Search results
Results from the WOW.Com Content Network
Conversely, a current source provides a constant current, as long as the impedance of the load is sufficiently lower than the current source's parallel impedance (which is preferably very high and ideally infinite). In the case of transistor current sources, impedances of a few megohms (at low frequencies) are typical. Because power is current ...
A constant current source circuit constructed with LM317. The device can be configured to regulate the current to a load, rather than the voltage, by replacing the low-side resistor of the divider with the load itself. The output current is that resulting from dropping the reference voltage across the resistor. Ideally, this is:
English: Schematic of a 1A current regulator using LM317 adjustable voltage regulator. The open-circuit voltage assumes the output stage of the LM317 saturates at approximately 0.2 V and the adjust pin sinks enough current so that the voltage drop across the 1.25 ohm resistor is 1.25 V, which corresponds to the approximate temperature-compensated bandgap of silicon.
Closed-loop regulator circuits using the TL431 are always designed to operate in high transconductance mode, with I CA no less than 1 mA (point D on the current-voltage curve). [8] [7] [2] For better control loop stability, optimal I CA should be set at around 5 mA, although this may compromise overall efficiency. [30] [7]
A regulated power supply is an embedded circuit; it converts unregulated AC (alternating current) into a constant DC. With the help of a rectifier it converts AC supply into DC. Its function is to supply a stable voltage (or less often current), to a circuit or device that must be operated within certain power supply limits.
A current mirror is a circuit designed to copy a current through one active device by controlling the current in another active device of a circuit, keeping the output current constant regardless of loading. The current being "copied" can be, and sometimes is, a varying signal current.
A Wilson current mirror is a three-terminal circuit (Fig. 1) that accepts an input current at the input terminal and provides a "mirrored" current source or sink output at the output terminal. The mirrored current is a precise copy of the input current.
Non-ideal voltage source model (left) and non-ideal current source model (right) A generator in electrical circuit theory is one of two ideal elements: an ideal voltage source, or an ideal current source. [1] These are two of the fundamental elements in circuit theory. Real electrical generators are most commonly modelled as a non-ideal source ...