Backup Supply Activates By Drop-In Main Supply

A supply monitor utilizing two TL7702A chips monitors the ±15-V supplies and activates the backup supply in the event of a voltage drop. While these chips are primarily designed for use as reset controllers in microprocessor systems, they are effective for this application.

The circuit employs two TL7702A voltage monitoring chips to continuously observe the ±15-V power supplies. Each chip is configured to detect any significant drop in voltage levels, which could compromise the functionality of connected electronic components. Upon detection of a voltage drop, the chips trigger a mechanism to engage a backup power supply, ensuring that the system remains operational and preventing potential data loss or damage to sensitive circuitry.

The TL7702A chips are designed with built-in hysteresis to prevent erratic behavior during voltage fluctuations. This feature ensures that the backup supply is only activated when necessary, thus conserving energy and prolonging the life of the backup components. The output from each TL7702A can be connected to a relay or a transistor switch that controls the backup power source, allowing for a seamless transition between the primary and backup supplies.

In addition to the voltage monitoring capabilities, the circuit may include additional components such as capacitors for filtering and stabilization, as well as resistors for setting the appropriate thresholds for activation. These components work together to create a robust supply monitoring solution that enhances the reliability of the overall system.

Overall, this supply monitor circuit represents a practical application of the TL7702A chips, showcasing their versatility beyond their intended use in microprocessor reset applications. This design is particularly beneficial in environments where power stability is critical, ensuring that systems remain operational during transient voltage conditions. A supply monitor using two TL7702A chips monitors the ± 15-V supplies and activates the back up supply in case of a voltage drop. Although the chips are intended for use as reset controllers in microprocessor systems, they work well in this application. 🔗 External reference