THE POWER SUPPLY SECTION OF RECLC

• Rechargeable and electronic controlled lights

  KENNETH L. AYSON
• Power supply section


  Provides the necessary electric source for the LED to turn on and for the battery to recharge. Battery is included in this section.
• Types of power supply

  • Converter power supply
  • Inverter power supply
  • Transformer-less power supply
• Inverter power supply


  Converts small amount of DC into AC
• Devices using inverter power supply

  • Buses that have televisions and audio system
• Converter power supply


  Converts AC into small amount of DC
• Devices using converter power supply

  • Television
  • Radio receivers
  • Battery chargers
  • RECLC
• AC input stage


  Connects the RECLC to the main AC source. Composed of: AC plug, fuse, switch
• Transformer stage


  Reduces/decreases the 220ACV into smaller amount of ACV. Composed of step-down transformer.
• Transformer


  Has two parts of windings: primary winding and secondary winding
• Primary winding


  Receives the 220ACV, connected to AC input stage
• Secondary winding


  Produces the reduced amount of ACV, connected to rectifier stage
• Types of step-down transformers

  • Single winding
  • Center-tapped
  • Multi-tapped
  • Multiple winding
• Rectifier stage


  Converts the AC into pulsating DC. Composed of rectifier diodes.
• Rectifier diode


  Semiconductor device that allows the flow of electricity in one direction only
• Rectifier diode specifications


  • 1N4001 (50V, 1A)
  • 1N4002 (100V, 1A)
  • 1N4003 (200V, 1A)
  • 1N4004 (400V, 1A)
  • 1N4005 (600V, 1A)
  • 1N5400 (50V, 3A)
  • 1N5401 (100V, 3A)
  • 1N5402 (200V, 3A)
  • 1N5403 (300V, 3A)

  
• Rectifier diode operation


  Allows the flow of current in one direction only
• Current enters the anode

  Only the positive side of AC is allowed to enter
• Current enters the cathode

  Only the negative side of AC is allowed to enter
• Types of rectifier circuits

  • Half-wave rectifier
  • Full-wave rectifier

  
• Types of full-wave rectifier

  • Full-wave center-tapped rectifier
  • Bridge-type full-wave rectifier
• Filter stage


  Smoothens the pulsating DC from the rectifier stage into semi-pure DC
• Pulsating DC


  DC voltage with AC component (ripple), dangerous to electronic devices
• Pure DC


  Voltage without ripple, like from batteries
• Semi-pure DC


  Voltage where the ripple is removed using filter circuit
• Filter stage components


  • Electrolytic capacitor
  • Epoxy-type capacitor
  • Inductors
  • Resistors
• Single filter capacitor circuit


  Simplest filter, uses one electrolytic or epoxy-type capacitor connected in parallel to rectifier stage output
• Resistor-capacitor filter circuit


  Uses network of resistor and capacitor, starts with filter capacitor, then resistor in series, then another filter capacitor
• Inductor-capacitor filter circuit


  Uses network of inductor and capacitor, starts with filter capacitor, then inductor in series, then another filter capacitor
• Single Filter Capacitor Circuit

  Use one to two capacitors with same specifications connected in parallel
• Resistor-Capacitor Filter Circuit


  Starts with filter capacitor, then resistor in series, then another filter capacitor
• Inductor-Capacitor Filter Circuit


  Starts with filter capacitor, then inductor in series, then another filter capacitor
• Choosing the electrolytic capacitor

  • Capacitance value: Higher is smoother and more effective DC voltage output, choose 1000 µF to 6800 µF
  • Voltage rating: Should be 3V higher than secondary winding voltage of step-down transformer
• Capacitor values for different transformer voltages

  • 6.3V: 1000 µF, 4700 µF
  • 10V: 3300 µF, 4700 µF, 10000 µF
  • 16V: 1000 µF, 2200 µF, 3300 µF, 3000 µF, 4700 µF
  • 25V: 1000 µF, 2200 µF, 3300 µF, 4700 µF, 6800 µF
  • 35V: 1000 µF, 2200 µF, 3300 µF, 4700 µF
  • 50V: 1000 µF, 2200 µF, 4700 µF
  • 63V: 1000 µF, 2200 µF, 3300 µF, 4700 µF
• Regulator Stage


  The stage that stabilizes and maintains a constant output voltage of the power supply circuit
• Constant DC Voltage


  Consistent voltage output despite changes in previous stages
• How regulator stage works


  • Maintains a specific voltage output despite changes in previous stages
• If voltage at AC Input Stage decreases

  All voltages throughout power supply section also decrease
• Types of regulator circuits

  • Resistor
  • Zener Diode
  • Transistor
  • Integrated Circuit
• Simple Resistor Regulator


  Uses one resistor connected in parallel with filter capacitor, also called a bleeder resistor