A self adjustable back up alarm is a speech device that converts audio signals into sound signals. Widely used in household appliances, banks, alarm systems, electronic toys, game consoles and other fields. The buzzer is mainly used to prompt or alarm. According to different design and use, it can emit music, whistle, buzzer, alarm, electric bell and other different sounds.
The self adjustable back up alarm used in washing machines often beep to remind users of the process. The buzzer used in most gas appliances will give an alarm to remind the user that the gas appliance is dry burning. As a doorbell app, the buzzer often makes a "ding dong" or musical sound to remind guests to visit. The self adjustable back up alarm installed in the public security, bank, family alarm area often gives an alarm sound. If someone enters the alarm area, the buzzer will give an alarm sound under the control of the sensor. The self adjustable back up alarm used in factories and schools often sound electric bells.
Since the self adjustable back up alarm is driven by dc voltage, it does not need to be driven by AC signal. Just output the drive level to the drive port and amplify the drive current through the audion to make the self adjustable back up alarm sound. In the SCM software setting, there are several system registers used to set the OUTPUT of PWM port, you can set duty cycle, cycle and so on. After these registers are set to generate the frequency waveform that meets the requirements of the self adjustable back up alarm, the PWM output port can output the square wave of the frequency as long as the PWM output is turned on.