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Low drop Principle of Linear Voltage Regulators

2017-03-07 05:57  
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This article is a linear low drop voltage regulator principle discussed. By convention, in order to better grasp the principles you are, we recommend you to combine text read schematics. The gate drive voltage generating circuit is required to use a MOSFET voltage doubler circuit by the diode D1 and D2 and capacitor C1 and C4. The MOSFET is fully, the gate terminal should be about more than 10 v source terminal is connected to the output here. Contributes to this voltage doubler gate voltage through resistor R1. Adjustable shunt regulator TL431  (IC2) is used here as the error amplifier, which dynamically adjusts the gate voltage at the output regulation. There is sufficient heat sink MOSFET, the circuit can provide up to 3 a slightly higher output minimal pressure drop. Trimpot VR1 is used to fine-tune the circuit output voltage. With capacitor C5 and resistor R2 provides compensation of the error amplifier. The circuit provides short-circuit protection components crowbar protection against accidental short of the stress in the output. This will work as a crowbar protection: Under normal operating conditions, the voltage of the capacitor C3 and diode D5 to 6.3 v in the off state, because it reverse bias voltage and the output voltage 12 v. However, the output is shorted, the output will be temporarily decreased, resulting in the photovoltaic element and the D5 triac MOC3011 (IC1) is triggered, the gate-to-ground voltage, thus limiting the output current. This circuit will remain locked in this state, and the input voltage must be switched off to reset the circuit. This circuit is shown in Figure 2 follow a similar scheme. It can be used when the regulator must work from a DC rail instead of 15 v-0-15v AC supply. Here's gate voltage generated using LM555 charge pump circuit is as follows: When the 555 output is low, capacitor C2 will be charged through diode D1 to the input voltage. In the next half cycle, when the output of 555 is improved, the capacitor C3 will be charged, almost twice the input voltage. This circuit is based on the linear regulator MOSFET with a voltage drop as low as 60 mV at 1 Amp. Less likely to drop better mosfet millivolts RDS () has a low resistance. This circuit in fig. 1 Use 15 v-0-15v two from the step-down transformer and employs an n-channel MOSFET IRF 540 to obtain regulatory 12 v output DC input, possibly as low as 12.06 v.
If you are a first reading on this principle, we recommend that you carefully read several times in order to better fully grasp this simple but effective circuit.

Ultra low drop linear voltage regulator

Ultra low drop linear voltage regulator

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