The wide voltage transformer is made as follows:
1. Determine Dmax and Vor.
2. Find the turns ratio n.
3. Find the primary inductance Lp.
4. Select the magnetic core.
5. Find the minimum number of primary turns.
6. Relationship between primary, secondary and feedback winding turns.
7. Select the wire length and determine the number of primary, secondary and feedback winding turns.
8. Make samples and adjust parameters.
Select the wire length and determine the number of primary, secondary and feedback winding turns. ?
The selection of wire diameter is calculated based on the average current of 4~6A per square mm. Select the wire diameter and number of turns according to the copper window compromise. Try to keep the values ??of Np, Ns and Na as close to integers as possible.
Make samples and adjust parameters.
Samples must be made in accordance with relevant laws and regulations and must meet the laws and regulations of the product market. Including temperature rise, insulation level, safety regulations, EMI, EMC, etc.
Electromagnetic shielding (Ferrari shielding), the shielding between the windings cannot form a loop, one end is suspended, and the other end is connected to the cold ground of the primary or secondary (no point of sudden voltage change). The outermost (core outer shield) shield must form a loop and connect the node to cold ground on the primary or secondary. When winding the transformer, ensure that hot nodes (referring to nodes with sudden changes in voltage or current) are placed on the bottom layer.