Load electronic with their own hands: circuit. Self-made electronic load on the field effect transistor

To check power supplies, there is an electronic load. This device works by the principle of signal generation. The main parameters of the modifications include the threshold voltage, permissible overload, and also the dispersion coefficient. There are several types of devices. In order to understand the loads, first of all it is recommended to familiarize yourself with the circuit of the device.

Modification scheme

The standard load circuit includes resistors, rectifier and modulator ports. If we consider devices of small frequency, then they use transceivers. These elements work on open contacts. Comparators are used to transmit the signal. Recently, loads on stabilizers are considered to be popular. First of all, they are allowed to be used in a DC network. They quickly undergo a process of transformation. It is also worth noting that an integral element of any load is the amplifier and regulator. These devices close on the plate. They have a rather high conductivity. The modulator is responsible for the generation process for the models.

Types of modifications

Distinguish between pulse and programmable devices. A separate category is dedicated to laboratory, which are suitable for powerful power supplies. Also, modifications differ in the frequency with which they work. Low-frequency loads are equipped with transistors with a channel adapter. They are used in an alternating current network. Models of high-frequency type are made on the basis of an open thyristor.

Pulse devices

How is a pulsed electronic load done? First of all, for assembly, experts recommend choosing a good thyristor. The modulator is only suitable for two phases. Experts say that the expander must work alternately. The operating frequency of it must be about 4000 kHz. The transceiver is loaded into the load via a modulator. After soldering the capacitors, it is worthwhile to work on an amplifier.

For stable load operation, three channel filters are required. A tester is used to check the device. The resistance should be approximately 55 ohms. At an average workload, the self-made electronic load produces a nominal voltage in the region of 200 W. To raise the sensitivity, comparators are used. When closing the system, it is worth checking the circuit from the capacitor. If the resistance on the contacts is understated, then the transceiver needs to be changed to a capacitive analog. Many experts point to the possibility of using wave filters that have good conductivity. Regulators for this purpose are used on a triode.

Programmable models

Electronic programmable load is collected quite simply. For this purpose, an expansion transceiver of 230 V is used. Three contactors are used to transmit the signal, which depart from the transistor. To control the conversion process, regulators are used. The most frequently used are linear analogs. The triode is applied with an insulator. In this case, a blowtorch is required . Directly the resistor is fixed on the transceiver.

For the model, conventional comparators, which have a low diffusion coefficient, clearly do not work. It is also worth noting that many make the mistake of installing one filter. For the normal operation of the Prior, only capacitive analogs are used. The nominal output voltage should be approximately 200 V at a resistance of 40 ohms. If you assemble devices on an unijunctioned expander, then linear models are not suitable.

First of all, the device will not work because of the large thyristor overload. It is also worth noting that the model will require a low-sensitivity line modulator. Some experts use stabilizers when assembling. If we consider a simple modification, then an adjustable type is suitable. However, inverting elements are most often used.

Laboratory modifications

There is a laboratory electronic load with their own hands with a powerful thyristor. Resistors are used with a capacity of 40 pF. Experts say that capacitors can only be used in an expansion type. Pay special attention to the modulator when assembling. If you use a wired analog, then the load requires three filters. A simple electronic load has a phase modulator with a conductivity of 30 microns. The resistance is approximately 55 ohms. It is also worth noting that the load is often added on the basis of a switched transceiver. The main feature of such devices lies in high pulsation. In this case, the conductivity is ensured at a level of 30 microns.

Field FET Device

The electronic load on the field effect transistor is made only on the basis of a comparator, and the thyristor is used in an adjustable type. When assembling, it is first of all necessary to select a capacitor block, which plays the role of an impulse generator. In total, the modification requires three filters. Resistor is installed behind the plates. Experts say that the electronic load on the field effect transistor gives a resistance of 40 ohms.

If the conductivity is greatly increased, then a capacitive capacitor is installed. It is recommended to use the transceiver directly on two contacts. The relay is installed as standard with a regulator. The nominal voltage for loads of this type is not more than 400 W. Experts say that the cladding should be fixed behind the resistor. If we consider a high-frequency model for 300 V power supplies, the modulator will require a wave type. At the same time a thyristor is set up by a tetrode.

Model with continuously adjustable current

The electronic load circuit with continuously adjustable current includes one thyristor. Condensers for the model will require an expansion type with low conductivity. Also worth noting that the load is put one amplifier. The most frequently used wave analogs, which have a phase adapter. Directly the regulator is installed behind the modulator, and the nominal voltage should be about 300 W.

A simple electronic load with continuously adjustable current has two contactors for connection. Thyristors can sometimes be used on the plates. Comparators in devices are installed with and without stabilizers. In this case, much depends on the operating frequency. If this parameter exceeds 300 kHz, it is better not to install the stabilizer. Otherwise, the scattering coefficient will increase significantly.

Device based on TL494

The electronic load on the basis of TL494 is collected quite simply. Resistors for modifications are selected in the line type. As a rule, they have a high capacity. And they are able to work in a DC network. When assembling the model, the thyristor is applied to two plates. The electronic impulse load on the basis of TL494 works with an expander of phase or pulse type.

The most common is the first option. The rated voltage of the loads starts from 220 W. The filters are of the full type, and the conductivity is no more than 4 microns. When installing the controller, it is important to evaluate the output resistance. If this parameter is not constant, then the amplifier is used for the model. Contactors are installed with and without adapters. The output voltage in the circuit is about 300 watts. When the devices are turned on, the current often rises. This is due to the heating of the modulator. The user is able to avoid this problem by reducing the sensitivity.

100 W models

The electronic load (shown below) per 100 W assumes the use of two channel thyristors. The transistor for models is often used on an expansion basis. Its conductivity is about 5 microns. It is also worth noting that there are loads on the relay. They are most suitable for powerful power supplies. Wave comparators are also used for self-assembly. Homemade devices produce a voltage of not more than 300 V, and the operating frequency starts from 120 kHz.

200 W devices

The electronic load of 200 watts includes two pairs of thyristors, which are connected in pairs. Many models use wired low-frequency comparators. It is also worth noting that a modulator is required to assemble the modification. Amplifiers are used to speed up the process of signal generation. These elements are able to work only from wired filters.

The transceiver should be installed behind the plates. In this case, the load voltage is approximately 400 V. The specialist says that the devices on the conductor transceivers are not working well. They have low conductivity, there are problems with overheating. If there are jumps in voltage, it is worth changing the comparator. Another problem may be a resistor.

How to make a 300 W device?

The electronic load of 300 W involves the use of two phase-locked thyristors. The nominal voltage of the devices is approximately 230 watts. The overload indicator in this case depends on the conductivity of the comparator. If you build this device yourself, you will need a channel-type modulator. A blowtorch is used to install the element.

Regulators are often used with an adapter. The relay is set to low-resistance type. The dispersion coefficient for self-made modification is about 80%. It is also worth noting that the contactors are of low sensitivity. How to check the load before turning it on? You can do it with a tester. Output voltage for self-made devices, as a rule, equals 50 ohms. If we consider models with one comparator, then this parameter may be underestimated.

Models for 10 A blocks

The electronic load for a 10 A power supply unit is assembled using an expansion thyristor. Transistors are often used on 5 pF, which have low conductivity. It is also worth noting that specialists do not advise using linear analogues. They have little sensitivity. They greatly increase the diffusion coefficient. Contactors are used to connect the unit. Modulators are often used with adapters.

If we consider the circuit on the capacitor block, then they have an average frequency of 400 kHz. In this case, the sensitivity may vary. Contactors are often fixed behind the modulator. Stabilizers should be used on two plates. Also worth noting that to build the modification will require a pole resistor. It greatly helps to increase the rate of pulse generation.

Devices for 15 A units

The most common are loads for blocks of 15 A. They use open resistors. In this case, the transceivers are of different polarity. In addition, they differ in sensitivity. The average voltage of the devices is 320 V. Models differ in conductivity. For the purpose of self-assembly, comparators are used on regulators. Before starting their installation, stabilizers are attached.

Experts say that expanders can only be installed through the cover. Conductivity at the input must be no more than 6 microns. When installing the regulator, the comparator is carefully peeled off. If you assemble a simple model, then the modulator can be used inverter type. This greatly increases the coefficient of dispersion. The threshold voltage on the average is 200 V. The permissible power parameter is not more than 240 W. Also it is worth noting that for the load filters of different types are used. In this case, much depends on the conductivity of the comparator.

Diagram of devices for 20 A units

Electronic load (the scheme is shown below) for blocks of 20 A is made on the basis of binary resistors. They maintain a stable high conductivity. The sensitivity is approximately 6 mV. Some modifications are distinguished by a high overload parameter. Relays for models are used on wave transistors. To solve the problems with the conversion, comparators are used. Expanders often occur in a phase type. And they can have several adapters. If necessary, the device can be assembled independently. For this, a capacitor block is used.

The nominal voltage for self-made loads starts from 300 W, and the frequency on the average is 400 kHz. Experts do not recommend using transient comparators. Regulators are used with overlays. A comparator is required to install an isolator. If we consider loads on two thyristors, then filters are used there. The average capacity of the module is 3 pF. The dispersion factor for self-made models starts from 50%. When assembling the device, special attention should be paid to the adapter for connection to the power supply. Contactors are typing pole type. They must withstand large overloads and do not overheat.

AMETEK devices

Loads of this brand are distinguished by low conductivity. They are great for 15A power supplies. Among the models of this company there are many impulse modifications. They do not have a heavy overload, but a high speed of pulse generation is provided. Experts in the first place note the good security of the elements. They use several filters. They cope with phase interference, which distort signals.

If we consider high-frequency models, then they have several thyristors. It is also worth noting that the market presents modifications to wired comparators. On the basis of the usual load of this brand, it is possible to assemble an excellent device for different power supplies. The models have excellent stabilizers and very sensitive transistors.

Features of the Sorensen series

The standard electronic load of this series includes a thyristor and a linear comparator. Many models are manufactured with pole filters that are capable of operating at high frequency. It is also worth noting that laboratory modifications are on the market. They have a sufficiently low diffusion coefficient. Models quite often are of a commutated type. The overload indicator on average is 20 A. Security systems are used in different classes. On the shelves of shops there are impulse models. They are well suited for testing computer power supplies. Expanders in devices are used with overlays.

Models of the ITECH series

The loads of this series are distinguished by high conductivity. They have good security. In this case, several transceivers are used. The electronic load for the power supply unit operates on average at a frequency of 200 kHz. The overload in this case is 4 A. Amplifiers in devices are used with contact adapters. Thyristors are used in phase or code type. Among the models of this series there are programmable modifications. They are well suited for testing computer power supplies. Transceivers can be met with expanders and without them.

Loads based on IRGS4062DPBF

The electronic load is made by hand on the basis of this transistor is quite simple. The standard circuit of the model includes two condenser units and one expander. Immediately it is worth noting that the models of this class are well suited for power supplies at 10 A. The voltage at the loads is 200 W. Filters for devices are selected at a low frequency. They are able to work at high loads.

Firstly, a thyristor is installed during the assembly, and the comparator can be used of different types. Directly the transistor is installed using a soldering iron. If the conductivity is more than 5 microns, then it is worthwhile to install a dipole filter at the beginning of the circuit. Experts say that the electronic load on the transistor IRGS4062DPBF can be done with transient comparators. However, they have a high dispersion coefficient.

It is also worth noting that the models of this series are suitable only for direct current circuits. The permissible instrument overload parameter is 5 A. If we consider devices on impulse comparators, then they have a lot of advantages. First of all, a high frequency rushes into your eyes. At the same time, resistance devices are shown at a level of 50 ohms.

They have no problems with conductivity and sudden jumps in voltage. Stabilizers are allowed to use different types. However, they must operate in a DC circuit. Modifications without capacitors are still on the market. The scattering coefficient for them is about 55%. For devices of this class this is very small.

Devices based on KTC8550

Loads on the database of transistors are very appreciated among professionals. Models are great for testing small power units. The indicator of permissible overload, as a rule, is 5 A. Models can use different protection systems. When assembling the modification, it is allowed to use binary modulators with a conductivity of 4 microns. Thus, the devices will produce a large frequency at 300 kHz.

If we talk about the shortcomings, it is worth noting that the modifications are not able to work with power supplies at 10 A. First of all, there are problems with impulse jumps. Overheating of the capacitor will also make itself felt. To solve this problem, expanders are installed on the load. Triodes are usually applied with two plates and an insulator.