2012.01.04

7/7

FA2803P/F

Revision No : 0

Typical Application

Supply voltage circuit is connected as a previous diagram. Please decide constants R1, R2, C4, and C5 of

a filter in order to keep at least 12V in V+, when normal supply current flows.

In this case, please connect C4 (more than 1uF) and C2 (less than 1uF). ZCT and load resistance RL of ZCT

are connected between input pin① and ②. In this case protective resistance (R3=100Ω) must be inserted.

Sensitivity current is regulated by RL, and output of amplifier shows in pin④. External capacitor C1 between

pin④ and GND is used for noise removal.

When large current is grounded in the primary side (AC line) of ZCT, the waveform in the secondary side of

ZCT is distorted and some signal doesn’t appear in the output of amplifier. So please connect a varistor or

a diode (2 pcs) to ZCT in parallel.

Latch circuit is used to inspect the output level of amplifier and to supply gate current on the external SCR.

When input pin becomes more than 1.1V (Typ.), latch circuit operates and supply gate current in the gate of

SCR connected to the output pin⑦.

Pin⑥ can be used in the open state, but please connect capacitor (about 0.047uF) between pin⑥ and pin⑦.