采用晶闸管预调整的流稳压电源电路设计.docVIP

采用晶闸管预调整的直流稳压电源电路设计 采用晶闸管预调整的直流稳压电源电路设计 摘　　要 在电子线路的相关应用中，电源是比不可少的部分。直流稳压电源作为直流能量的提供者在各种电子设备中有着极其重要的地位。它的性能良好与否直接影响到电子产品的精度、稳定性和可靠性。 采用集成稳压器LM317构成的直流稳压电源，具有优异的性能、较高的可靠性，低廉的维修费用等优点。然而，作为功率器件，必须考虑到稳压器的热功耗。当稳压器输入电压固定，输出电压较小时，LM317压降则会较大。此时如果输出较大电流，将导致消耗在稳压器上的功率很大，可能温升过大，影响LM317正常工作。设计采用了晶闸管，实现对LM317输入电压的预调整，即输入电压以一定限度随着输出电压变化。电路通过检测稳压器两端电压差获取控制信号，通过晶闸管触发电路产生触发脉冲，控制晶闸管的导通角，从而实现控制稳压器输入输出的电压差在3V左右。最终，该设计降低了稳压器热功耗，延长了其使用寿命，提高直流稳压电源稳定性。 本电源输出电压从0～30V连续可调，最大输出电流可达1.5A。 关键词：触发脉冲；晶闸管；电压预调整；稳压器 The Circuit Design of Pre-adjusted DC Power Supply Using Thyristor ABSTRACT Related applications in the electronic circuit, the power supply than the essential part.DC-DC power supply as energy providers in a variety of electronic devices has an extremely important position.Its performance is good or not directly affect the accuracy of electronic products, stability and reliability. Including the integrated regulator LM317, the DC power supply has many advantages, like excellent performance, high reliability, low repair cost and so on. However, as the power device, the heat loss of the regulator must be considered. When the regulator input voltage is fixed and the output voltage is small, the voltage drop on the regulator will be large. If the output current is great at this time, it will lead to the consumption of the regulators power greatly. Excessive temperature rise may affect the LM317 work. This design based a thyristor to pre-adjust the input voltage from the LM317, so that the input voltage can varies with the output voltage at a limitation. Voltage regulator circuit by detecting the voltage difference across access control signal, generated by thyristor trigger circuit to trigger pulse to control thyristor conduction angle, implements the control of the input and output voltage regulator voltage difference about 3V. Eventually, this design reduces the heat loss and increases the useful life, so reaches i