Linear Regulated Power Supplies, Switching Power Supplies and Phase Controlled Power Supplies in Detail
DC power supply according to the different conversion methods, can be divided into three categories of linear regulated power supply, switching power supply and phase-controlled power supply.
1, linear regulated power supply to meet the electronic circuit needs of DC voltage requirements and power quality (precision, ripple, etc.) requirements, but there are two major drawbacks: First, the adjustment tube VT work in the linear amplification state, loss is very large, the power supply efficiency is very low; the second is the need to use a frequency transformer T, so that the entire power supply volume, heavy weight.
2, switching power supply is to overcome the shortcomings of the linear regulated power supply and appeared, because of its power (power) electronics is always working in the switching state and named.
3, phase-controlled power supply is the thyristor phase control power supply. The same as switching power supply, phase-controlled power supply in the power electronics is also working in the switching state, only its operating frequency is the frequency (50Hz), rather than high frequency. In contrast, a significant advantage of phase-controlled power supply is the simplicity of the circuit and the convenience of control. Its main disadvantage is also to have an industrial frequency transformer, so that the whole power supply is large and heavy. In addition, phase-controlled power supply DC output voltage ripple frequency is only a few times the frequency (single-phase full-bridge control for 2 times, three-phase full-bridge control for 6 times), the need for larger filters to have a better filtering effect. The switching power supply DC output voltage ripple frequency is very high, often above 20kHz, so only a very small filter can be. Due to the low switching frequency of the phase-controlled power supply, its response to the control is also slower than the switching power supply.
In accordance with the custom, switching power supply refers to power (power) electronic devices operating in the high-frequency switching state of the DC power supply, so also known as high-frequency switching power supply, and phase-controlled power supply is not included in the switching power supply.
