Diodes or switch - neither one regulates the amount of energy passing to the load; they only control which source is providing it.
For a normal electronic device or circuit, the device requires a certain voltage to operate correctly. When connected to a power source of that voltage, it draws current from the source. The anound of current it draws is controlled by the parameters of the device, *not* the power source. This is why a car battery can run both the radio (1 amp) and the starter motor (50 amps) with straight wire connections. Power source > on/off switch > load.
With two power sources, there are several options for connecting them to a single, common load device. these have been discussed above. Without getting into fuses, fuseble resistors, current limiting circuits, etc., it is pretty straightforward. You pick which source is connected to the load, and the load decides how much current it will draw from that source.
In this scenario, you can overload the circuit by increasing the source voltage to an unsafe value. For example, if you connect a 12 V pump motor to 100 V, the motor probably will overspeed and burn up. But as long as the power supply, battery, and load device all are specified for the same voltage, there should be no problems as you switch between the two sources.
ak
For a normal electronic device or circuit, the device requires a certain voltage to operate correctly. When connected to a power source of that voltage, it draws current from the source. The anound of current it draws is controlled by the parameters of the device, *not* the power source. This is why a car battery can run both the radio (1 amp) and the starter motor (50 amps) with straight wire connections. Power source > on/off switch > load.
With two power sources, there are several options for connecting them to a single, common load device. these have been discussed above. Without getting into fuses, fuseble resistors, current limiting circuits, etc., it is pretty straightforward. You pick which source is connected to the load, and the load decides how much current it will draw from that source.
In this scenario, you can overload the circuit by increasing the source voltage to an unsafe value. For example, if you connect a 12 V pump motor to 100 V, the motor probably will overspeed and burn up. But as long as the power supply, battery, and load device all are specified for the same voltage, there should be no problems as you switch between the two sources.
ak