Is there any voltage at both ends of the current source? How to determine the direction of the voltage at both ends of the current source

Is there a voltage across the current source?

    An ideal current source can provide current to the outside, and the voltage at both ends is determined by the external circuit. In other words, there is also voltage at both ends of the current source, just like a voltage source provides voltage to the outside and there is also current in the voltage source.

    For example, if a 2A current source is connected to a 5 ohm resistor, the voltage at the current source terminal is 10V. If it is connected to a 10 ohm resistor, the voltage at the current source terminal is 20V.

How to determine the direction of the voltage across a current source

    The methods for determining the direction of the voltage at both ends of a current source include the current direction of a voltage source, the voltage direction of a current source, a controlled current source, and a controlled voltage source.

    The current value and direction of the current source remain unchanged. The voltage value and direction of the voltage source remain unchanged. The voltage direction of the resistor is consistent with the current direction. These can be directly concluded in the circuit. The current direction of the voltage source, the voltage direction of the current source, the parameters of the controlled current source and the controlled voltage source are determined by the component itself and the external circuit, and the answers must be obtained through calculation.

    The positive and negative poles of a current source are usually fixed, and will not change due to changes in the external environment. The voltage source in a normal discharge state has a + sign for the positive pole and a - sign for the negative pole, and the current flows out from the positive pole of the current source. Therefore, in general, we judge by the icon symbol, that is, the direction of the current source +/- sign.

    The voltage law across the ideal current is:

    The current of an ideal current source is constant. According to Ohm's law, the necessary condition for the formation of current is that there must be voltage and a loop. When the ideal current source forms a loop with the outside, a constant current can be output. Therefore, there must be voltage at both ends of the ideal current source. According to the principle of current and voltage direction correlation, its direction is the same as the current of the current source. It's just that the magnitude of the voltage will change with the change of external parameters.