76Amp Hour of 24V
rechargeable lead-acid battery pack. Made up from 4 12V
batteries secured in the chassis. Their mass contributes to
low center of gravity.
DC 24V 150Amp
reversing battery motor controller on an Aluminium heatsink. The motor controller is the
heart of the electrical drive system and delivers
the variable 0 to 24V reversible polarity power
supply to the drive DC electric motors.
2 x 36V 1000W electric motors running at 24V to deliver
complete drawing set for the Yard Tractor is available
from our Plans Order page
Not Shown - Instrument panel
with ignition switch, battery meter and reverse switch
See the detailed drawing
for the circuit diagram.
principal elements of the electrical drive system are the DC
battery motor controller, the DC electric motors and the
rechargeable lead-acid batteries. In addition the motor speed
controller requires low power speed "demand" signals (from the
potentiometer). There is also an on/off switch, a reverse switch and optionally
a battery condition monitor to let you see the stage of charge
of the batteries. The DC battery motor controller is at the heart of
the system - it takes the fixed nominal 24V from the battery pack
and outputs a variable 0 to 24V to the motors. This
delivers the tractor's variable speed. By reversing the polarity to the electric motor the
speed controller also provides the reverse drive. The
motor controller suggested in the plans can be substituted by
other similar current rated DC battery motor controllers - you
The 24V 660W DC electric motors are commonly
available and are easily mounted and
connected to the drive transmission by roller chain.
Standard sized rechargeable lead
acid batteries are used. These are manufactured by a large range
of suppliers and can provide several hundred charge cycles
during their lifetime. You'll also need a good multi-mode
battery charger to keep the batteries in good condition.