Design of Adjustable DC Stabilized Power Supply Circuit Module
Working principle of the circuit: After adding 220V AC voltage to the primary side W1 through the transformer T, the circuit obtains 35V and 6V AC voltages on the secondary side W2 and W3 respectively, and the secondary side W2 terminal is rectified by diodes VD1~VD4, capacitors After filtering by C1 and C2, it is input to the input terminal of the three-terminal integrated voltage stabilizing circuit of IC, and a DC voltage of 35V is output through the IC voltage stabilizing integrated circuit, resistor R1 and capacitor C4. The 6V AC voltage output by the W3 coil on the secondary side outputs a -1.25V negative voltage as an auxiliary power supply through the diode VD5, capacitor C3, resistor R2 and Zener diode VS. The rheostat RP is added to the control terminal of the IC integrated circuit. By adjusting the rheostat RP, the output terminal can output a DC power supply of 0~30V. IC uses LM317 three-terminal voltage regulator integrated circuit; R1 and R use 1/2W metal film resistors; C1 and C3 use aluminum electrolytic capacitors with withstand voltages of 50V and 10V respectively; C2 and C4 use CD11-16V electrolytic capacitors; VD1 ~VD5 chooses IN4007 silicon rectifier diode; VS chooses IN4106 or 2CW60 silicon voltage regulator diode; RP can use WSW type organic solid fine-tuning variable resistor; T chooses 10W power transformer with secondary side voltage of 35V and 6V.
Design of Numerical Control DC Stabilized Power Supply Circuit
The digitally controlled DC stabilized power supply circuit introduced in this example uses control buttons and digital integrated circuits, and uses LED light-emitting diodes to indicate the output voltage value. The output voltage is 3-+15V, a total of 8 adjustable levels. The maximum output current is 5A. The NC hundred-current regulated power supply circuit is composed of +l2V regulated voltage circuit, voltage control/display circuit and regulated voltage output circuit.
Circuit principle: +l2V stabilized voltage circuit is composed of power transformer T, rectifier bridge stack uR, filter capacitors Cl, c2, c6, c7 and three-terminal voltage stabilized integrated circuit ICl. The voltage control/display circuit consists of control button S1, reset button S2, resistors RO-Rll, potentiometer RP, capacitors C3-C5, Schmitt trigger integrated circuit IC2, decimal counting/pulse distributor integrated circuit IC3, Electronic switch integrated circuits IC4, 1C5 and light-emitting diodes VLl-VL8 composition. The voltage regulator output circuit is composed of three-terminal adjustable voltage regulator integrated circuit IC6, resistor Rl2 and capacitors C6-C9. When SO is connected, the AC 220V voltage is stepped down by T, rectified by UR and filtered by C6 and C7, one way is used as the input voltage of lC6; the other way is stabilized by ICl to +l2V, which is used as the working power supply of IC2-IC5. After lC3 is powered on and reset, its YO terminal outputs high level (YI-Y8 terminal outputs low level), so that the electronic switch SO1 inside IC4 is turned on, and R4 is connected to the voltage stabilizing circuit. At this time, the output voltage is +3V, At the same time VLl lights up. After pressing S1, the pulse signal generated by the oscillator composed of IC2 and peripheral resistance-capacitance components is added to pin 14 (CP terminal) of IC3 through S1, as the counting pulse of IC3, and the Y1 terminal of IC3 outputs a high level ( YO terminal becomes low level), S02 is connected, R5 is connected to the voltage regulator circuit, the output voltage at this time is +4·5V, and VL1 is lit at the same time. When 51 is pressed continuously, the YO-Y8 terminals of IC3 will output high levels in turn, so that S01-S08 will be turned on in turn, resistors M-Rll will be connected to the voltage stabilizing circuit in turn, and IC6 will output from low to high in turn. (+3V, +4·5V, +5V, +6V, +7·5V, +9V, +l2V, +l5V) 8 voltages. VLl-VL8 light up in turn. In any gear other than +3V, just press S2 once, IC2 will be cleared and reset, and return to the lowest voltage gear of +3V.
Component selection
Rl-Rl2 selects 1/4W metal film resistor or carbon film resistor for use. RP selects organic solid variable resistors for use. Both Cl and C8 use aluminum electrolytic capacitors whose withstand voltage is 16V; C2-C6 and C9 use monolithic capacitors; C7 selects aluminum electrolytic capacitors whose withstand voltage is 25V. VLl-VL8 selects the light-emitting diode of φ3mm for use. UR uses 2A. 5OV rectifier bridge stack. ICl selects LM7812 or CW7812 three-terminal voltage regulator integrated circuit; IC2 selects CD4093 Schmitt trigger integrated circuit; IC3 selects CD4017 or MCl4107 decimal counting/n permanent charge distributor integrated circuit; IC4 and 1C5 both select CD4066 electronic Switch integrated circuit; IC6 selects LM317 three-terminal adjustable voltage regulator integrated circuit for use. S0 selects a power switch with 250V and a contact current load of 5A; S1 and S2 select miniature moving and closing buttons.
