Stabilizer: designation, description, schemes

Modern man is constantly surrounded by a huge amount of electrical equipment, both domestic and industrial. It is difficult to imagine our life without electrical appliances, they have imperceptibly penetrated into the houses. Even in our pockets there are always several such devices. All this equipment for its stable operation requires uninterrupted power supply. In fact, jumps of mains voltage and current most often cause the equipment to fail.

To ensure high-quality power of technical devices, it is best to use a current stabilizer. It will be able to compensate for the network drops and extend the service life.

The current stabilizer is a device that automatically maintains the consumer's current with a specified accuracy. It compensates for the jumps in the frequency of the current in the network, the change in the load power and the ambient temperature. For example, increasing the power consumed by the device will result in a change in the current consumed, which causes a voltage drop across the source resistance, as well as the wiring resistance. The larger the internal resistance value, the stronger the voltage will change with increasing load current.

The compensation current regulator is a device with automatic control, which contains a negative feedback circuit . Stabilization is achieved as a result of changes in the parameters of the regulating element, in the event of a feedback pulse acting on it. This parameter is called the output current function. By the form of regulation, the compensation current stabilizers are: continuous, pulsed and mixed.

Main settings:

1. Stabilization factor based on the value of the input voltage:

To _st.t = (ΔU _in / ΔI _H ) * (I _H / U _in ), where

I _н , ΔI _н - current value and increment of the current value in the load.

The coefficient K _{stt is} calculated with the load resistance unchanged.

2. The value of the stabilization factor in the case of a change in resistance:

K _{R H} = (ΔR _n / R _H ) * (I _H / ΔI _H ) = R _i / R _{H, where}

R _H , ΔR _н - resistance and increment of load resistance;

G _i is the value of the internal resistance of the stabilizer.

The coefficient K _{R H is} calculated with an unchanged input voltage.

3. The value of the temperature coefficient of the stabilizer: γ = ΔI _n / Δt _okr.

The energy parameters of the stabilizers include the efficiency: η = P _out / P _in.

Let us consider some stabilizer schemes.

Very widely used was the current stabilizer for a field-effect transistor, with a shorted gate and source, respectively, U _cu = 0. The transistor in this circuit is connected in series with the load resistance. The points of intersection of the direct load with the output characteristic of the transistor will determine the current value at the smallest and largest value of the input voltage. When using such a circuit, the load current changes insignificantly with a significant change in the input voltage.

The pulsed current regulator has its distinctive feature of the work of the transistor-regulator in the switching state. This allows to increase the efficiency of the device. The pulsed current regulator is a kind of a single-cycle converter covered by a negative feedback loop. Such devices, depending on the implementation of the power part, can be divided into two types: with a serial connection of the throttle and the transistor; With a series connection of the throttle and a parallel connection of the regulating transistor.