In order to check the power supplies there is an electronic load. This device works on the principle of signal generation. The main parameters of the modifications should include the threshold voltage, permissible overload, as well as the dispersion coefficient. There are several types of devices. In order to understand the loads, it is first recommended that you familiarize yourself with the circuit diagram of the device.
Modification scheme
A standard load circuit includes resistors, a rectifier, and modulator ports. If we consider devices of low frequency, then they use transceivers. These elements work on open contacts. Comparators are used to transmit the signal. Recently, stabilizer loads are considered popular. First of all, they are allowed to be used in a direct current network. They have a quick conversion process. It is also worth noting that an amplifier and regulator are considered an integral element of any load. These devices are closed on the lining. They have a fairly high conductivity. It is the modulator that is responsible for the generation process in the models.
Types of modifications
Distinguish between pulse and programmable devices. Laboratory ones are suitable for a separate category, which are suitable for powerful power supplies. Also, the modifications differ in the frequency with which they work. Low-frequency loads are equipped with transistors with a channel adapter. They are used on AC power. High-frequency models are made on the basis of an open thyristor.
Impulse devices
How is pulsed electronic loading done? First of all, experts recommend choosing a good thyristor for assembly. In this case, the modulator is suitable only for two phases. Specialists say that the expander should work alternately. Its operating frequency is required to be approximately 4000 kHz. The transceiver in the load is installed through the modulator. After soldering the capacitors, it is worth doing an amplifier.
For stable operation of the load, three channel-oriented filters will be required. A tester is used to test the device. Resistance should be approximately 55 ohms. With an average load, a home-made electronic load produces a rated voltage in the region of 200 watts. Comparators are used to increase sensitivity. With system short circuits, it is worth checking the circuit from the capacitor. If the resistance at the contacts is underestimated, then the transceiver must be changed to a capacitive analog. Many experts point to the possibility of using wave filters, which have good conductivity. Regulators for these purposes are used on the triode.
Programmable models
Electronic programmable load is fairly simple to assemble. For this purpose, an expansion transceiver of 230 V is used. Three contactors that depart from the transistor are used to transmit the signal. Regulators are used to control the conversion process. The most commonly used are linear analogues. The triode is used with an insulator. In this case, a blowtorch is required. Directly, the resistor is fixed on the transceiver.
For the model, conventional comparators with a low dispersion coefficient are not suitable. It is also worth noting that many make the mistake of installing one filter. For normal operation of the Prior only capacitive analogues are used. The rated output voltage should be approximately 200 V with a resistance of 40 ohms. If you assemble devices on a single-junction expander, then linear models are not suitable.
First of all, the device will not work due to the large overload of the thyristor. It is also worth noting that the model will require a line modulator with low sensitivity. Some specialists 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
Do-it-yourself laboratory electronic load is assembled with a powerful thyristor. Resistors are used with capacities from 40 pF. Experts say that capacitors can only be used expansion type. Particular attention during assembly should be paid to the modulator. If you use a wired analog, then for the load you will need three filters. A simple electronic load has a phase-type modulator with conductivity from 30 microns. The resistance is approximately 55 ohms. It is also worth noting that the loads often add up to a switched transceiver. The main feature of such devices is high ripple. In this case, the conductivity is provided at around 30 microns.
Field effect transistor device
The electronic load on the field effect transistor is done only on the basis of the comparator, and the thyristor is used of an adjustable type. When assembling, first of all, it is worth choosing a capacitor block, which plays the role of a pulse generator. In total, three filters will be required for modification. The resistor is installed behind the plates. Experts say that the electronic load on the field effect transistor produces 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 rated voltage for this type of load is not more than 400 watts. Experts say that the cover should be fixed behind the resistor. If we consider the high-frequency model for power supplies at 300 V, then the modulator will require a wave type. In this case, a tetrode is installed behind the thyristor.
Continuous current model
The electronic load circuit with infinitely adjustable current includes one thyristor. Capacitors for the model will require an expansion type with low conductivity. It is also worth noting that one amplifier is placed in the load. The most commonly used wave counterparts, which have a phase adapter. The regulator is installed directly behind the modulator, and the rated voltage should be about 300 watts.
Simple electronic load with infinitely adjustable current has two contactors for connection. Thyristors can sometimes be used on plates. Comparators in devices are installed with and without stabilizers. In this case, a lot depends on the operating frequency. If this parameter exceeds 300 kHz, then it is better not to install a stabilizer. Otherwise, the sieving coefficient will increase significantly.
TL494 based device
The TL494-based electronic load is fairly simple to assemble. Resistors for modifications are selected line type. They usually have a high capacity. And they are able to work in a direct current network. When assembling the model, the thyristor is used on two plates. TL494 electronic pulse load works with a phase or pulse type expander.
The most common is the first option. The rated voltage at the loads starts from 220 watts. Filters are used of the full type, and the conductivity is not more than 4 microns. When installing the regulator, it is important to evaluate the output impedance. If this parameter is not constant, then an amplifier is used for the model. Contactors are installed with and without adapters. The output voltage in the circuit is approximately 300 watts for the loads. When the devices are turned on, the current often rises. This happens due to the heating of the modulator. The user is able to avoid this problem by reducing sensitivity.
100 W models
An electronic load (circuit shown below) per 100 watts involves the use of two channel thyristors. The transistor in models is often used on an expansion basis. His 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. For self-assembly, wave comparators are additionally used. Home-made devices produce a voltage of not more than 300 V, and the operating frequency starts from 120 kHz.
200 W devices
An electronic load of 200 W includes two pairs of thyristors that are connected in pairs. Many models use low frequency wired 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 wire filters.
The transceiver should be installed behind the plates. In this case, the load voltage is approximately 400 V. Specialist say that devices on wire transceivers do not work well. They have low conductivity, there are problems with overheating. If voltage surges are observed, it is worth changing the comparator. Another problem may be the resistor.
How to make a device at 300 watts?
An electronic load of 300 W involves the use of two phase-type thyristors. The rated voltage of the devices is approximately 230 watts. The overload indicator in this case depends on the conductivity of the comparator. With self-assembly of this device, a channel-type modulator is required. A blowtorch is used to install the element.
Regulators are often used with an adapter. The relay is installed low impedance type. The dispersion coefficient of a home-made modification is approximately 80%. It is also worth noting that contactors are used with low sensitivity. How to check the load before turning on? This can be done with the help of a tester. The output voltage of home-made devices, as a rule, is 50 ohms. If we consider models with one comparator, then this parameter can be underestimated for them.
Models for 10 A blocks
The electronic load for a 10 A power supply is collected using an expansion thyristor. Transistors are often used at 5 pF, which have low conductivity. It is also worth noting that experts do not recommend the use of linear analogues. They have a low sensitivity. They greatly increase the dispersion coefficient. Contactors are used to connect to the unit. Modulators are often used with adapters.
If we consider the circuit on the capacitor block, then their frequency is on average 400 kHz. Sensitivity may vary. Contactors are often fixed to the modulator. Stabilizers should be used on two plates. It is also worth noting that a pole resistor is required to assemble the modification. It greatly helps to increase the pulse generation rate.
Devices for 15 A blocks
The most common are the loads for 15 A blocks. They use open resistors. In this case, transceivers are used in different polarity. In addition, they differ in sensitivity. On average, the voltage of the devices is 320 V. The models differ in conductivity. For the purpose of self-assembly, comparators on regulators are used. Before starting their installation, stabilizers are attached.
Experts say that expanders can only be installed through the lining. Input conductivity is required to be no more than 6 microns. When installing the regulator, the comparator is carefully cleaned. If you assemble a simple model, then the modulator can be used inverter type. This will greatly increase the dispersion coefficient. The threshold voltage is on average 200 V. The permissible power parameter is not more than 240 watts. It is also worth noting that different types of filters are used for the load. In this case, much depends on the conductivity of the comparator.
Device Diagram for 20 A Blocks
The electronic load (circuit shown below) for 20 A blocks is based on binary resistors. They maintain stable high conductivity. The sensitivity in this case is approximately 6 mV. Some modifications are distinguished by a high overload parameter. Relays for models are used on wave transistors. Comparators are used to solve conversion problems. Extenders are often found in phase type. And they can have several adapters. If necessary, the device can be assembled independently. For this, a capacitor block is used.
The rated voltage for homemade loads starts from 300 W, and the frequency averages 400 kHz. Experts do not recommend the use of transitional comparators. Regulators are used with linings. An insulator is required to install the comparator. If we consider the loads on two thyristors, then filters are used there. On average, the module capacitance is 3 pF. The dispersion rate for home-made models starts at 50%. When assembling the device, special attention should be paid to the adapter for connecting to the power supply. Contactors are pole type. They must withstand large overloads and not overheat.
AMETEK devices
Loads of this brand are distinguished by low conductivity. They are great for 15 A power supplies. Among the models of this company there are many impulse modifications. Their longitudinal overload is not high, but a high pulse generation rate is ensured. Specialists primarily note the good security of the elements. They use several filters. They deal with phase noise that distorts signals.
If we consider high-frequency models, then they have several thyristors. It is also worth noting that modifications on wire comparators are presented on the market. Based on the usual load of this brand, you can 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 frequencies. It is also worth noting that laboratory modifications are presented on the market. They have a fairly low dispersion coefficient. Models are often used in a switched type. The overload indicator averages 20 A. Protection systems are used in different classes. There are impulse models on store shelves. They are well suited for testing computer power supplies. Extenders in devices are used with linings.
ITECH Series
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 on average operates at a frequency of 200 kHz. The overload in this case is 4 A. The amplifiers in the devices are used with contact adapters. Thyristors are used phase or code type. Among the models in this series 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
Do-it-yourself electronic loading based on this transistor is quite simple. The standard model circuit includes two capacitor units and one expander. It should be noted right away that models of this class are well suited for 10 A power supplies. The voltage parameter for loads is 200 watts. Filters for devices are selected low frequency. They are able to work under heavy loads.
First of all, a thyristor is installed during assembly, and a different type of comparator can be used. Directly, the transistor is installed using a soldering iron. If its conductivity exceeds 5 microns, then it is worth installing a dipole filter at the beginning of the circuit. Experts say that the electronic load on the transistor IRGS4062DPBF can be done with transitional comparators. However, they have a high dispersion coefficient.
It is also worth noting that the models in this series are only suitable for DC circuits. The permissible parameter for overloading devices is 5 A. If we consider devices on pulse comparators, then they have a lot of advantages. First of all, a high frequency catches your eye. 50 .
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