Current stabilizer: purpose, description, diagrams

2024 Author: Trinity Chesterton | [email protected]. Last modified: 2024-01-02 00:28

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 quietly entered the house. Even in our pockets there are always a few of these devices. All this equipment for its stable operation requires an uninterrupted supply of electricity. After all, surges in the mains voltage and current most often cause the failure of devices.

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

A current stabilizer is a device that automatically maintains the current of a consumer with a given accuracy. It compensates for current frequency surges in the network, changes in load power and ambient temperature. For example, increasing the power drawn by a device will change the current drawn, causing a voltage drop across the source resistance as well as the wiring resistance. The greater the value of the internalresistance, the more the voltage will change with increasing load current.

The compensating current stabilizer is a self-adjusting device that contains a negative feedback circuit. Stabilization is achieved as a result of changing the parameters of the regulating element, in the event of a feedback pulse acting on it. This parameter is called the output current function. According to the type of regulation, compensatory current stabilizers are: continuous, pulsed and mixed.

Main parameters:

1. Input voltage stabilization factor:

K _st.t=(∆U _in /∆I_H) (I_H /U _{in), where}

I_n , ∆I_{n – current value and increment of current value in the load.}

K-factor _{st.t calculated at constant load resistance.}

2. The value of the stabilization coefficient in the event of a change in resistance:

K_RH=(∆R _n/ R _n)(I_H/∆I_H)=r_i / R_{H where}

R_H, ∆R _{n - resistance and load resistance increment;}

g_{i – internal resistance value of the stabilizer.}

K_{RH coefficient is calculated with constant input voltage.}

3. Temperature coefficient value of the stabilizer:

To energy parametersstabilizers refers to the efficiency: η=P _out/P _in.

Let's consider some schemes of stabilizers.

Very widespread is the current stabilizer on a field-effect transistor, with a shorted gate and source, respectively U_{zi=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 value of the current at the lowest and highest value of the input voltage. When using such a circuit, the load current changes slightly with a significant change in the input voltage.}

Switching current stabilizer has its distinguishing feature of the operation of the transistor-regulator in the switching state. This allows you to increase the efficiency of the device. A switching current stabilizer is a type of 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 series connection of a choke and a transistor; with a series connection of a choke and a parallel connection of a regulating transistor.