Secondary sensing system for contactor control system

In an animal confinement structure having a contactor control device which controls a temperature control apparatus utilized for applying heating or cooling to the structure responsive to the ambient temperature sensed, a secondary system employed for control of temperature outside a preselected temperature regime, upon the failure of the contactor control device or loss of power. A remote temperature sensor is operatively connected to a pair of electronic thermostatic circuits for independently sensing the ambient temperature for comparison to the preselected range, and connected to a power supply utilized for energizing a relay resulting in the temperature control apparatus by independently actuated responsive to the sensed ambient temperature. The secondary system may be selectively used to control a temperature control apparatus which provides either heating or cooling.

FIELD OF THE INVENTION 
The present invention relates to animal husbandry and more specifically to 
electronic circuitry for maintaining the internal ambient temperature in 
an animal confinement facility within some preselected range. In even 
greater particularity the present invention relates to electronic 
circuitry used in conjunction with a temperature control apparatus which 
is mutually controlled by a contactor control device in a power supply 
circuit and circuitry which can be operatively connected to the contactor 
control system. This secondary system will be employed for control of the 
temperature control apparatus outside a preselected temperature regime, 
upon the failure of said contactor control device or loss of power. 
BACKGROUND OF THE INVENTION 
Modern animal confinement facilities have to include several units which 
all cooperate together within the structure itself for maintaining the 
internal ambient temperature within some preselected range. Typically, the 
systems utilized for controlling the temperature within an animal 
confinement structure include; fans, heaters, controllers, curtain 
operators, alarms, curtain drops, evaporative cooling systems and 
contactor control systems. The contactor control devices utilized in these 
systems must insure adequate selective control as to whether heating or 
cooling will be applied to the animal confinement structure responsive to 
the internal ambient temperature being sensed in order to maintain this 
temperature within the preselected range. The contactor control systems 
which are utilized have not been able to adequately control for small 
fluctuations in temperatures. Fluctuations of more than 1 degree from the 
ideal can result in disaster with some forms of livestock, in that these 
small, temperature fluctuations have been associated with some of the 
livestock becoming sick, or in some cases, even dying. While most systems 
used in typical temperature control systems can usually prevent death, 
their inability to provide adequate control within some preselected range 
does very little in preventing stress or sickness to various forms of 
livestock. These systems do not provide for the adequate control to 
properly actuate the temperature control apparatus when the sensed ambient 
temperature is outside the preselected range. 
SUMMARY OF THE INVENTION 
It is the principal object of the present invention to provide an improved 
apparatus for controlling the internal ambient temperature beyond the 
control means provided by stated contactor control device so that it is 
being maintained within some preselected range of temperature. This 
improved apparatus utilizes circuitry which allows for initially sensing 
the ambient temperature independently of the contactor control device in 
order to compare it to the preselected range, selection as to whether the 
apparatus utilized for controlling a device which is designed to apply 
heating or cooling to the structure in direct response to the sensed 
internal ambient temperature; and finally for actuating the device in 
response to this sensed temperature.

DESCRIPTION OF A PREFERRED EMBODIMENT 
Referring to the drawings for a clearer understanding of the invention, it 
will be noted in FIG. 1, that the confinement house 10 is equipped with a 
plurality of windows 11, curtains 12, doors 13, vents 14 and fans 16. The 
house 10 also includes heaters, sprayers and other devices, hereinafter 
commonly called temperature control apparatus (TCA) which are not 
illustrated, yet which may all be controlled from a single contactor 
control panel 17. The contactor control panel includes a plurality of 
circuits in a normally open or normally closed configuration, each circuit 
dedicated to a particular TCA. To insure the health of the animals, the 
present invention permits selected ones of these TCA's to be connected to 
a separate secondary sensing system, which will actuate that particular 
TCA in response to a sensed condition. 
As may be seen in FIG. 2, the major component in the contactor control 
system is a forty amp contactor relay 18 which is a normally open relay 
controlled by a primary control device such as a thermostat or electronic 
controller. The relay 18 is operatively connected in the circuit between a 
circuit breaker 19 and the TCA and assists in maintaining the temperature 
at the selected level. 
Also connected between selected ones of the TCA's and its circuit breaker 
is a secondary sensing system, which provides a failsafe or backup for the 
contactor control system. The secondary sensing system operates 
independently of the primary control device and serves to prevent 
disastrous results when the primary control system and the contactor 
control panel do not work properly. That is to say, the secondary sensing 
system senses gross deviations from the ideal temperature and actuates TCA 
to ameliorate the temperature extreme. In as much as the temperature is 
normally controlled to within .+-.1.degree. of a selected ideal 
temperature, this gross deviation may be .+-.10.degree. for example, and 
would only be reached if something untoward occurred in the primary 
system. 
To this end I use a temperature sensor 20 which is independent of the 
primary control system but which is associated with one of the TCA and 
located appropriately to sense the ambient temperature within the house. 
This temperature sensor is operatively connected to two parallel 
electronic thermostatic circuits 21a and 22b and which act in effect like 
switches in a power supply circuit 22 for the secondary sensing system. 
Normally, both of these sensors create an open circuit condition in a 12 
volt DC circuit which includes a coil 23 and a "heat" or "cool" selector 
switch 24. Selected switch 24 is merely means for connecting either 
electronic thermostat circuit 21a or 22b with the coil 23 and the power 
supply. These circuits 21a or 22b, which are commonly available, have a 
manually actuable control knob (not shown) to enable the operator to set a 
rotating slide switch to a selected threshold setting. Thus these 
electronic thermostat circuits 21a and 22a allow the operator to set an 
upper or lower temperature for the acceptable temperature range, thereby 
establishing the gross deviation permitted before the secondary sensing 
system actuates a particular TCA. 
For example, if the primary control system were maintaining a chicken house 
at 75.degree. F. and one secondary sensing circuit was connected to 
actuate a cooling fan, the electronic thermostatic circuit might be set at 
82.degree. F.; another device, such as a heater might be connected to 
another similar secondary sensing circuit which includes an electronic 
thermostatic circuit set at 60.degree. F. The secondary sensing circuit 
for the fan would have selector switch 24 set in the cool position while 
the secondary sensing circuit for the heater would have its selector 
switch 24 set to heat. Both circuits might be connected to provide backup 
to the same contactor control system. 
The actual backup is provided through a secondary relay 26 connected in 
parallel to the contactor relay 18 such that when the selected electronic 
thermostat circuit 21a or 22a senses an abnormal temperature coil 23 is 
actuated to move the common arm of the relay 26 to the normally open 
terminal to actuate the appropriate TCA. 
It will be appreciated that the contactor control system is actually a 
pre-wired single, double, or triple pole contactor system which may 
control up to twelve circuits, thus a built in backup for each or any 
circuit is envisioned within the scope of the invention. In the event of a 
power failure to the contactor panel the secondary sensor circuits for 
each TCA would be actuated, by the loss of power rather than temperature 
deviation, that is to say the normally closed connection would open, and 
assuming that the confinement house had an energy power generator or the 
like all TCA's connected to the secondary sensing system and alarms would 
be actuated. 
From the foregoing it may be seen that I have devised a system which 
conveniently and independently actuates each TCA responsive to an 
unexpected event, greatly reducing the likelihood of a disaster. 
While we have shown our invention in one form, it will be obvious to those 
skilled in the art that it is not so limited but is susceptible of various 
changes and modifications without departing from the spirit thereof.