T.L.E 90

"BASIC ELECTRONICS"

HALF-WAVE RECTIFIER

PARTS AND MATERIALS

• Low-voltage AC power supply (6 volt output)
• 6 volt battery
• One 1N4001 rectifying diode (Radio Shack catalog # 276-1101)
• Small "hobby" motor, permanent-magnet type (Radio Shack catalog # 273-223 or equivalent)
• Audio detector with headphones
• 0.1 µF capacitor (Radio Shack catalog # 272-135 or equivalent)

The diode need not be an exact model 1N4001. Any of the "1N400X" series of rectifying diodes are suitable for the task, and they are quite easy to obtain.

See the AC experiments chapter for detailed instructions on building the "audio detector" listed here. If you haven't built one already, you're missing a simple and valuable tool for experimentation.

A 0.1 µF capacitor is specified for "coupling" the audio detector to the circuit, so that only AC reaches the detector circuit. This capacitor's value is not critical. I've used capacitors ranging from 0.27 µF to 0.015 µF with success. Lower capacitor values attenuate low-frequency signals to a greater degree, resulting in less sound intensity from the headphones, so use a greater-value capacitor value if you experience difficulty hearing the tone(s).

LEARNING OBJECTIVES

• Function of a diode as a rectifier
• Permanent-magnet motor operation on AC versus DC power
• Measuring "ripple" voltage with a voltmeter

SCHEMATIC DIAGRAM

ILLUSTRATION