How is a switching power supply used for battery charging?
This is a charging method where batteries are charged with a constant current from beginning to end. A standard switching power supply is a constant voltage power supply, so it monitors fluctuations in output voltages, inputs the results in the control circuit, and executes constant voltage controlling also known as feedback controlling.
Can a battery be switched to an external power source?
A similar version of this article appeared in the May 13, 2002 issue of Electronic Design magazine. Portable equipment that can operate from a battery pack or an external power source (such as a wall-adapter or external supply) needs to be able to smoothly switch between the two power sources.
When to switch from battery to wall power?
It monitors the wall supply and switches from battery power to the wall supply only when the wall supply is stable and has been at or above U1’s trip voltage for a period of time. The battery will be back-driven (charged) during this delay period, which is typically 185mS.
How can I switch between two power sources?
Portable equipment that can operate from a battery pack or an external power source (such as a wall-adapter or external supply) needs to be able to smoothly switch between the two power sources. This application note describes a circuit ( Figure 1) that switches power sources with good efficiency and without switching noise.
What to do if your switch mode power supply fails?
Often SMPS include protection components such as additional resistor or Zener diodes to reduce damages in case of failure, but not always. Before going to far in replacing, make sure you check all the parts. For example, check if the controller IC still works.
What are the main causes of power supplies to fail?
The five main reasons power supplies fail – and what can be done about it 1. Fans. Fans are the number one failure mechanism of power supplies, as found by both military MTBF simulations as well… 2. Capacitors. Despite popular thought, a lot of progress is being made in capacitor technologies
What causes a power supply capacitor to fail?
Capacitors, especially electrolytics, can be found failed in many different failure states, including swollen, leaking, exploded, shorted, displaying reduced capacitance or increased in circuit ESR. Sometimes excess heat causes capacitor damage.