Dehumidifier with temperature sensor safety feature

Abstract

We provided a dehumidifier with a temperature-sensing safety feature. The temperature probe is in direct contact with the discharge tube, as opposed to the industry standard of measuring temperature at the evaporator. In case the discharge tube overheats, it causes the resistance of the temperature probe to increase above a threshold value. The temperature probe then sends a signal to pause operation of the compressor. In a preferred embodiment, the compressor resumes operation when the temperature returns to normal, unless it overheats repeatedly. The temperature probe remains intact and may be used indefinitely. In preferred embodiments, the temperature-sensing safety feature is combined with a timing safety feature and/or a current-sensing safety feature.

Claims

1. A dehumidifier with a temperature sensor safety feature and a timing safety feature, comprising: a compressor, a discharge tube, and a control panel; a microcontroller for electronic control of the dehumidifier; a temperature measuring sensor comprising a temperature probe in contact with the discharge tube, plug wire ports connected to the microcontroller, and a lead allowing transfer of an electric signal from the temperature probe to the plug wire ports; a threshold resistance level for the temperature probe; wherein an increase in discharge tube temperature causing the resistance of the temperature probe to fall below its threshold resistance level causes an overheating signal to pass to the microcontroller; and wherein the microcontroller is programmed to pause operation of the compressor when the microcontroller receives the overheating signal; and wherein the temperature probe remains intact after discharge tube overheating; a driver chip connected to the microcontroller; a lead port of compressor control connected to the driver chip; a compressor relay connected to the lead port of compressor control; wherein the microcontroller is programmed with a first pre-set time for operation and a second pre-set time for pauses; and wherein, when the first pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to open by sending a command through the lead port of the compressor control; and wherein, when the second pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to close by sending a command through the lead port of the compressor control; and wherein the compressor can operate if and only if the compressor relay is closed; and wherein the opening and closing of the compressor relay repeat in a cycle until the power supply is shut off.

2. A dehumidifier with a temperature sensor safety feature and a current detector safety feature, comprising a compressor, a discharge tube, and a control panel; a microcontroller for electronic control of the dehumidifier; a temperature measuring sensor comprising a temperature probe in contact with the discharge tube, plug wire ports connected to the microcontroller, and a lead allowing transfer of an electric signal from the temperature probe to the plug wire ports; a threshold resistance level for the temperature probe; wherein an increase in discharge tube temperature causing the resistance of the temperature probe to fall below its threshold resistance level causes an overheating signal to pass to the microcontroller; and wherein the microcontroller is programmed to pause operation of the compressor when the microcontroller receives the overheating signal; and wherein the temperature probe remains intact after discharge tube overheating; a driver chip connected to the microcontroller; a compressor relay connected to the driver chip; a current transformer; a peripheral circuit; wherein the current transformer converts the current through the compressor into a voltage signal and relays the voltage signal to the microcontroller via the peripheral circuit; and wherein the microcontroller is programmed with a threshold voltage level; and wherein, if the voltage signal ever exceeds the threshold voltage level, the microcontroller transmits a signal to the driver chip, causing the compressor relay to open, thereby halting operation of the compressor; and wherein, when the first pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to open by sending a command through the lead port of the compressor control; and wherein, when the second pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to close by sending a command through the lead port of the compressor control; and wherein the compressor can operate if and only if the compressor relay is closed; and wherein the opening and closing of the compressor relay repeat in a cycle until the power supply is shut off.

3. A dehumidifier with a timing safety feature, comprising a compressor, a discharge tube, and a control panel; a microcontroller for electronic control of the dehumidifier; a driver chip connected to the microcontroller; a lead port of compressor control connected to the driver chip; a compressor relay connected to the lead port of compressor control; wherein the microcontroller is programmed with a first pre-set time for operation and a second pre-set time for pauses; and wherein, when the first pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to open by sending a command through the lead port of the compressor control; and wherein, when the second pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to close by sending a command through the lead port of the compressor control; and wherein the compressor can operate if and only if the compressor relay is closed; and wherein the opening and closing of the compressor relay repeat in a cycle until the power supply is shut off.

4. A dehumidifier with a current detector safety feature, comprising a compressor, a discharge tube, and a control panel; a microcontroller for electronic control of the dehumidifier; a driver chip connected to the microcontroller; a compressor relay connected to the driver chip; a current transformer; a peripheral circuit; wherein the current transformer converts the current through the compressor into a voltage signal and relays the voltage signal to the microcontroller via the peripheral circuit; and wherein the microcontroller is programmed with a threshold voltage level; and wherein, if the voltage signal ever exceeds the threshold voltage level, the microcontroller transmits a signal to the driver chip, causing the compressor relay to open, thereby halting operation of the compressor; and wherein, when the first pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to open by sending a command through the lead port of the compressor control; and wherein, when the second pre-set time is reached, the microcontroller transmits a signal to the driver chip, causing the compressor relay to close by sending a command through the lead port of the compressor control; and wherein the compressor can operate if and only if the compressor relay is closed; and wherein the opening and closing of the compressor relay repeat in a cycle until the power supply is shut off.

Description

5. BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 shows the external physical structure of the dehumidifier compressor with the temperature sensor safety feature in place.

(2) FIG. 2 is an electronic diagram showing all relevant components for the temperature sensor, timing, and current sensor safety features.

(3) FIG. 3 is a flowchart of operation for the timing safety feature.

(4) FIG. 4 is a flowchart of operation for the current sensor safety feature.

6. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(5) FIG. 1 is relevant for the primary feature, the temperature sensor safety feature. The temperature sensor comprises a temperature probe (11), lead (12), and plug, wire port (13). The temperature probe has the property that, when its temperature increases, its electrical resistance decreases. For example, the temperature probe could be a thermistor with a negative temperature coefficient. A preset threshold resistance level indicates the safe range of operating temperature. The temperature probe is mounted to the discharge tube (15) leading out of the compressor (14). Information about the temperature probe's resistance, and thus its temperature, is conveyed through the lead and the plug wire port into the dehumidifier's microcontroller (21), shown in the circuitry of FIG. 2. When the temperature probe falls below its threshold resistance level, it passes a signal to the microcontroller that the discharge tube is too hot. This is called the overheating signal. The microcontroller then sends a signal to pause operation of the compressor (14).

(6) Unlike the Barito invention as limited in claims 3, 4, and 7, our temperature probe is not destroyed by overheating. After the discharge tube (15) cools to normal operating temperature, the resistance of the temperature probe (11) increases. When the resistance of the temperature probe rises above its threshold resistance level, it sends a signal to the microcontroller indicating that the discharge tube has returned to normal operating temperature. This is called a normal-temperature signal. The microcontroller (21) then sends a signal to resume operation of the compressor (14). If overheating continues recurringly, the microcontroller finally sends a signal to halt operation of the compressor. The microcontroller also sends an error code to be displayed on the control panel (not shown). At that point, the user should check the dehumidifier for recharging or other maintenance. After the problem is resolved, the temperature probe does not need to be repaired or replaced. It is still intact for continued use.

(7) The electronics of FIG. 2 include the components necessary for the secondary timing safety feature. FIG. 3 summarizes the sequence of steps for this safety feature. When the power (20) is turned on, the microcontroller (21) operates the compressor (14) normally according to the user's selected mode and the ambient humidity level. The microcontroller is in a first timing state (31), which means that it is counting, down a first pre-set time. Barring any system failures, the dehumidifier runs continuously until the first pre-set time is reached. The microcontroller then transmits a signal to a driver chip (22), setting a compressor relay (24) to a shutdown protection state by sending a command through the lead port of the compressor control (23). The microcontroller is now in a second timing state (32), which means that it is counting down a second pre-set time. After the second pre-set time has elapsed, the compressor relay closes, and the compressor reconnects for continuous operation. This cycle continues (33) until the power is shut down.

(8) The electronics of FIG. 2 also include the components necessary for the secondary current detector safety feature. FIG. 4 summarizes the sequence of steps for this safety feature. After the power (20) is turned on, the microcontroller (21) controls the compressor (14) according to humidity and mode. The microcontroller is in a third timing state (41), meaning that it times down a third pre-set time. A current transformer (25) measures the current through the compressor (14). The current transformer converts the compressor current into a voltage signal and sends it to the microcontroller via a peripheral circuit (26). When the third pre-set time is reached, the microcontroller begins to continuously sample the voltage signal. If the voltage ever exceeds a pre-set threshold called the threshold voltage level (42), a signal is relayed from the microcontroller to the driver chip (22) and then to the compressor relay (24), and the machine stops running.

(9) In the claims, the terms that follow are defined as presented above in the context of the invention:

(10) Compressor, compressor relay, control panel, current detector safety feature, current transformer, dehumidifier, driver chip, first pre-set time, lead, lead port of compressor control, microcontroller, normal-temperature signal, overheating signal, peripheral circuit, plug wire ports, second pre-set time, temperature measuring sensor, temperature probe, temperature sensor, temperature sensor safety feature, third pre-set time, threshold resistance level, threshold voltage level, timing safety feature, voltage signal.