Basic interruptible Power Supply Circuit consist of regular power supply adapter and battery connection. This basic system is a “hot” battery connection, meaning that there is no switching mechanism in connecting and disconnecting the battery, the battery is always connected! This hot connection is very simple to implement and very robust because there would be no switching delay, the output voltage will be 100% continue if a power down happens, until the battery loose its capacity. The circuit schematic is shown below:
When the power line is normal, the current from the main adapter (transformer-rectifier diode bridge-filter capacitor) flow to the load through D3, and the battery is charged via R1 and D1. The diode D2 prevent the current at D3 output to be shorted by the empty battery in the normal power line condition. If the power down happens then the battery will supply the current to the load through D 2. Use a 15V AC output transformer for 12 volt lead acid battery. LED1 will indicate if the power line is normal. LED D1 will turn off if the power line is down.
Possibly Related Articles:
- 7.5V Uninterruptible Power Supply
This is 7.5V Uninterpretable Power Supply simple circuit. This circuit was used in many applications as a battery backup for low power requirements. This circuit contains a bridge rectifier, an... - Basic Symmetric Power Supply
The circuit below is the basic for standard symmetrical power supply. If your circuit need high current then this circuit is suitable. Here you can see the circuit’s schematic diagram.... - Simple 555 Switching Circuit Provides Negative Supply from Single Positive Supply
If you need a negative supply for op-amp or just need negative bias voltage while operating from a single supply voltage (for battery operation for example), this circuit helps providing... - Basic Vox Circuit Controls PTT
They were missing a VOX if we are take a look at some of the budget priced HF transceiver. It would certainly be nice to have VOX capability although most... - Lab Power Supply
This bench power supply circuit is suitable for your electronic experiment lab. This circuit can be built no on a piece of copper-laminate. The Bench Power Supply was designed to...
| 
