Pin transformerThe design process includes five processes: ① to clarify the turns ratio of the primary secondary coil; ② to clarify the turns of the primary secondary coil; ③ to clarify the wire diameter of the winding transmission line and cable; ④ to clarify the number of shares of the winding transmission line; ⑤ to carry forward the total area of the dialog box.
(1) Primary and secondary side transformation ratio
In order to improve the utilization rate of high-frequency transformer, reduce the current of the switch tube, reduce the reverse working voltage of the output rectifier diode, reduce the loss and control cost, the primary and secondary side transformation ratio of the high-frequency transformer should be as large as possible.
(2) the primary side and secondary side of the coil turns
The first selection of transformer skeleton. In order to reduce iron loss, according to the switching frequency of the power supply and referring to the raw material guide of the transformer skeleton, the maximum magnetic density in the work, the reasonable magnetic absorption cross section of the transformer skeleton and the total area of the dialog box can be clearly defined. According to the number of secondary coil turns and transformation ratio, the number of primary coil turns can be calculated.Pin transformer
(3) Clarify the diameter of the winding transmission line and cable
In the use of transmission line cable diameter, to take into account the transmission line skin effect. To put it bluntly, the skin effect means that when the transmission line passes through the AC circuit, the current flow on the cross section of the transmission line is uneven, with a small current intensity in the middle and a large current intensity at the edge, thus reducing the total area of reasonable conductivity of the transmission line and increasing the resistor. Under the DC standard, the skin effect is less harmful, and it is very harmful at high frequencies. The reduction of the total area of reasonable conductivity of transmission lines is generally indicated by deep layers. To put it bluntly, through the deep layer refers to the axial deep layer when the current intensity is reduced to the 0.368 of the current intensity on the surface of the transmission line. For the magnetic permeability of the transmission line, the relative magnetic permeability of copper is, that is, the magnetic permeability of copper is the magnetic permeability in the vacuum pump, for the electrical conductivity of the transmission line, and the electrical conductivity of copper is.
In order to reasonably use transmission lines and reduce the harm of skin effect, it is generally stipulated that the cable diameter of transmission lines is less than twice the penetration depth. If the cable diameter of winding resistance exceeds the larger cable diameter decided by the penetration depth, multi-core transmission lines with small cable diameter can be selected and wound or flat and wide copper skin can be selected to coil inductance, and the thickness of copper skin should be less than twice the penetration depth.lead type transformer
(4) Number of transmission line stocks with clear winding
The number of transmission line shares in the winding is determined by the larger magnitude of the current passing through the winding and the transmission line cable diameter. After taking into account the skin effect to clarify the cable diameter of the transmission line, we calculate the larger value of the current through the winding resistance.
The number of transmission line shares with the primary winding resistance: the number of transmission line shares with the primary winding resistance of the transformer is the highest effective value, then the number of transmission line shares with the primary winding resistance (in the formula, J is the current intensity of the transmission line, generally J = 3~5, which is the total conductive area of each transmission line.
The number of conductive strands of secondary winding resistance: ① full bridge method: the transformer has only one secondary winding resistance. according to the correlation of the primary and secondary current flows of the transformer, the highest effective value of the secondary current is: ② half-wave method: the transformer has two secondary winding resistances, and each load winding resistance respectively shows the load current flow for one and a half cycles, so its amplitude is (the highest value of output current flow). Therefore, the number of transmission line shares for secondary side winding is.rice cooker transformer
(5) Total Area of Carry-forward Dialog
After estimating the turns of the primary and secondary coils of the transformer, the wire diameter of the transmission line cable and the number of shares, be sure to check whether the total area of the dialog box of the transformer skeleton can be wound down or whether the dialog box is too large. If the total area of the dialog box is very small, it indicates that the transformer skeleton is very small, and a larger transformer skeleton should be selected. If the total area of the dialog box is too large, it indicates that the transformer skeleton is very large, and a smaller transformer skeleton can be selected. After re-selecting the transformer skeleton, re-calculate until the selected transformer skeleton foundation is suitable.