东莞市沃格精密电器有限公司

Fuses spread to our household, but the type of fuse on the market is very frequent, to choose the fuse you need to understand the characteristics and features of the fuse itself, for the recovery of the fuse selection, which points we need special Pay attention to it?

Self-recovery fuse is an over-current electronic protection components, the use of polymer organic polymer in the high pressure, high temperature, vulcanization reaction conditions, mixed with conductive particles, after a special process from processing. It is customary to call PPTC a self-healing fuse. The main role of self-recovery fuse is used to do the power protection role in the electrical. So since the recovery fuse with voltage, flow resistance, maintenance current, action time and other parameters. Therefore, in the self-recovery fuse selection is based on the product used in the voltage, current and protection current to select the appropriate product. Methods as below:

1. First determine the protection of the circuit to work the maximum ambient temperature, the circuit operating current, the maximum operating voltage, the required protection current, operating time and other parameters.

2. Select the applicable self-healing fuse according to the characteristics of the protected circuit or product. Is the plug-in fuse or patch fuse.

3. Select the product series with the withstand voltage rating greater than or equal to the maximum operating voltage according to the maximum operating voltage.

4. According to the maximum working temperature of the circuit and the operating current in the circuit, the self-recovery fuse temperature reduction rate is selected to maintain the current suitable product specifications.

5. According to the model of the self-recovery fuse action time curve to confirm whether the selected product meets the required action protection time.

6. Check the specifications provided in the data to confirm that the size of the thermistor size to meet the requirements.

For example, a control circuit requires overcurrent protection, its operating voltage is 48 volts, the circuit is working at a current of 450 mA, the circuit's ambient temperature is 50 ℃. Requires the circuit current to 1.4 amps to achieve protection and circuit 5 amp 2 seconds to the circuit can be quickly protected. We can choose according to its working voltage of 48 volts, first select the voltage level of 60 volts wh60 series of self-recovery fuse products, and then control the series of products to maintain the current and temperature relationship list select wh60-065 or wh60-075 two specifications of the product , And then according to the action time and current diagram found that 5 ampere wh60-065 and wh60-075 action time are about 1 second action time, but wh60-065 protection action current 1.3 amps does not meet the requirements, and thus The final choice should be wh60-075 specifications of the self-recovery fuse.

According to the above example can be seen, self-recovery fuse selection can be based on the above 6-step method for selection. But many of the requirements of the protection of the circuit is very complex, the specific selection or according to the specific circumstances of the selection after the most tested after the final test the final product.