Production of digital adjustable voltage-stabilized power supply circuit

　　The picture below is a digital adjustable voltage-stabilized power supply circuit composed of CD4017, CD4066, and CD4060 . The principle is relatively simple, so I won’t go into details here. To obtain the corresponding voltage value, the values ​​of R1…R6 must be debugged . The values ​​shown in the figure are for reference only. There will be differences due to the certain discreteness in parameters of components of the same type, as well as the on-resistance of 4066, etc., so debugging is required.

　　debug:

　　The circuit can be debugged after the assembly and soldering inspection is correct. R1…R6 are not loaded before debugging. Use a 100 ohm resistor and a 10K potentiometer in series, connect it to the position of the R1 resistor, energize it and adjust the output end to the required voltage of 1.5V. After 5V, disconnect the power supply and remove them to measure their resistance values, and then use a fixed Replace the resistor, and then connect it to the position of R2...In this way, adjust R2...R6 in sequence. In this way , the debugging is completed. If the resistance value is not exactly the nominal resistance value, it can be obtained by connecting in series and parallel. Speed ​​adjustment 47K resistor or 1U capacitor adjusts the key scanning speed.

　　Extended applications:

　　If you want to increase the output voltage, the maximum value shown in the picture is about 19V. If you want to go higher, you can also increase the output voltage of the power supply transformer to increase the output voltage, but the input terminal of 317 should be less than 45V, that is, the maximum effective output value of the transformer is 30V, the maximum output voltage at the output terminal is 36V. There are also some pins of 4017 and 4066 that are not used, and two more voltage values ​​can be added. You can also use a potentiometer to replace one of the resistors, and it becomes a regulated power supply that can be adjusted at will.