TOS8870A
OPERATION PROCEDURE
25
■
Use examples of contact signal
To drive a DC buzzer with an ACW/FAIL or IR/FAIL alarms.
Fig.3-11
To drive a lamp with the TEST ON signal.
Fig.3-12
To obtain an "L" level digital signal with the contact signal.
Fig.3-13
In the Fig.3-13 illustration, an "L" level signal is obtained at point "a" when the contact output sig-
nal is on. However, since the signal obtained at point "a" include chattering, an appropriate chatter-
ing suppression provision should be incorporated depending on the nature of the circuit to be driven
by this signal. The minimum rating of the load applicable to the contact is 5 V, 10 mA or higher. Set
V
+
and R so that a load with higher rating is applicable. Noise measures are also required in some
cases.
■
Precaution on using the contact signal
Before using this contact signal, provide a contact protection measure (to absorb surge) suitable to
the using method. Failure can not only cause malfunction of the circuit being connected later but
also break the contact of the tester.
The Fig.3-14 and Fig.3-15 are the examples of the contact protection method recommended.
TOS8870A
Less than
30 V
BUZZER
Closed when FAIL alarm is generated
Less than 1 A
TOS8870A
100 VAC
Closed when test is on
Less than 1 A
LAMP
TOS8870A
a
V+
L
"L"when signal
is on.
