Converting Alternating Current To Direct Current; Half Wave Rectifier Single Diode - Tecumseh ECV100-120 - TECHNICIAN S Handbook

CONVERTING ALTERNATING CURRENT TO
DIRECT CURRENT
In order to charge a battery, it is necessary to convert
alternating current (A.C.) to direct current (D.C.). This is
accomplished by using a diode or rectifier (diag. 3). A
single diode makes use of only one half of the A.C. signal
and is known as HALF WAVE RECTIFICATION (diag. 4).
This is acceptable in certain applications. In certain
situations it is necessary to make use of the entire A.C.
signal. To accomplish this, multiple diodes in a bridge
configuration are used to produce FULL WAVE
RECTIFICATION (diag. 5).
Current flows through a diode when the anode is more positive than the cathode. The cathode end of the diode should
point toward the battery when diode is used between a charging system and a battery.

HALF WAVE RECTIFIER SINGLE DIODE

The single diode allows only the positive half of the A.C. signal through. It does not allow the negative portion through.
FULL WAVE RECTIFIER (BRIDGE
RECTIFIER)
The full wave rectifier makes use of the entire A.C. signal,
converting it to D.C.
COMPONENTS
BATTERY
The batteries used in conjunction with Tecumseh engines
are 12 volt lead acid or "maintenance free" style. The
chemical energy produced by the dissimilar metals of the
battery plates provides a electrical potential that is used
to power the electric starter or unit accessories. Consult
the original equipment manufacturer's service manual for
battery size, capacities, and testing procedure.
WIRING
The wires used in Tecumseh electrical systems are copper stranded with an insulated coating around the copper
strands.
CONDITION: All wiring must be fully insulated between connection points, securely fastened and free of foreign
material (such as rust and corrosion) at the connection points. This is especially important in the use of batteries
where much of the potential may be lost due to loose connections or corrosion. Remember to check the insulation on
the wire. All it takes is a pin hole to "ground out" on the engine or frame. This is of special concern when moisture or
water is present. This may cause the engine to run erratically or be impossible to start.
FULL WAVE RECTIFIER
(BRIDGE RECTIFIER)
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