Current Regulators

1amp Current Regulator:

The circuit is very simple yet promises huge application scope. As can be seen in the diagram the IC LM317 hardly incorporates any external components, just a couple of them (C1 and R1) to be precise. C1 ensures ripple filtration and smoothes the input DC. R1 is interestingly connected to the ADJ terminal of the IC so that its gets clamped with the released output current from the IC. This forces the ICís internal circuitry to monitor and control the output current to a level determined by the value of R1. Here the value ensures that the output current cannot rise beyond 1 Amp. Other values can be appropriately and proportionately worked in place of R1 for getting other desired control levels of the output current.

As the circuit is protected from invalid current levels, it becomes suitable for applications where operations at strict or critical current levels become imperative. The circuit can be also be used for charging cell phone batteries (cell phones), automobile batteries, Ni-Cd batteries, for driving green pointer lasers, and for driving vulnerable high efficiency white LED lamps.

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5A Constant Voltage / Constant Current Regulator

An outstanding circuit can be built using LM317 IC along with Lm301 IC and a handful of other passive components. The parts wired around LM301 helps to generate variable outputs featuring constant voltage and constant current levels at the respective adjusted values. Voltage is varied through R8 while R2 takes hold of the current adjustment operations. The diodes are included for providing extra safety to the ICs. The power transistor MJ4502 in association with R1 and R3 act as current sensor and amplifier, with maximum current capacity of 5 Amps. For acquiring higher output currents, the transistor, R1 and R3 may be adjusted proportionately. The transistor may require a heatsink. Other equivalent values like TIP32C, MJE2955, etc. may also be tried in place of the shown transistor type.

The application is best suited for building high end type power supply units with excellent specifications and as battery chargers for charging all types of lead acid or SMF batteries.

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