©
National Instruments Corp.
7
FP-RLY-420
Diode Circuit
CR Circuits
Varistor Circuit
Diagram
Notes
Use in DC applications only.
Compared to RC type, circuit delays release
time (2 to 5 times values stated in catalog).
For larger voltages, use diode with reverse
breakdown 10 times circuit voltage and
forward load circuit.
For smaller voltages, use reverse breakdown
voltage of 2 to 3 times power supply voltage.
Diagram
Notes
Circuit A is suitable for AC or DC
applications, but if used with AC
voltage, impedance of the load
should be smaller than the CR
circuit’s. Do not utilize for timer
loads, as leakage current can cause
faulty operations.
Circuit B is suitable for AC or DC.
If the load is a relay or solenoid,
release times lengthen. Effective
when connected to both contacts,
power supply voltage across the
load is 100 to 200 V.
Diagram
Notes
Effective for AC and DC
applications.
Circuit slightly delays release time.
Effective when connected to both
contacts, power supply voltage
across the load is 100 to 200 V.
Load
Load
Load
Load
