Moisture sensor and control system for sprinklers and method therefor

• US 7,258,129 B1
• Filed: 03/10/2006
• Issued: 08/21/2007
• Est. Priority Date: 03/10/2006
• Status: Expired due to Fees

• Current Assignee: Michael J. Donahoo
• Original Assignee: Michael J. Donahoo
• Inventors: Donahoo, Michael J.
• Primary Examiner(s): Keasel; Eric
• Assistant Examiner(s): LEE, CLOUD K
• Application Number:
  US11/373,556
• Publication Number:
  US 20070209702A1
• Time in Patent Office: 529 Days
• Field of Search: 137/78.3, 239/64, 239/63, 73/73, 700/184
• US Class Current: 137/78.3
• CPC Class Codes: A01G 25/167 Control by humidity of the soil itself or of devices simulating soil or of the atmosphere; Soil humidity sensors
• CPC Class Codes: Y10T 137/189 Soil moisture sensing

Abstract

A landscaping watering system has a probe for monitoring a moisture content of an area. A control unit is coupled to the probe for sending an activation signal to activate a flow of water when a signal from the probe indicates the moisture content of the area is below a predefined level. The control unit sends a deactivation signal to stop a flow of water when a signal from the probe indicates the moisture content of the area is above a predefined level. A water solenoid valve is coupled to a water line, the control unit and to at least one sprinkler. The water solenoid valve will receive the activation and deactivation signals from the control unit to start and stop a flow of water from the water line to the at least one sprinkler.

Claims

1. A landscaping watering system comprising:

a probe for monitoring a moisture content of an area of soil;

a control unit coupled to the probe for sending an activation signal to activate a flow of water when a signal from the probe indicates the moisture content of the area of soil is below a predefined level and for sending a deactivation signal to stop a flow of water when a signal from the probe indicates the moisture content of the area is above a predefined level, wherein the control unit comprises;

a comparator having a first input coupled to the probe and a second input coupled to a set point;

a sample and hold circuit having an input coupled to an output of the comparator;

a driver having an input coupled to the output of the sample and hold circuit and an output coupled to the relay for increasing a strength of an output signal from the sample and hold circuit;

a relay coupled to the water solenoid valve; and

a processor coupled to the comparator, the sample and hold circuit, and the driver for programming the control unit; and

a water solenoid valve couple to a water line, the control unit and to at least one sprinkler for receiving the activation and deactivation signals from the control unit to start and stop a flow of water from the water line to the at least one sprinkler.

2. A landscaping watering system in accordance with claim 1 further comprising a photo sensor coupled to the control unit to allow activation of the landscaping watering system when a light level is below a predefined level.

3. A landscaping watering system in accordance with claim 1 further comprising:

wireless transmitter coupled to the control unit for in wirelessly transmitting the activation signal and deactivation signals; and

wireless receiver coupled to the water solenoid valve and in wireless communication with the wireless transmitter for receiving the activation and deactivation signals from the wireless transmitter.

4. A landscaping watering system in accordance with claim 1 further comprising a waterproof housing for protecting the control unit from the environment.

5. A landscaping watering system in accordance with claim 1 further comprising a transformer coupled to the control unit.

6. A landscaping watering system comprising:

a probe for monitoring a moisture content of an area;

a control unit coupled to the probe for sending an activation signal to activate a flow of water when a signal from the probe indicates the moisture content of the area is below a predefined level and for sending a deactivation signal to stop a flow of water when a signal from the probe indicates the moisture content of the area is above a predefined level, wherein the control unit comprises;

a comparator having a first input coupled to the probe and a second input coupled to a set point;

a sample and hold circuit having an input coupled to an output of the comparator;

a driver having an input coupled to the output of the sample and hold circuit and an output coupled to the relay for increasing a strength of an output signal from the sample and hold circuit; and

a relay coupled to the water solenoid valve; and

a water solenoid valve couple to a water line, the control unit and to at least one sprinkler for receiving the activation and deactivation signals from the control unit to start and stop a flow of water from the water line to the at least one sprinkler;

a photo sensor coupled to the control unit to allow activation of the landscaping watering system when a light level is below a predefined level; and

a transformer coupled to the control unit; and

a waterproof housing for protecting the control unit and transformer from the environment, the probe and the photo sensor extending out of the housing.

7. A landscaping watering system in accordance with claim 6 wherein the control unit further comprises a processor for programming the control unit.

8. A landscaping watering system in accordance with claim 6 further comprising:

a wireless transmitter coupled to the control unit for wirelessly transmitting the activation signal and deactivation signals; and

a wireless receiver coupled to the water solenoid valve and in wireless communication with the wireless transmitter for receiving the activation and deactivation signals from the wireless transmitter.