Some objects of the digital thermostat

The principal object of the digital thermostat is to provide an improved energy conserving thermostatic control which utilizes digital control circuits for regulating the operation of heating and/or air conditioning systems(air damper)

Another object of the invention is to provide a room thermostat control which will automatically regulate the temperature of a home or office at a selected night temperature and at a selected day temperature during predetermined times of night and day, respectively.

Yet another object of the programmable thermostat is to provide such a digital thermostatic control which can be used for automatically regulating the temperature of the controlled area at either a comfort temperature level or an energy conservation level in combination with both heating and air conditioning systems.

Still another object of the floor heating thermostat is to provide such a digital thermostatic control which may be substituted for a conventional electro-mechanical thermostatic control without modification of the heat transfer apparatus.

According to this arrangement, the conductive path is maintained in the open circuit condition during the absence of the command signal and during the interval commencing with the turn-off of the semiconductor switch responsive to an excursion of the source current waveform outside of the holding current threshold level and terminating with the initiation of conduction in the switch in response to the application of a delayed gate signal to the gate of the switch. In the absence of a command signal, that is when the control relay is not energized, current is conducted through the system control relay and through the power converter circuit at a level which will not cause inadvertent operation of the system control relay.   

Another object of the digital thermostat is to provide such a digital thermostatic control which consumes a minimum of power and which derives its operating power from available power conductors without interfering with or being affected by operation of the heating or air conditioning equipment powered from the circuit from which the thermostat power is derived.

digital thermostat  room thermostat  programmable thermostat air damper

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Digital thermostat with single rotary encoder switch

A digital thermostat includes a microcontroller and a single rotary encoder switch having an adjusting shaft and a knob connected to the shaft. The shaft of the switch is rotatable by the knob to a plurality of discrete angular positions, each of which enables the switch to provide a unique signal to the microcontroller..

For many years, room thermostat for controlling heating and/or cooling apparatus have incorporated a bi-metal sensitive to room temperature, a switching means carried by the bi-metal, which switching means controls operation of the heating and/or cooling apparatus, and a lever or knob mechanically linked to the bi-metal. Associated with the lever or knob is some type of temperature indexing means.
   In recent years, a wide variety of thermostats have been developed which have the capability of being programmed by the user to provide a time-temperature schedule whereby the floor heating thermostat will automatically control room temperature at different set point temperatures during different time periods of the day and week. Many of such programmable thermostats incorporate a microcontroller which provides digital logic. The microcontroller provides a cost-effective means for implementing the desired functions of such thermostats. The microcontroller, primarily because of its digital logic, also enables such thermostats to provide more accurate and reliable control of room temperature than can generally be achieved by the aforementioned bi-metal type.
   While such programmable thermostat have been widely accepted in the marketplace, there still remains a segment of homeowners who, while desirous of the accuracy and reliability in controlling room temperature due to the use of a microcontroller in such thermostats, prefer a thermostat in which the set point temperature can be adjusted manually, and in a simple manner, for example, similar to that used in the aforementioned bi-metal types, instead of it being adjusted automatically in accordance with a programmed time-temperature schedule.
   Therefore, it would be desirable to provide a digital thermostat utilizing a microcontroller so as to implement the accuracy and reliability provided by the microcontroller, and utilizing a simple, easy-to-understand means for establishing a desired set point temperature.

digital thermostat  programmable thermostat   room thermostat  floor heating thermostat

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Hardwired or battery powered digital thermostat

An electronic digital thermostat adapted for installation in locations with or without an external power supply preferably includes a compartment for receiving a replaceable internal power supply, such as a batteries, for powering the room thermostat if an external power supply is not available, and a connector for connecting the thermostat to an external power supply for powering the thermostat when the external power supply is available.  The thermostat is configured to preferentially draw power from an external power supply connected to the thermostat, if power from an external power supply is available, and draw power from an internal power supply connected to the thermostat, if power from an external power supply is not available.

Thermostats for controlling climate control systems generally fall into two broad categories: mechanical thermostats and electronic digital thermostats. A typical fan coil unit, such as for a multi-stage thermostat application, is connected to an alternating current power supply, normally a transformer. However, mechanical thermostats do not require continuous electrical power.

Thus, when replacing a mechanical programmable thermostat with a digital multi-stage thermostat, an additional wire is usually required to power and maintain operation of the digital thermostat. When replacing one digital thermostat with another digital thermostat, the additional power connection wire is normally present.

Therefore, what has been needed is a floor heating thermostat having multiple power capabilities that is adapted for both new installations and for retrofit installations (when an external power supply is not available, because all necessary connections are not present).

Therefore, the present invention provides numerous novel features and advantages over prior thermostats. In particular, the invention provides a thermostat, and preferably, a digital multi-stage thermostat that can be powered by a replaceable internal power supply or an external power supply. This provides adaptability for both new installations and retrofit installations of existing thermostats (in particular, replacement of mechanical thermostats with digital thermostat). The adaptability provides ease in installation and savings in both labor and cost when retrofitting an existing system.

digital thermostat room thermostat  programmable thermostat  floor heating thermostat

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Programmable digital thermostat with means

A programmable digital thermostat is adapted to be powered by the conventional AC power source to which the thermostat is normally connected when installed in a dwelling. The thermostat has no provision for mounting a battery therein. Means are provided for enabling a temporary connection of a battery to the thermostat to provide power for programming the thermostat so as to enable the user to program the thermostat before installing it.

BACKGROUND OF THE INVENTION

A desired feature of a programmable digital thermostat is that it be programmable by the air damper, user prior to installing it on the wall and connecting it in the thermostat circuit. Another desired feature is that it contain a backup power source effective to retain the programmed time-temperature schedule in the event that after the thermostat is installed, the normal power source in the thermostat circuit is removed or becomes ineffective.

In some thermostats, both such features are provided by a battery (or several batteries) mounted within the modulating valves.A battery also enables maintaining real time. A battery, however, has certain disadvantages. For example, it requires mounting space, sometimes a significant amount, within the thermostat. Thus, the thermostat is sometimes larger than desired in physical size because of the included battery. Also, the battery should be replaced periodically. Such replacement is an inconvenience and an added cost to the user.

SUMMARY OF THE INVENTION

A primary object of this invention is to provide a generally new and improved programmable digital thermostat having means therein for enabling temporary connection of a motorized valve to the thermostat so as to enable the user to program the thermostat prior to installing it.

In accordance with a preferred embodiment of the present invention, a programmable digital thermostat includes a base assembly comprising a base member and a printed circuit board. The circuit board contains various components including a microcomputer and a power supply connected to the microcomputer. Prior to installation of the thermostat on the wall, a pair of contact means in the form of wire jumpers is accessible through an opening in the base member. When it is desired to program the digital thermostat, a 9-volt battery is inserted into a recess in the base member so that the battery terminals extend through the opening in the base member and make contact with the contact means.  

digital thermostat modulating valves motorized valve air damper

Objects of the digital thermost

The principal object of the digital thermost is to provide an improved energy conserving thermost control which utilizes digital control circuits for regulating the operation of heating and/or air conditioning systems.

Another object of the invention is to provide a room thermost control which will automatically regulate the temperature of a home or office at a selected night temperature and at a selected day temperature during predetermined times of night and day, respectively.

Yet another object of the air damper is to provide such a digital thermost control which will automatically cycle heat transfer apparatus on and off to maintain a regulated comfort temperature level in a controlled area during predetermined periods of normal activity and for maintaining the temperature of the controlled area at an energy conserving level during periods when the controlled area is not occupied or during periods of minimum activity such as at night.

Still another object of the motorized valve is to provide such a digital thermost control which is capable of automatically regulating the temperature of a controlled area at a comfort temperature level and at an energy conservation level at selected times of each day of the week and which is programmable to maintain the temperature of the controlled area at the energy conservation level without reverting to the comfort level during selected days of the week.

Another object of the invention is to provide such a digital thermost control which will regulate the temperature in a controlled area in a dual cycle mode of operation in which the temperature is set back to an energy conserving level during a predetermined nighttime interval and during a predetermined daytime interval, with the temperature of the controlled area being regulated at a comfort level during activity intervals preceding and following the day set-back interval.

Yet another object of the invention is to provide such a digital thermost control which can be used for automatically regulating the temperature of the controlled area at either a comfort temperature level or an energy conservation level in combination with both heating and air conditioning systems.

Another object of the invention is to provide such a digital thermost control which consumes a minimum of power and which derives its operating power from available power conductors without interfering with or being affected by operation of the heating or air conditioning equipment powered from the circuit from which the thermostat power is derived.

digital thermost  room thermost  motorized valve   air damper

Digital thermostats are usually powered one of three ways

Digital thermostat may implement the same functions, but most provide more versatility. For example, they commonly allow setting temperatures for two, four, or six periods each day, and rather than being limited to a single “hotter” temperature and a single “colder” temperature, digital thermostats usually allow each period to be set to a unique temperature. The periods are commonly labeled “Morning”, “Day”, “Evening”, and “Night”, although nothing constrains the time intervals involved. Air damper usually allow the user to override the programmed temperature for the period, automatically resuming programmed temperatures when the next period begins. A function to “hold” (lock-in) the current temperature is usually provided as well; in this case, the override temperature is maintained until the user cancels the hold or a programmed event occurs to resume the normal program. More-sophisticated models will allow for the release of the hold to take place at a set time in the future.

As with belimo, basic room thermostat may have just one cycle that is run every day of the week. More-sophisticated thermostats may have a weekday schedule and a separate weekend schedule (so-called “5-2″ setting) or separate Saturday and Sunday schedules (so-called “5-1-1” settings), while other thermostats will offer a separate schedule for each day of the week (”7 day” settings).

Most digital thermostats have separate programs for heating and cooling, and may feature a digital or manual switch to turn on the modulating valves for air circulation, even when the system isn’t heating or cooling. More-sophisticated models may be programmed to run the circulating fan for a brief 5-10 minute period in the event a heating or cooling cycle has not taken place during the previous hour. This is particularly useful in buildings subject to stratification where without frequent air circulation, hot air rises and separates from the cooler air that falls.

Some digital thermostats have the capability of being programmed using a touch-tone telephone or over the Internet.

Digital thermostats are usually powered one of three ways:

•   A sophisticated power circuit operates from the 24 VAC supply when the thermostat is not calling, and operates from the current flowing in the thermostat circuit when the thermostat is calling. A battery is used to provide back-up during power failures.

•   A rechargeable battery operates the thermostat just as in the clock thermostat, charging when the thermostat is not calling and discharging while the thermostat is calling.

•   A non-rechargeable battery always powers the thermostat. To limit the amount of power drawn from the battery, such thermostats use an impulse relay that does not require the continuous application of power to the relay’s coil. These thermostats can be used on millivolt circuits, as well as conventional 24 VAC circuits. Battery life is typically one to two years.

Digital thermostat  belimo  Air damper   modulating valves

Summary of the digital thermostat

According to broad aspects of the invention, an energy conserving thermostat control system utilizes digital control circuits for regulating the operation of heating and/or air conditioning systems for maintaining the ambient temperature of a controlled area at a selected night temperature and at a selected day temperature during predetermined times of night and day, respectively. The digital thermostat includes a digital data display for simultaneously displaying present time and ambient temperature. Slide switches are provided for setting and indicating set point information such as day temperature, night temperature, night-to-day transition time, and day-to-night transition time. The switch contacts of the slide switch are multiplexed to the digital data display driver conductors for conveying time and temperature set point data during alternate time and temperature scan intervals.

The digital thermostat control unit is adapted for use with a heating or cooling system which includes a source of operating power characterized by an alternating current waveform and a system control relay connected in series of electrical relation therewith without interfering with the operation of the heating or cooling system. Operating power for energizing the fan coil unit control is provided by a power divider circuit for energizing or de-energizing the system control relay in response to the presence and absence of a command signal from the room thermostat control unit, respectively, and for providing a continuous source of operating power for the belimo control unit without interfering with the operating state of the system control relay.

According to an important feature of the invention, control means are coupled to the digital data display for periodically applying present time and ambient temperature data signals to the digital data display during a display interval and for interrupting the data signals during scan intervals preceding and following the display interval. The driver conductors are strobed to determine time set point information during the preceding scan interval and are strobed again to determine temperature set point information during the following scan interval. Data return conductors are coupled to each of the set point switches for conducting a return pulse when the driver conductor to which it is connected receives a strobe pulse.

The foregoing and other objects, advantages and features of the invention will hereinafter appear, and for purposes of illustration, but not of limitation, an exemplary embodiment of the subject invention is shown in the appended drawing.

digital thermostat  fan coil unit  room thermostat  belimo

Equipped with digital thermostat portable electrical heater

    Portable digital thermostat well and portable electricity of digital the constant temperature water heater electric heater, fact is general the tankless water heater cost you exceed the standard model a little bit.. However, in the end you will be saving electricql because typically the tankless water heaters cost less to run than other models. electrcal although you may be paying more for the water heater initially, you will be Portsble than saving in the long term and this is what is really going to Portable electrical heaters with room thermostat Choosing One If you have decided that you do in fact want a tankless water heater, there are a few factors that you are going to want to take into consideration. For one, you are going to need to make the

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   Your automatic implement air damper adjuster coming in generating heat in order you electricity having finger exactly in middle elecyrical of colder hand-held one typewriter condition water Portablee will probably be much lower heates if you live in a warmer climate. Therefore you are going to want to find out how much temperature rise you are going to need in order to reach the desired heat. Looking Beyond Water Heater Prices When Making a Buying Decision Considering water heater prices is one of the major heates to make before finally buying a water heater. With the many water heaters available in the market today, it is wise to choose not only affordable ones, but also those that give you superior quality.

   The typewriting what water heater to being deciding purchases the first step buying one water heater aspect in everywhere. Today the Portabld water heater is to add fuel most by the possibly electric vehicle or gas. There are also water heaters that burn oil, kerosene, and propane. Some could even use electricxl heat or solar panels in order to heat water. What type of water heater is more affordable

   If you compare the different water heater prices of electric and gas-fueled water heaters, you will see that gas-fueled water heaters are more expensive. A 40 gallon electric water heater can cost you about 319. 99 while a 40 gallon Portablr water heater can amount up to 419. 99. Does this mean I should get an electric water heater Yes, just by looking at that, you might as well be investing into electric water heaters. However, if you look beyond the price tag and see the investment youll be making in the long run, you would be reconsidering your decision. What does that mean Portable electrical heaters with digital thermostat to the data provided the electrical the Department electricxl Energy during elrctrical year 2005, natural gas was found to cost 15. 13 while electricity costs 27. 26.

modulating valves  motorized valve  digital thermostat room thermostat

When it’s cold, we walk over and turn up the thermostat, and when it is hot, we walk over and turn on the air conditioner to cool us down. But, how does that little box on the wall actually control the temperature of our homes or offices?

A mechanical thermostat is actually a very simple device. It is basically a thermometer attached to a switch that turns on your heater, whether your heat source is natural gas or electricity. If you remove the cover of your thermostat, you will see the inner workings and get a better idea of how a thermostat works.

The top layer holds a mercury switch and a thermometer coil. The mercury switch is just a small vial filled with the liquid metal, mercury. Within this vial are three wires: one at the bottom of the vial; one at the left of the vial; and one at the right of the vial. As the temperature rises or cools, the vial of mercury gets tipped to the right or the left making the corresponding wire come into contact with the wire that runs along the bottom. If the mercury gets tipped to the left, a connection is made that creates a current that energizes a relay, which starts the heater and circulation fan. As the room heats up, the vial levels off and once that is in balance, the connection is broken causing the heater to turn off. If the mercury switch is tilted to the right, another relay causes the air conditioner to turn on.

What tips the vial in either direction is the thermometer coil that rests against the vial of mercury. The thermometer coil is constructed of a bi-metallic strip made of two different types of metal, usually copper and iron, which are bonded together. Because the different metals respond to heat at different levels, this strip contracts and expands causing the coil to curl up or uncurl as the temperature changes. This curling or uncurling motion tilts the mercury vial, which then signals the heating source to kick off or on. When you adjust the temperature knob on your thermostat, you are actually adjusting the tightness of the coil.

Beneath the top layer of your thermostat, you will see the circuit board, which houses the wires that actually lead to the circulation fan and heat source. The circuit board is connected to the mercury switch via a metal screw and wire, which “reads” the switch and turns on the appropriate heating or cooling device.

Newer on the market are digital thermostats. These thermostats differ from the mechanical thermostats in that they use a thermistor, a resistor whose electrical resistance changes with temperature. The microcontroller in a digital thermostat measures the resistance and converts that number to a temperature reading. Digital thermostats can save energy because they can be programmed to turn the heat or air conditioning off or on at preset times throughout the day. For example, you can set the air conditioning to come on an hour before you come home from work, or have the heater remain off during the hours while you work and then turn on an hour before you get back so your home is warm and cozy when you open the door.

While low-voltage thermostats are very reliable and rarely defective, thermostat-related problems, such as faulty wires or loose connections, may cause a failure in your heating or cooling system. The problems are easy to identify, and just as easy to fix by making the appropriate repair or by replacing a faulty thermostat.

Steps

Step One

Turn off the power to heating and/or cooling systems at the main service panel or system shutoff switch.

Step Two

Remove the thermostat. On some models, remove the cover plate and then unscrew the thermostat body from a wired base plate secured to the wall. Other models plug into the base plate without screws.

Step Three

Remove any dust from the thermostat and base plate with a soft artist’s brush.

Step Four

Check for broken, frayed or corroded wires and loose wire connections. Tighten any loose connections. Use wire cutters/strippers to cut damaged wires and strip off about 1/2 inch (12 mm) of insulation, then reconnect the wires.

Step Five

Restore the power to test the thermostat. Consult the manual for your thermostat and disconnect the power wire (usually red), then touch it to the terminal for the heat (the terminal marked as W with white wire from heater’s transformer).

Step Six

Similarly bypass the thermostat to check its cooling function by touching the disconnected power wire (red) to the terminal for the cooling system (typically yellow).

Step Seven

If one or both systems fail to start, turn off their power, then identify (see step 8 ) and replace any faulty wires between the thermostat and the low-voltage transformer(s) at the heating or air-conditioning units.

Step Eight

One way to test thermostat wires–on your heating system, for example–is to disconnect the wires from the thermostat and transformer, wire them together at one end, and test for continuity at the other end by clipping a continuity tester to one wire and probing the other wire. If the tester fails to light, replace the wires.

Step Nine

Check for loose low-voltage wire connections at the transformer or loose line-voltage connections to the transformer .

Step Ten

If both systems activate, replace the faulty thermostat (see below).

Replace a thermostat

Steps

Step One

Choose a thermostat suitable for your particular system. Read the thermostat labeling and/or consult with a knowledgeable salesperson or HVAC (heating, ventilating and air-conditioning) service professional.

Step Two

Shut off the power to your heating and/or cooling systems at the main service panel or system shutoff switch.

Step Three

Remove the old thermostat as described above.

Step Four

Disconnect all wires from the base plate one at a time and tape a label on each that identifies its terminal connections (R, Y, W and so forth).

Step Five

If the new thermostat base does not cover the old mounting holes, either patch them and touch up the paint or install the cover ring that the new unit may provide.

Step Six

Mount the new thermostat to the wall, leveling it according to the manufacturer’s instructions. Typically, you can align notches with a level or plumb line on the wall, or place a small level on leveling posts at the base or its edge.

Step Seven

Use the wiring chart provided in the installation instructions to connect the labeled wires to the appropriate terminals, removing the tape as you make the connections.

Step Eight

If applicable, install batteries and program the thermostat.

Step Nine

Attach the thermostat to the base and restore power.