Voltage Regulator- It is defined as the circuit that supplies a constant voltage without any reference to the load currents in that particular circuit. The voltage regulator is used to maintain a constant voltage supply i.e. it takes a fluctuating voltage level. The main function of the voltage regulator is to generate stable dc voltage for powering desirable electronic circuits.
There are generally two types of the voltage regulator. They are termed as a series voltage regulator and switching voltage regulator.
1. For series voltage regulator- It is also known as a linear voltage regulator (or the series pass regulator) because it uses the power transistor connected in series form, between the uncontrolled dc input and the desired load in that particular circuit. The power transistor used in the series voltage regulator conducts in the active region.
Here, the linear region is also termed as a linear region (or ohmic mode). The main function of the series voltage regulator is to maintain the voltage drop between input and output as needed to achieve the required output voltage.
2. For switching voltage regulator- It is the most preferred voltage regulator as it is more efficient than the series type of voltage regulator. This type of voltage regulator is termed as switching voltage regulator as it contains a switch which is used to turn ON and OFF the voltage regulator. By using the switch, the required average current is delivered in periodic pulses to the load. It operates on the DC voltage supply and the outer voltage is very high. The switching voltage regulator is used when the power efficiency is critical.
Characteristics of the Switch power supply1. The most important characteristic of any switch power supply is the amount of power transmitted to the user device. In the switch power supply, the power transmitted across the device is in discrete pulses. Here, the flow of current is not in the steady flow.
2. Efficiency- it is defined as the useful power output divided by the total input power. The efficiency of the switch power supply varies from 70% to 90%. Therefore, the device has a greater efficiency.
3. If the device dissipates a small amount of average power, it is said to be effective. The voltage regulator dissipates only the very small amount of average power. Hence, it is preferred as it delivers no current and power when the device is in the cut-off region.
4. Operating frequency- It generally operates at 20 Kilo Hz and even faster. We should be very careful while using the switch power supply because the device is quite complex compared to another type of voltage regulators such as series or linear voltage regulator. We should also be very aware of electromagnetic and radio frequency interference while using it.
5. The important characteristic of switch power supply is that it allows the use of a small transformer, inductors, and capacitors. The main function of a small transformer is that it usually splits the magnetic circuit into two separate return ways on either side of the magnetic core.