	The program - calculator is designed for the automated calculation of the magnetic chokes amplifiers (hereinafter MagAmp). The program allows you to reduce and simplify the work of an engineer – developer when designing the MagAmp chokes. The program is executed for three user-selectable groups of the magnetic cores produced by the PC Mstator. 
	MSSA-L -Series 
	These are the magnetic cores made of an amorphous cobalt-based alloy with annealing in a longitudinal field. Have very low losses and low coercive force (low control current).  Saturation induction is 0.6 T. Very high coefficient of squareness. Typical value is 0.98 (100 kHz). Temperature range is from - 60 to 100°C. 
	MSSA-N -Series
	The same cobalt-based amorphous alloy with annealing without field is used. They have the lowest losses and coercive force. Saturation induction is 0.6 T. Temperature range from - 60 to 100°C. They differ by a significantly lower coefficient of squareness, especially at lower frequencies (0.86 at frequency of 1 kHz, 0.96 at frequency of 100 kHz). This increases the so-called dead zone and requires a higher input voltage.
	MSSN -Series
	Cheaper nanocrystalline alloy with increased maximum induction 1.2 T. Extended operating temperature range from - 60° C  to 120° C. Good thermal stability. High coefficient of squareness. Typical value is 0.98 (100 kHz). The reduced sizes due to high induction. The alloy has higher losses and coercive force (control current) relatively to the amorphous cobalt-based alloys. The limited size range.

	MagAmp Application

	The magnetic amplifier chokes are mainly used in the multichannel pulse sources of power supply for independent separate stabilization of the output voltage, separate protection of the channels with a specific predetermined threshold of the output current, external separate output control voltage and current channels, the implementation of the stabilization mode for the output current or voltage. These are the miniature and very reliable devices that increase the stability of the output voltage (of all channels, not just the main one) and the efficiency of a switching power supply.
	 Read more http://www.mstator.ru/sites/default/files/pictures/orig/application.zip .

	Order of calculation

	1. Select the desired series of the magnetic cores.
	2. Configure the converter circuit. One-cycle circuit (forward converter) or two-cycle circuit. See the tab "Typical wiring diagrams".
	3. Choose the purpose of the MagAmp application. Only stabilization of the output voltage or with the ability to completely turn off the output (used for the purpose of separate protection of channels or when implementing the current source mode in chargers).
	4. Choose the type of winding. Single or multilayer. The multilayer winding allows the use of a cheap and small-sized magnetic core. This is the main option. A single-layer winding has a lower stray capacitance, which in some cases is important when implementing a control circuit.
	5. Set the output voltage Vo and the maximum output current of the load.
	6. Set the maximum input voltage Vin. This is the amplitude of the pulse at the input of the MagAmp choke. There is a certain minimum value at which a given output voltage is provided. This value depends on the frequency, number of turns, duty cycle, characteristics of the magnetic core and other factors. The program tentatively calculates this value, and if the user sets an insufficient value of the input voltage, replaces the entered value with the lowest possible calculated value.
	7. Set the conversion frequency in kHz.
	8. Set the duty cycle for the pulse sequence at the input of the MagAmp (from the output of the transformer).
        9. Set the window fill factor. It should be borne in mind that in some cases the value of 0.5..0.6 can be practically reached, but in others (thick wire and a small window) - 0.3..0.4. If it is practically not possible to perform (when winding) the resulting choke design, you can repeat the calculation with a lower fill factor. Too small value unnecessarily increases the size and price of choke.
	10. Set the direct maximum voltage drop across the VVD rectifying diode.
	11. Set the voltage drop across the winding of the inductor VL.
	12. Set the maximum value of the ambient temperature.
	13. Set the number of the magnetic cores in the package. The default value is 1. In some cases, if the program cannot find a suitable option, it is necessary to use more than one magnetic core.
	14. Set the expected temperature of the choke. This is a value that you would not like to exceed. The limiting value for cobalt alloys (MSSA-L, MSSA-N) is 100 degrees C, for the nanocrystalline (MSSN) 155 degrees C. The program looks through all the options for implementation, starting with the minimum size of the magnetic core. By default, the program will select the smallest magnetic core and price, for which the temperature of the choke will not be higher than the specified values. If you would like to have a choke temperature below the specified limit values, you can specify your limit, and the program will find an option that meets your requirements (if this option exists). As a rule, the lower the set operating temperature, the larger the size of the magnetic core.
	15. Set the permissible number of wires in the winding (for reasons of manufacturability) and the permissible range of current density.

	16. Press the button “Automatic selection of the magnetic core and its calculation”. The program will search for the smallest magnetic core, perform optimization according to the criterion of minimum losses for this magnetic core (a calculation cycle is performed with a sequential increase in the number of turns and a corresponding decrease in the diameter of the wire), and will give the calculation results. In the left column of the results - the design data of the inductor indicating the approximate dimensions, as well as the minimum and maximum value of the number of turns of the winding.           
	The minimum value is limited by the necessary flow to provide the required output parameters. The maximum – by the window area, wire diameter and the specified limit fill factor. In the right column of the results are the calculated values of the parameters. Please note that for the  option with shutdown, two control current values (Icontrol) and two operating temperature values are given. One value corresponds to the normal mode with the given output characteristics, and the other corresponds to the emergency shutdown mode (K3load). For a variant of a current source, it is possible to sequentially (several times) calculate the temperature of the inductor in the entire range of output voltages, changing only the value of the output voltage, and pressing the "Start optimization" button.
	The program optimizes the choke to minimize temperature in normal mode. Moreover, in shutdown mode, the temperature may exceed the permissible value. In shutdown mode, overheating is determined by losses in the magnetic core. Therefore, in the case when the choke temperature is obtained normal, and the temperature during shutdown exceeds the permissible, it is necessary to increase the number of turns in the "Optimization" group to obtain the acceptable temperatures or select a larger size of the magnetic core.
	17. After the automatic selection of the magnetic core (the program selects the magnetic core according to the minimum size and price criteria) and calculation, the user can manually select another magnetic core, using the buttons "Previous size" and "Next size", or select a specific magnetic core from the list. For each size, the program automatically performs the optimization procedure according to the criterion of minimum losses (Section 15). The choice of a different magnetic core may be required when an optimum is sought by another criterion, for example, by the minimum control current, maximum efficiency, minimum overheating, etc.
	18. In the "Optimization" group, the user has the opportunity to optimize the project for their task. For example, increase the number of turns in order to reduce the control current. Or recalculate for the available wire. In some cases, the shutdown temperature is too high. It can be reduced by increasing manually the number of turns.
	19. If the program does not find a solution for the one magnetic core, you can repeat the calculations by increasing the number of magnetic cores in the package.
	20. The program includes the size range and characteristics of the domestic PET-155 wire. For imported wires, there may be significant differences due to the higher resistivity.
	21. The final verification of the project and its refinement are carried out almost in a real scheme.

	The main work in the program takes place in the "Optimization" group.
Automatic calculation is used when choosing a different core or when changing any source data (outside the "Optimization" group) to obtain a starting point for optimizing the winding data of the inductor.

	 In the "Optimization" group, when changing the values using the arrows, the start of optimization begins automatically. But if the new value is entered "manually", then optimization should be started with the same button.

	Errors noticed, your questions, comments and suggestions can be sent to edf01@yandex.ru.