relay <24 mA

Figures7 and 8 show examples of connecting the NI 6509 to a relay that

does not require more than 24 mA of current.

Figure 7. NI 6509 Sinking Connection Example, <24 mA

Figure 8. NI 6509 Sourcing Connection Example, <24 mA

P
X
.
Y
GND
Load
NI 6509 Flyback Diode for
Inductive Loads
P
X
.
Y
GND
NI 6509
Vcc
P
X
.
Y
GND
NI 6509