FIELD OF THE INVENTION
The present invention relates to a solar photovoltaic powered automatic electrical
device for churning dairy products. More particularly, the invention relates to a
stand-alone solar photovoltaic energy conversion system with electric motor
drive adaptable in the process of butter extraction
BACKGROUND OF THE INVENTION
Butter is a major ingredient in several food items in India and many other
countries. Majority of the population in India belongs to farming community and
each house in the communities possess several cattle such as cows, goats etc.
Traditionally, butter is extracted by churning dairy products, such as fresh cream,
fermented milk or cream and this method is prevalent in all the villages in India.
A churning stick is used to stir the fermented milk or cream inside a vessel
manually either using ropes or simply with hands. The instruments used in this
process are/ a fixed pot, wooden churner rod and ropes. The churner stick is
cylindrical in shape with its bottom provided with wooden stirring head. Two
ropes are used to fix the churning stick to an immovable means on either ends of
the stick and another moving rope is wrapped around the stick in between the
ends to rotate the stick back and forth. The fermented milk or cream is poured
into the fixed pot and the stirring head is made agitate the fermented milk or
cream by pulling the moving rope in back and forth motion by hands. After

continuous churning of about 20 to 30 minutes, butter gets separated and float
in the buttermilk. This process is a routine work in all the village households of
farming communities. This process of collected the fermented milk and cream,
churning them in a pot and extracting butter is generally carried out by women
in the village households.
Due to the advent of electric motors, the process of butter extraction from the
fermented milk and cream, is mechanized and is being used in dairy industries
where production of huge quantity of butter is involved. In the households of
economically developed regions electrical mixers are used to extract small
quantity of butter.
Most of the under developed regions are not having access to electric power or
suffering from long electric power outages or have limited access to electric
power. Especially for regions lying in high terrains, electric power access is a
costly affair as electric power transmission to these areas involves high erection
and commissioning cost of electrical equipments.
Recently solar photovoltaic conversion is attaining wide popularity due to its
stand-alone nature and green energy production. In solar photovoltaic
conversion the light energy from sun radiation is converted into electrical energy
and used to drive electrical power devices. Solar photovoltaic conversion avoids
emission of carbon monoxides, nitrogen oxides, sulphur oxides etc., as in the
case of a normal thermal power generating plant. The households need not pay
their utility bills in case of using solar photovoltaic energy conversion as the sun
radiation is a free and renewable resource.

In the past, apparatus pertaining to extraction of butter from milk, fresh cream,
fermented milk and fermented cream are invented by, William Hamilton as
disclosed in US patent 1935/ 2023056 and by C.L Mitchel etal., as disclosed in
US patent 1937/2200513. The cited inventions explain different methods of
butter extractions using mechanical rotary systems. Other inventions made by
Gladys Williams as disclosed in US patent 1933/1900626; by R.P.Robichaux
etal., as disclosed in US patent 1963/3109740 and by R.H.CIark and J.J. Terrell,
in US patent 1995/5463936, the rotary system of the butter extracting apparatus
is coupled with an electric motor powered by utility means, but they are still
dependent on grid power.
But in case of the villages and regions not having access to electric power or
suffering from long electric power outages or have limited access to electric
power these inventions are not suitable
Therefore there is a need for stand-alone solar photovoltaic energy conversion
system with electric motor drive in the process of butter extraction. This stand-
alone butter extraction system will also lead to women empowerment in villages
of India.
OBJECTS OF THE INVENTION
It is therefore an object of the invention to propose a stand-alone solar
photovoltaic energy conversion system with electric motor drive adaptable in the
process of butter extraction.

Another object of the invention is to propose a stand-alone solar photovoltaic
energy conversion system with electric motor drive adaptable in the process of
butter extraction in which an integratable electrical coupling means is provided
between the current source from solar photovoltaic cells and electric motor for
reliable and safe operations.
Yet another object of the invention is to propose a stand-alone solar photovoltaic
energy conversion system with electric motor drive adaptable in the process of
butter extraction, wherein a timing circuit for operating the electric motor drive
in back and forth motion is provided so as to obtain good quality of butter.
SUMMARY OF THE INVENTION
Accordingly, there is provided a solar photovoltaic power conversion system with
an electrical motor to extract butter by churning fermented milk or cream
contained in a vessel. The sun radiation is converted into electrical power by a
photovoltaic module and thus generated electrical power at the terminals of the
photovoltaic module, provides the voltage needed to drive a direct electric motor
through a control circuitry. The electric motor is coupled with a butter churning
rod to churn fermented milk or cream inside a vessel mounted on a butter
churning setup. The control circuitry is made up of cyclic timer to reverse the
positive and negative polarity of the voltage applied to the electric motor and

thereby making the butter churn rod to rotate back and forth. The churning rod
with stir head agitates the fermented milk or cream to extract butter from it. The
butter extraction implement with a simple configuration enables utilization
photovoltaic energy, which is free, in an apt way. The implement has got very
few components and mechanical variants which increases reliability and long life
of the implement.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1 shows the general layout of the solar powered butter churning method,
Figure 2 shows the butter churning implement in open condition.
Figure 3 shows the butter churning implement with churning rod inserted in the
vessel.
Figure 4 shows the top view of the vessel fixing stand
Figure 5 shows the top view of the motor fixing stand
Figure 6 shows the electrical circuit diagram of the entire system.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE
INVENTION
Figure 1 shows a general layout of the solar powered electric motor drive for
butter extraction method. The solar photovoltaic module [1] is made up of mono
crystalline solar cells connected in series to deliver direct current. There are two
terminals in the solar photovoltaic module; one is to take positive voltage out

and the other is to take out the corresponding negative voltage. The electric
motor [2] is designated to run at a constant speed when a constant direct
current (DC) voltage is applied at its two terminals. When the polarity of the
voltage at its terminals is interchanged, then the motor will reverse its direction
of rotation. This enables the electric motor to drive in back and forth motion as
required for butter churning rod [3]. The time duration for back and forth
motions are provided by a mechanical timer switch means [4]. The timer switch
reverses the polarity of the applied voltage to motor at constant intervals. The
output from the timer switch [4] for forward motion is taken to the electric motor
[2] through an electromagnetic relay means Rl [5] and through electromagnetic
relay means R2 [6] for reverse motion of the electric motor [2].
Figure 2 shows a butter churning implement in churn retracted condition. The
electric motor [2] is fixed on a rigid motor fixing base [7] through mechanical
means. The rigid motor fixing base is made to move up and down in mounting
rods [8] for operational ease through hollow sleeves [9]. The mounting rods are
made up of stainless steel metal and the hollow sleeves [9] are made with two
hollow cylinders placed co-axially. The outer ring of the sleeve is made up of
stainless steel metal and the inner ring is made of brass metal to enable friction
free motion in the mounting rods [8]. The entire set-up is mounted on a rigid
metal base [10]. The vessel [11] for churning the fermented milk is kept at the
centre of the base [10]. The motor shaft end is coupled to the butter churn rod
through a mechanical screw means [12] to ensure firm coupling and to avoid
eccentric operation of the churn rod [3]. A chum head contains stir blades [13]
to agitate the fluid in back and forth motion inside the vessel.

Figure 3 shows the butter churning implement with churning rod [3] inserted into
the vessel [11]. The motor fixing base [7] was made to slide down and firmly
fixed using threaded screw means [14]. There is fool proof mechanism to avoid
any sudden sliding of the motor fixing base [7] causing the churn head [13] to
hit the vessel [11] bottom. There is step [15] in the mounting rods to hold the
motor fixing base and it will not slide beyond the step. The step is formed by
increasing the diameter of mounting rod beyond this step.
Figure 4 shows the top view mounting setup base plate [10] and figure 5shows
the top view of motor fixing base plate [7].
Figure 6 shows the electrical wiring diagram of the implement. The terminals of
the solar photovoltaic module [1] are connected to a double pole single throw
switch means [16]. There is a diode connected in anti-parallel to the polarity of
solar photovoltaic module to avoid damage of solar photovoltaic module due to
reversal of power from load. The timer switch [4] has got two contact points,
one contact, CI is for forward rotation polarity and the other contact C2 is for
reverse rotation polarity. The contact CI is connected to an electromechanical
relay [5] for forward rotation operation and contact C2 is connected to an
electromechanical relay [6] for reverse rotation operation. The forward and
reverse operation of the electric motor [2] is achieved by the cyclic operation of
the timer switch [4]. The auxiliary power requirement of the timer switch [4],
electromechanical relays [5], [6] are met by the power generated by solar
photovoltaic module itself and hence it does not require any storage battery or
auxiliary power supply from utility or other resources. A protection switch is
placed in between the power circuit and electric motor [2] to avoid any high

current damaging the electric motor due any short circuit or mal-operation of the
circuit. The circuit developed does not involve any complex devices,
programmable controllers, computer programs etc., and thereby ensuring
reliability of the entire implement.
Figure 7 shows the cyclic timing operation of the timer switch. The dark areas
indicate ON condition of the particular switch. Sum of the turn ON time of
contact, CI and the turn ON time of contact, C2 constitutes one cycle time. And
the cycle is repeated till the extraction of butter is accomplished. It can be noted
the duration of the rotation of electric motor can be increased or decreased by
suitably adjusting the cycle operation of the timer.

WE CLAIM:
1. A solar photovoltaic powered automatic electrical device for churning dairy
products, comprising: a solar photovoltaic module, a cyclic timer switch means,
two electromagnetic relays located on an adjustable base, an electric motor and
a vessel with a churning rod having a stir head mounted on a mechanical
support, wherein the photovoltaic module converting solar radiation to generate
electrical power at the terminals of the photovoltaic module which drives a direct
electric motor through a control circuitry, the electric motor is coupled to the
churning rod through a coupling to churn fermented milk or cream disposed
inside the vessel, wherein the control circuitry is made up of a cyclic timer to
reverse the positive and negative polarity of the voltage applied to the electric
motor and causing the churning rod to rotate back and forth and wherein the
churning rod with the stir head agitates the fermented milk or cream to extract
butter from the milk or cream.
2. The device as claimed in claim 1, wherein the adjustable motor base is supported
by a set of mounting rods.
3. The system as claimed in claim 1 or 2, wherein the mounting rods are
provided with a set of bimetallic sleeves for smooth movement.

4. The device as claimed in claim 1, wherein the coupling between the electric
motor and churning rod is provided to avoid eccentric operation.
5. The device as claimed in claim 1, wherein the photovoltaic module comprises
a plurality of photovoltaic cell.
6 The device as claimed in claim 1, comprising a cyclic timer switch (4) and
electromagnetic relays (5, 6) powered by solar generated power to reverse
the polarity of the applied voltage to the electric motor, and reverse the
rotational direction of the motor.