When the patch resistance is damaged, the same resistance value should be considered first, and then the size and power should be paid attention to. If the dimensions are inconsistent in small signal circuits, welding and installation will be more difficult. Therefore, the following points should be noted when replacing the patch:
1) analog signal processing circuits, such as operational amplifier circuits, are used for input, output and feedback.
The positive value of the feed resistance is strictly required, and the positive value should be the same when replacing, and the difference should not be too big, otherwise the generator circuit numbered 1 will not work normally.
2) The positive value of the patch resistance used in digital circuits has a certain range, as long as the signal voltage changes obviously and meets the requirements of high and low levels. Practical maintenance
If there is no element with the same resistance, it can be replaced by an element with similar resistance.
Change, usually will not affect the circuit performance, such as 4.7kQ resistance damage, with.
5. 1KQ or 6.8KQ resistor can be used instead.
3) Replace with non-patched components. The damage rate of patch resistance is low. In general, if it is damaged, you can use a common resistor of 1/4W or 1/8W, but the resistance values should be the same or close. In addition, attention should be paid to the shaping of the pins during welding to make the pins as short as possible.