Connection of current transformers. Wiring diagram of current transformers

Transformers are electromagnetic devices. Their main task is the conversion of a direct current. This process is carried out by electromagnetic induction. To date, power and pulse transformers are being separated.

There are also many varieties of separation models. The counters, in turn, are divided into single-phase, two-phase and three-phase. The type, power and type of the meter will directly affect the connection of the transformer.

Connection to a single-phase meter

Connection of current transformers to a single-phase meter is usually carried out through a transistor. In this case, the stress parameter plays an important role. If we consider a 220/220 V pulse transformer, then it is connected using a beam transistor. The adapter will require a one-contact.

To lower the frequency, different types of capacitors are used. To date, the most common are the capacitive models. However, analog devices also have the right to exist. Direct connection of the converter is carried out after checking the negative resistance on the transistors.

How to connect to a two-phase counter?

Connection of current transformers to a two-phase meter is often carried out via a latitudinal transistor. However, if we talk about lowering models at 220 V, they can be connected only through capacitors with a large conductivity parameter. Transceivers in circuits are used quite often. With electromagnetic interference, they are struggling quite successfully.

To ensure that the transistor does not suffer a large overload, a stabilizer is used. Converters for connection can be found mainly in analog type. The negative resistance parameter in this case should not exceed 60 ohms.

Connection to a three-phase meter

Connection of current transformers to this type of meter is mainly via a discrete transistor. In stores they are presented with different conductivity parameters. If we consider a pulsed three - phase current transformer , then in this situation it makes sense to immediately put a two-contact converter.

In order not to cause failure in the circuit, high-capacitance capacitors are used. Direct connection to the meter is carried out through the throttle.

Linear transistor circuit

Connection of current transformers via a linear transistor can occur only when modulators are used. In this case, power transformers for connection do not fit uniquely. It is more expedient to select a two-pin adapter directly. In this case, many experts recommend installing an inverter. It should be located behind the transistor. However, before this, the negative resistance in the circuit is checked. A parameter of 55 ohms is considered normal. Exceeding it indicates that the converter is set to low-resistance.

Connecting the transformer through an operational transistor

The connection via an operational transistor can only be made to a single-phase meter. Characteristics of the transformer in this case do not play a special role. The problem sometimes lies in increasing the frequency of the converter. Condensers for the circuit are only used in an open type. The conductivity should be at least 6 microns.

Also pay attention to the parameter of negative resistance. If it exceeds 50 Ohm, then the risk of overheating of the converter is high. In this case, the switch is suitable even for two-pin.

Scheme with a conductor relay

Connection via a wire relay is quite simple. Characteristics of the transformer in this case do not play a special role. In this case, the adapter will not be required. Condensers many experts recommend putting an analog type. The converter, in turn, requires a low-resistance converter. Due to this, low frequency problems are rare. Before placing the capacitor, check the negative resistance on the transformer. The specified parameter must be less than 60 ohms. Otherwise, the capacitor can not stand.

Connection via transceiver

With the help of a transceiver, the meter connection via current transformers is carried out with single-ended transducers. If we consider pulse transformers, then the transistor will require an analog one. In addition, single-contact switches are used. In this case, the current conductivity should be at a level of 5 microns. If we talk about separating transformers, then the counters are suitable only for single-phase ones. The parameter of the limiting frequency in the circuit, as a rule, does not exceed 6 Hz. Converters in models are usually installed low-resistance. Due to this, transformer malfunctions are rare. At the same time, there is no heavy load on the adapter.

Also separately consider the connection of step-down transformers. They belong to the class of high-voltage devices. In this case, the operating frequency parameter in the circuit can reach 80 Hz. To deal with it, the converter must be installed one-contact. Transistors in this case are mainly radial. If we talk about a modification of 500 V, then in addition a small stabilizer is placed in front of the meter. To increase the current transmission, it will fit perfectly.

Use of auxiliary thyristors

With the aid of auxiliary thyristors, the connection of the meter via current transformers is carried out only when using single-contact type converters. However, if we talk about pulse transformers, then two-contact modifications can be used. In other cases, this is forbidden. Transistors for the circuit are used without a stabilizer. In this case, the connection to the meter is by means of a throttle. Also, many experts recommend installing semiconductor modulators to increase the frequency.

Application of the unijunctioned zener diode

Unijunctioned zener diodes are famous for being able to work perfectly with power transformers. Converters for these purposes are selected one-contact. If we consider a 220/220 V isolating transformer , then the stabilizer in this case should be installed near the counter. Modulators are mostly used analog. However, some prefer wave modifications.

With a maximum voltage of 300 V, they are considered more effective. They also significantly reduce the risk of failure in the transformer. Connection to single-phase meters is carried out by the throttle. In this case, the voltage can only withstand a two-wire type.

Connection via low-frequency comparators

Connection of current transformers to the meter is sometimes carried out through low-frequency comparators. The limiting voltage they withstand at a level of 500 V. Thus, the power transformers for the connection are good. However, lowering analogs can also be used. This requires a high-quality one-contact converter. Without a beam transistor in this situation can not do. Increase the capacity of the converter is possible only with the help of a stabilizer. The switch in such a circuit must be in front of the meter.

Use of high-frequency comparators

Through high-frequency comparators, the installation of current transformers can be carried out only to three-phase meters. In this case, the transistors are allowed to use only a magnetic type. The conductivity parameter in the circuit does not exceed 7 / i. The operating frequency is 80 Hz on the average. To increase the sensitivity, two-contact converters are used.

Radiation transistors are rarely used, because they cope with electromagnetic interference badly. If we talk about step-down transformers, then their connection can occur only with the participation of a powerful modulator. However, before connecting it, the negative resistance in the circuit is checked. In the end, it should not exceed 50 ohms.

Scheme with a constant tetrode

Constant tetrodes in the circuit do not allow the converter to burn, even if the limiting frequency exceeds 80 Hz. In this case, much depends on the type of transformer. If we talk about power devices, then the adapter can be safely taken single-contact. Converters often use analogue. Their conductivity should be no less than 7 microns.

The negative resistance in the circuit must not exceed 60 ohms. Speaking of step-down transformers, they can be connected through a tetrode only with single-phase counters. In this case, the transistor is used beam. In turn, modulators are installed wave. The output voltage parameter must not exceed 200 V.