保持电源及开关稳定性
在开关电路中应用可控硅时，首先要注意电源及开关的稳定性。在电源方面，需要关注并避免出现交流电供电不稳定、三相不平衡、缺相和单相问题，同时要避免出现浪涌现象，这些都会影响电源的稳定性。开关方面的主要注意事项是接触不良，其中常见的接触不良原因是整流管损坏，因此要及时更换有问题的整流管。
保持电路电流稳定性
在常见的可控硅故障中，很多是由于整流二极管损坏或烧毁导致的。同样，整流部分的故障还包括电解电容击穿、桥堆击穿和滤波电容漏电等。出现这些问题时，应及时更换有问题的电容和二极管等元器件。此外，不可忽视触发电流故障，例如在触发电路中出现漏电流或电流值低于额定电流的情况，此时需先检查触发电路。
有利于可控硅参数设定
在开关电路中使用可控硅时，还需确保直流输出波形三相对称。如果发现直流输出波动且三相不对称，可以通过调整触发器脉冲相位来实现对称。此外，选择电路的续流管时，应遵循管压降越小越好的原则，理想状态下不应超过 0.5V。同时，要确保触发极的引线完好，以避免因截断导致脉冲丢失。
以上就是在开关电路中降低可控硅故障率的方法。此外，还应选择和应用品质优良的可控硅，建议在中国IC网等行业网站上进行选择，以保障购买的可控硅品质达到预期。
Maintaining Power Supply and Switch Stability
When using silicon controlled rectifiers (SCRs) in switching circuits, the first consideration is the stability of the power supply and switch. Regarding the power supply, it is essential to avoid unstable AC power supply, three-phase imbalance, phase loss, and single-phase issues, as well as to prevent surge situations, all of which can affect power stability. On the switch side, the main concern is poor contact, with common causes being damaged rectifier tubes. Therefore, it is crucial to promptly replace any faulty rectifier tubes.
Maintaining Circuit Current Stability
Many common SCR faults are caused by damaged or burned-out rectifier diodes. Other issues in the rectification section include breakdown of electrolytic capacitors, bridge rectifier failure, and leakage in filter capacitors. When these problems arise, it is important to replace the faulty capacitors and diodes promptly. Additionally, trigger current faults should not be overlooked; for instance, if there is leakage current in the trigger circuit or if the current value is below the rated current, the trigger circuit should be checked first.
Favorable SCR Parameter Settings
When using SCRs in switching circuits, it is also necessary to ensure that the DC output waveform is three-phase symmetric. If there are fluctuations in the DC output indicating three-phase asymmetry, this can be corrected by adjusting the phase of the trigger pulse. Furthermore, when selecting the freewheeling diode for the circuit, the principle of minimizing the voltage drop across the diode should be followed, ideally not exceeding 0.5V. It is also important to ensure that the leads of the trigger terminal are intact to avoid pulse loss due to cutoff.
The above points outline how to reduce the failure rate of SCRs in switching circuits. Additionally, it is advisable to choose and use high-quality SCRs, and it is recommended to select them from industry websites such as China IC Network to ensure the quality of the purchased SCRs meets expectations.
可控硅故障率的降低的方法(Methods to Reduce SCR Failure Rate)