Sensor

• US 20060037380A1
• Filed: 07/15/2005
• Published: 02/23/2006
• Est. Priority Date: 01/17/2003
• Status: Active Grant

• Current Assignee: EnOcean GmbH
• Original Assignee: EnOcean GmbH
• Inventors: Bulst, Wolf-Eckhart, Sczesny, Oliver, Schmidt, Frank
• Granted Patent: US 7,389,674 B2
• Time in Patent Office: Days
• US Class Current: 73/29.10
• CPC Class Codes: G01D 3/08 with provision for safeguarding the apparatus, e.g. against abnormal operation, against breakdown
• CPC Class Codes: G01D 9/005 Solid-state data loggers

Abstract

An energy-autonomous sensor for detection of physical environmental parameters, having at least one sensor element, one storage element and one control circuit, with a timer circuit which is activated on reaching a predetermined electrical voltage on the storage element, activates the sensor and the control circuit at predetermined time intervals, and deactivates them after a predetermined operating time, such that this results in a time duration of sensor operation and a sensor operation pause.

Claims

1. An energy-autonomous sensor (1) for detection of physical environmental parameters, comprising

one storage element (3) for storage of electrical energy,

one sensor element (4) for detection of physical environmental parameters,

one control circuit (5) for coding of the detected physical environmental parameters,

a photovoltaic element (2) which is connected to the storage element (3) in order to supply power to the sensor (1), and

a timer circuit (12) which is activated upon a predetermined electrical voltage on the storage element (3) being reached, activates the sensor element (4) and the control circuit (5) at a predeterminable time interval, and deactivates them after a predeterminable operating time, such that this results in a time duration of sensor operation and time duration of a sensor operation pause.

2. The sensor (1) as claimed in patent claim 1,

wherein

the time duration of sensor operation is considerably shorter than the time duration of the sensor operation pause.

3. The sensor (1) as claimed in claim 1,

wherein

on each activation of the control circuit (5), the time interval for activation of the control circuit (5) is redefined as a function of the state of charge of the storage element (3).

4. The sensor (1) as claimed in claim 1,

wherein

the time interval for activation of the control circuit (5) is redefined as a function of the illumination intensity at the photovoltaic element (2) at the activation time.

5. The sensor (1) as claimed in claim 4,

wherein

the photovoltaic element (2) is designed to be smaller than is required for direct operation of the sensor (4) with the control circuit (5).

6. The sensor (1) as claimed in claim 1, further comprising:

a radio-frequency transmitter (6) producing a radio-frequency signal or radio message.

7. The sensor (1) as claimed in claim 1,

wherein

the storage element (3) is a capacitor and/or an electrochemical energy store.

8. The sensor (1) as claimed in claim 1,

wherein

the sensor element detects the moisture or humidity as the physical environmental parameter.

9. The sensor (1) as claimed in claim 1, further comprising at least two electrodes (13) for performing a moisture or humidity measurement via an impedance measurement.

10. The sensor (1) as claimed in claim 1,

wherein

the radio-frequency transmitter (6) has a very short stabilization time.

11. The sensor (1) as claimed in claim 1,

wherein

a surface acoustic wave resonator (14) is the frequency-determining component of the radio-frequency transmitter (6).

12. The sensor (1) as claimed in claim 1,

wherein

the radio-frequency transmitter (6) transmits with a wide bandwidth.