Cleverly use old switch power supply to replace low voltage power supply of induction cooker

Most of the low-voltage power supplies of induction cookers are 18V and 5V. In the repair of induction cookers, the damage of low-voltage power supplies accounts for a certain proportion. Whether it is a low-voltage power supply composed of discrete components, transformers, or power chips, after damage, due to the different transformation ratios of the transformer, or the power chips and components are not available for purchase at the moment, it will affect the progress of the repair.

In the maintenance practice, 100 5.3V/600mA output short-circuit switching power supplies were purchased for transformation and replacement. First, waste can be recycled, second, maintenance costs can be saved, and third, maintenance time can be shortened. The effect is good. Now introduce as follows: 1. Transformation

In fact, by only replacing one resistor of the switching power supply, the switching power supply with an output of 5.3V can be turned into a low-voltage power supply for an induction cooker (the secondary circuit of the old switching power supply is shown in the figure above. The schematic diagram of the component transformation is shown in the figure below). The specific method is: pry open the shell, take out the circuit board, remove the two voltage regulator tubes ZD1 and ZD2 of the power supply secondary and the two low-voltage electrolytic capacitors C8 and C9 (a filter capacitor with a voltage resistance of more than 25V can be installed at the C8 position, or it can be left uninstalled). The key is to change the resistance value of R14. For example, if R14 is replaced with 31kΩ, 12V can be obtained; if it is replaced with 45kΩ, 16V can be obtained; if it is replaced with 52kΩ, 18V can be obtained, etc. If the output voltage is slightly lower than the rated value after replacing the resistor, just scrape the resistor with a blade to increase the resistance value to reach the rated voltage value (it is possible as a courtesy repair - editor), and you don't need to replace the resistor.

2. Installation

After obtaining the stable voltage value required by the induction cooker, use two power cords of appropriate length to connect the 220V input line of the old switching power supply to the AC220V input line of the induction cooker respectively: at the same time, connect the low-voltage positive pole of the old switching power supply to the negative pole of the low-voltage 18V rectifier tube of the induction cooker: connect the negative pole of the old switching power supply to the negative pole of the original 18V filter capacitor of the induction cooker. For the 5V voltage required by the induction cooker, just use an 82Ω resistor, connect one end to 18V, and the other end to the 5V power supply input terminal of the induction cooker, and properly fix the old switching power supply circuit board to the empty space of the original low-voltage power supply of the induction cooker, and the installation work is completed. As long as the subsequent circuit of the repaired induction cooker is fault-free, the induction cooker can work normally.