How to measure 0 ohm resistor?
One, the action of 0 ohmic resistance.
On many circuit diagrams or on actual circuit boards, zero ohmic resistors are often encountered. Many maintenance workers are unaware of the effect of such resistors, and even think they have broken down short circuits when they are tested. Therefore, it is necessary to make a brief introduction to its role.
The common role of 0 ohmic resistors in circuits is shown in Table 1.
The main function of 0 ohmic resistance in the circuit.
Serial number | Function | Make it clear |
1 | Used to simulate the connection between a ground line and a digital ground line. | In the circuit, if the analog ground line and the digital ground line are connected directly in a large area, there will be mutual interference. In order to prevent interference, in addition to using magnetic bead connection, capacitor or inductance connection, usually 0 ohmic resistance is used to connect. When 0 ohmic resistance is used to connect, it is equivalent to very narrow current passing through, so the loop current can be effectively limited, thus the noise can be effectively suppressed. Resistance attenuates in all frequency bands (OQ resistance also has impedance), which is better than magnetic beads
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2 | Used for current circuits when crossing. | When the signal level is segmented, the shortest return path of the signal will be broken and the signal loop will have to bypass. The larger loop area will make the influence of electric field and magnetic field become stronger and form interference or be interfered. If the 0 ohmic resistance is crossed in the partition area, a shorter return path can be provided, thereby minimizing the interference. |
3 | Used to configure circuits. | In order to reduce maintenance cost, 0n resistance is usually used instead of jumper wire welding on the circuit board in order to reduce maintenance cost, it is usually required to reduce jumper and dial switch as far as possible. The empty jumper is equivalent to antenna at high frequency, and the effect of patch resistance is better. |
4 | Insurance. | In the power supply circuit, when the part of the power supply is short-circuit fault, such as the series connection of the 0Q resistance in the circuit, then the 0Q resistance will burn out first because of the small power, thus effectively protecting the other components from being damaged. |
5 | Other effects. | 1 wiring as a cross-wiring; 2 as a debugging or test point of cross-wiring; 3 as a temperature compensation device. |
Two, 0 ohmic resistance detection method.
When a multimeter is used to detect 0 ohmic resistance, it is exactly the same as that of ordinary resistors, but the Rx1 block of multimeter should be used, and the measured resistance value is equivalent to the on and off condition of detecting conductor. If the detected resistance value is 0 ohms, then the detected 0 ohmic resistance is basically normal, if the detected resistance value is large or ∞, then the detected 0 ohmic resistance is bad or damaged, the new part should be replaced.
It must be noted that due to the special role of 0 ohmic resistance in the circuit, when it is damaged, in many cases, the wire can not be directly replaced, which should be paid special attention when repairing and replacing.