Constant resistance load:
In a constant resistance load the current will go down in proportion to the voltage drop as the resistance is fixed and the load must follow ohms law. Heaters approximate this type of load.
Constant current load:
In a constant current load the load will dynamically adjust its resistance as the voltage drops to keep the current constant. Thus as the battery voltage drops so will the equivalent resistance of the load. Older linear regulators using a pass transistor to deliver constant voltage to a fixed load powering electronics are this kind of load.
Constant power load:
In a constant power load, the dynamic resistance is adjusted to increase the current inversely to the load voltage. as the voltage rises or falls, then the product of voltage and current in the load is power which is constant. This is done to keep the power dissipated in the load constant as the voltage drops. Electronics devices with SMPS approximate this type of load as they generally employ regulators to generate a constant voltage and when then runs the electronics.
Real loads usually approximate one of the three types of load. Electrical engineers have as one of their tools electronics loads which can be programmed to emulate the load types above.
Source : Quora
In a constant resistance load the current will go down in proportion to the voltage drop as the resistance is fixed and the load must follow ohms law. Heaters approximate this type of load.
Constant current load:
In a constant current load the load will dynamically adjust its resistance as the voltage drops to keep the current constant. Thus as the battery voltage drops so will the equivalent resistance of the load. Older linear regulators using a pass transistor to deliver constant voltage to a fixed load powering electronics are this kind of load.
Constant power load:
In a constant power load, the dynamic resistance is adjusted to increase the current inversely to the load voltage. as the voltage rises or falls, then the product of voltage and current in the load is power which is constant. This is done to keep the power dissipated in the load constant as the voltage drops. Electronics devices with SMPS approximate this type of load as they generally employ regulators to generate a constant voltage and when then runs the electronics.
Real loads usually approximate one of the three types of load. Electrical engineers have as one of their tools electronics loads which can be programmed to emulate the load types above.
Source : Quora
