Method of electronic control

• US 6,031,870 A
• Filed: 06/13/1997
• Issued: 02/29/2000
• Est. Priority Date: 11/29/1994
• Status: Expired due to Fees

• Current Assignee: Gallaher Group Limited (Government of Japan)
• Original Assignee: Gallaher Group Limited (Government of Japan)
• Inventors: Walley, John Leonard
• Primary Examiner(s): VO, DON NGUYEN
• Application Number:
  US08/860,351
• Time in Patent Office: 991 Days
• Field of Search: 375/317, 375/221, 375/207, 375/231, 375/239, 375/256, 375/285, 256/10, 307/106, 307/107, 307/108
• US Class Current: 375/239
• CPC Class Codes: H04B 1/10 Means associated with receiver for limiting or suppressing noise or interference
• CPC Class Codes: H05C 3/00 Other circuits or apparatus

Abstract

A method and device for detecting on an electric fence system a communication signal from a total signal including noise and also electrical interference from electrical energizer pulses supplied to the fence. A signal detector detects, directly or indirectly, the level of noise or electrical interference in the total signal on the system, at least one of a filter associated with the signal detector and the amplitude of the total signal received is adjusted until the threshold of the filter blocks sufficient electric noise so that a sufficient part of the total signal received after filtering is the communication signal, and the adjustment of the filter threshold is not dependent on the communication signal alone. The validity of the communication signal is checked and the electrical energizer pulses are transmitted on the fence system in coordination with reception of the communication signals to reduce the interference.

Claims

1. A method of detecting on an electric fence system a communication signal from a total signal including noise and electrical interference from electrical energizer pulses supplied to the fence, comprising:

detecting directly or indirectly by a signal detector the level of noise or electrical interference in the total signal on the system,

adjusting a filter associated with said signal detector to adjust the total signal received until the threshold of the filter blocks sufficient electric noise so that a sufficient part of the total signal received after filtering is a communications signal, whereby adjustment of the filter threshold is not dependent on the communication signal alone,

validity checking the communication signal; and

transmitting the electrical energizer pulses on the fence system in coordination with reception of the communication signals to reduce interference.

2. A method as claimed in claim 1 wherein the filter is adjusted until no or minimal noise passes through the filter to said signal detector.

3. A method as claimed in claim 1, which further comprises adjusting the filter level either up or down until a recognizable communication signal is detected.

4. A method claimed in claim 1, wherein the filter threshold is reset on a periodic basis.

5. A method as claimed in claim 1, which further comprises:

sending a reference waveform along the system;

comparing the reference waveform with a stored reference waveform; and

setting the filter level in accordance with the difference between the two waveforms.

6. A method as claimed in claim 1, which further includes the step of measuring both the noise communication signal and filtering out the noise signal using a software filtering technique.

7. A method as claimed in claim 1, which further comprises maintaining a predetermined signal/noise ratio.

8. A method as claimed in claim 1, wherein adjustment of the filter level takes into account gradual changes in the noise on the system.

9. A method as claimed in claim 1, further comprising instructing a transmitter which sends the communication signal to retransmit the communication signal at a boosted level.

10. A method as claimed in claim 1, further attenuating the total signal to bring the noise level below a filter threshold.

11. Apparatus for detecting on an electric fence system a communication signal from a total signal including noise and electrical interference from electrical energizer pulses supplied to the fence, comprising:

a signal detector for detecting directly or indirectly the level of noise or electrical interference in the total signal on the system,

means for adjusting of a filter associated with said signal detector to adjust the amplitude of the total signal received until the threshold of the filter blocks sufficient electric noise so that a sufficient part of the total signal received after filtering is a communications signal, whereby adjustment of the filter threshold is not dependent on the communication signal alone,

means for validity checking the communication signal, and

means for transmitting the electrical energizer pulses on the fence system in coordination with reception of the communication signals to reduce interference.