Regulated Linear Power Supply Dual-Output Adjustable Linear Regulated Power Supply Block Diagram Simple Description • Transformer: “Downconvert” the AC line voltage to a smaller peak.
Download ReportTranscript Regulated Linear Power Supply Dual-Output Adjustable Linear Regulated Power Supply Block Diagram Simple Description • Transformer: “Downconvert” the AC line voltage to a smaller peak.
Regulated Linear Power Supply Dual-Output Adjustable Linear Regulated Power Supply Block Diagram Simple Description • Transformer: “Downconvert” the AC line voltage to a smaller peak voltage Vm, usually about 2-3 Volts larger than the ultimately desired DC output. • Diode Rectifier Circuit: produce a waveform with large DC component. • Filter: smooth out the rectified sinusoid. • Regulator: eliminate residual ripple Half-Wave Rectifier Tin Cause of ripple: the capacitor is discharged for almost an entire period. inversion Ripple Reduction: Do not allow the capacitor to discharge so frequently An Inverting Half-Wave Rectifier If Vin >0, D1 and D2 are off. If Vin <0, D1 and D2 are on and Vout>0. An Non-Inverting Half-Wave Rectifier If Vin >0, D1 and D2 are on, Vout>0. If Vin <0, D1 and D2 are off. Full-Wave Rectifier Inverting Non-Inverting Full-Wave Rectifier Alternative Drawing Inverting Full-Wave A.K.A. Bridge Rectifier Non-Inverting Using Constant Voltage Diode Model Vout=-Vin-2VD, on Vout=Vin-2VD, on Input versus Output |Vin|<2VD,on Addition of the Smoothing Capacitor Modification of Ripple Estimation Formula Modification: 1. Turn-on voltage 2. 1/2 to account for inversion of negative peaks. Maximum Reverse Voltage VB=VD,on VA=VP Vp is the amplitude of Vin VAB=VP-VD,on Maximum reverse voltage is approximately Vp Compare Maximum Reverse Bias Voltage to Half-Wave Rectifier A reverse diode voltage must sustain larger reverse bias voltage Currents as a function of time Application of Bridge Rectifier Summary A Voltage Regulator Circuit Schematic Full-Wave Rectifier Alternative Drawing Inverting Full-Wave A.K.A. Bridge Rectifier Non-Inverting Rectified Waveform Smoothing Capacitor LM317/LM337 Without Load Resistance (CL=100 uF) 9.36 V and -9.36 V Load Assumption • Assume that the load draws 0.2 A of current • Load resistance: 9.36V/0.2A=36.5 Ohms Each capacitor is 100 Resistor is 37.5 Ohms Use Reload update curves Increase capacitor from 100 uF to 470 uF. Reduced ripples Extra Slides I-V Characteristic of LED