Operation Description; Application Circuit - Holtek HT45F24A Quick Start Manual

Operation Description

The test key function description :

When the battery voltage is normal, the voice is "System normal".
When the low battery voltage is detected, the voice is "Please change the
battery".
When the smoke is deteced and the smoke detector alarms, the voice is "Fire",

the LED flashes 3 times for 50ms. The alarm time will last for 10s. If the test
key is pressed during alarm, the alarm is cancelled.
The smoke detecor will detect low voltage per 4s, when the low voltage is

detected, 3 steps are as follows :
Step 1. Play the voice "Please change the battery" once per 4s when the
◆
low voltage is detected, and play twice in total.
Step 2. The LED will flash 3 times for 50ms per 8s, a total of 8 cycles.
◆
Step 3. Play "Bi" warning tone for 3 times per 4s, jump to Step 1.
◆
Note: If the test key is pressed during low voltage, only the function in Step
2 is excuted.
Enter the test mode : long press the test key when power on, the system can

enter the test mode, which mainly is used to measure the second stage OPA
stability and sensitivity.

Application Circuit