7
LTC1042
1042fa
APPLICATIO S I FOR ATIO
WUUU
Wind Powered Battery Charger
A simple wind powered battery charger can be
constructed using the new LTC1042, a 12V DC permanent
magnet motor, and low cost power FET transistor.
The DC motor is used as a generator with the voltage
output being proportional to its RPM. The LTC1042
monitors the voltage output and provides the following
control functions:
1) If generator voltage output is below 13.8V, the control
circuit is active and the NiCad battery is charging
through the LM334 current source. The lead acid
battery is not being charged.
2) If the generator voltage output is between 13.8V and
15.1V, the 12V lead acid battery is being charged at
about a 1A/hour rate (limited by the power FET).
3) If generator voltage exceeds 15.1V (a
condition caused
by excessive wind speed or 12V battery being fully
charged) then a fixed load is connected thus limiting
the generator RPM to prevent damage.
This charger can be used as a remote source of power
where wind energy is plentiful, such as on sailboats or
remote radio repeater sites. Unlike solar powered panels,
this system will function in bad weather and at night.
LTC1042 • A105
8
7
6
5
1
2
3
4
LTC1042
12V
GENERATOR
WIND
LM334
4.5V
NiCAD
BATTERY
215k
10k
0.1µF
MTP8N05
36Ω
5W
1N4001
MTP8N05
12V
LEAD ACID
0.1µF
0.1µF
107k
10M
WITHIN
WINDOW
13.8V TO 15.1V
OVER VOLTAGE
(>15.1V)
100k
10k
68Ω
LT1004-1.2
+
+
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
