How to start the design of adjustable voltage regulated power supply application

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How to start the design of adjustable voltage regulated power supply application [Copy link]

　The control chip of the DC regulated power supply adopts the relatively mature imported components, and the power components adopt the latest high-power devices developed internationally. The adjustable DC regulated power supply design eliminates the bulky volume of the traditional DC power supply due to the power frequency transformer. Compared with the traditional power supply, the high-frequency DC power supply has the advantages of small size, light weight, and high efficiency. At the same time, it also creates conditions for reducing the volume of high-power DC power supply. This power supply is also called high-frequency adjustable switching power supply. The adjustable DC regulated power supply has complete protection functions, the overvoltage and overcurrent points can be continuously set and predicted, and the output voltage can be controlled by a touch switch.

　　How it works

　　When the input AC voltage of the parameter voltage stabilizer is 150V-260V, the output voltage is stabilized at 220V, which is effective. Below and above this range, its efficiency will decrease. The first step of control is to use a single-chip microcomputer to adjust the input voltage below 310V and above 90V to 190V-250V, and then use the parameter voltage stabilizer for voltage stabilization, which is very effective.

　　The AC voltage input from the mains fluctuates greatly. After being filtered out by the overvoltage absorption filter circuit to remove interference voltages such as high-frequency pulses, it is sent to the DC switching power supply, AC sampling circuit and control execution circuit.

　　The DC switching power supply has low power, but can convert 60-320V AC voltage into +5V, +12V, -12V DC voltage. +5V voltage is used for single-chip microcomputer, and ±12V voltage is used for high-power switch module of control circuit.

　　The single-chip microcomputer analyzes and judges the input voltage data collected by the sampling circuit and sends a control signal to the trigger circuit to control and adjust the output voltage.

　　The control execution circuit is composed of an SSR zero-crossing switch high-power module and an autotransformer with a tap. An RC absorption circuit is used between the SSRs to absorb overvoltage and overcurrent, so that the SSR will not be damaged during switching. The control execution circuit controls the input voltage of 90-310V to the range of 190V-240V, and then sends it to the parameter regulator for precise voltage regulation.

　　The parameter voltage stabilizer is composed of an LC oscillator composed of an inductor and a capacitor, and the oscillation frequency is 50HZ. No matter how the mains power changes, its oscillation frequency will not change, so the output voltage will not change, and the voltage regulation accuracy is high. Even if the input voltage waveform is greatly distorted, it will be a standard sine wave after the oscillation output of the parameter voltage stabilizer, so the voltage stabilized power supply has strong anti-interference and purification capabilities.

　　Protection alarm circuit: When there is a situation that endangers the safety of the equipment, only sound and light alarms are issued to remind the operator to take measures without cutting off the output voltage. Sound and light alarms will be issued when there is no output voltage, the temperature of the control box is too high, the mains input is higher than 300V, and the mains input is lower than 130V. When the input current is too large, the input (output) air automatic switch will automatically trip.