CIC2851E refrigerator closed remind schematic

Description: The CIC2851E refrigerator closed circuit principle involves a step-down regulator rectifier circuit, a delay circuit, a music IC (CIC2851E), speakers, and additional components. The buck regulator circuit provides a DC voltage of approximately 3V for the entire rectifier circuit. When the refrigerator door is opened, the AN switch is activated, causing capacitor C3 to charge through resistor R3. As the charging progresses, the base potential of transistor BG1 rises. After a delay of about 20 minutes, the voltage on C3 activates BG1, which in turn triggers BG2 and the CIC2851E. The output music signal is amplified by BG3 to drive a speaker, producing a sound to remind the owner to close the refrigerator door. If the door remains open, the music continues to play. The length of the delay time can be adjusted based on the duration of food access, typically ranging from 5 to 15 seconds, with this circuit set to 20 seconds. The required voltage across the circuit is approximately 3V; higher voltages can damage the integrated circuit. Resistor R6 is used to adjust the rhythm speed of the music, with values ranging from 20k to 120k ohms.

The CIC2851E refrigerator reminder circuit is designed to enhance energy efficiency and prevent food spoilage by alerting users when the refrigerator door is left open. The circuit architecture begins with a step-down regulator that converts the AC voltage from the power supply to a stable 3V DC output. This is crucial for powering the integrated circuit and associated components without risking damage from overvoltage.

The operation of the circuit is initiated by the AN switch, which is mechanically linked to the refrigerator door. Upon opening the door, the switch closes, allowing current to flow and charging capacitor C3 through resistor R3. The charging time of C3 is critical, as it determines the timing of the alert. The base of transistor BG1 receives the increasing voltage from C3, which eventually reaches a threshold that activates BG1. This transistor acts as a switch, allowing current to flow to BG2 and the CIC2851E music IC.

The CIC2851E is responsible for generating the audio signal that alerts the user. The output from this IC is then amplified by transistor BG3, which drives the speaker. The choice of speaker is important; it should be capable of producing a clear sound at the desired volume level to ensure the alert is heard.

The delay time for the circuit can be adjusted to suit user preferences, which is particularly useful in scenarios where the user may need to access the refrigerator for varying durations. The delay can be fine-tuned using a variable resistor, allowing for a range of 5 to 15 seconds, with the current design set to 20 seconds.

Resistor R6 plays a dual role in the circuit: it not only limits the current to the music IC but also adjusts the rhythm of the music output. The resistance values between 20k and 120k ohms allow for customization of the alert tone, making it more pleasant or attention-grabbing based on user preference.

Overall, this circuit serves as a practical reminder system that enhances the functionality of a refrigerator while promoting energy conservation and food safety. CIC2851E refrigerator closed circuit principle reminders The circuit consists of step-down regulator rectifier circuit, the delay circuit, music IC CIC2851E, speakers and other components. Where the buck regulator circuit for the entire rectifier circuit provides DC voltage of about 3V. When you open the refrigerator door, AN switch is turned on, the capacitor C3 is charged by R3, as charging progresses, BG1 base potential rise, about 20 minutes after the delay, so that the voltage on C3 conduction BG1, BG2 deadline, respective trigger CIC2851E work, the output of the music signal after amplification BG3 Y drive a speaker issued a bell sound bite whistle. music to remind the owner quickly closed. Refrigerator door is not closed, the sound of music more than. The length of delay time can be selected according to the access to food, generally between 5 to 15 seconds.

This circuit takes 20 seconds. DW required voltage across the circuit is approximately 3V, if too high, easy to damage the integrated circuit. Resistor R6 to adjust the speed of the rhythm of the music, which ranges from 20k R6 120k .