H3FA
H3FA
140
External Resistor and Operate Time
When using an external resistor, refer to the characteristic diagrams shown below.
Use an external resistor rated at about 0.1 W/1 M
$
for H3FA(U) and -SA(U), and 0.1W/3 M
$
for H3FA-B(U) and -SB(U).
Pay attention to external noise and keep the lead length to less than 2 m. Since the characteristic diagrams represent standard data, the oper-
ate time factory-setting may not always be uniform from one product to another.
Should higher timer precision be required, use of a variable resistor is recommended for time adjustment.
Note that the operate time becomes slightly longer than the set time as the length of the leads increase.
Operat
e
ti
m
e
(%
)
Operat
e
ti
m
e
(%
)
External resistor (M
$
)
External resistor (M
$
)
H3FA-A(U)/-SA(U)
H3FA-B(U)/-SB(U)
When Prolonging Reset Time
The time unit has a shorter reset time than conventional timers so that it can be used in combination with solid-state circuit. To prolong the reset
time of the time unit while it is in operation to about 100 ms, connect a capacitor having the listed constant to the time unit as shown below.
Since the reset time after the set time is up varies depending on the load relay connected, select an appropriate capacitor having the desired
constant taking into consideration the load relay connected. For the pulse output types (H3FA-
j
U), since the reset time before the set time is up
varies depending on the load relay connected, select an appropriate capacitor having the desired constant taking into consideration the load
relay connected.
Rated voltage
Capacity of capacitor
12 VDC
10
&
F, 25 V
24 VDC
4.7
&
F, 50 V
5, 6 VDC
22
&
F, 16 V