Method and circuit for determining if seed sensor is operably connected to seed monitor system
US5831541A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1997 |
| Grant date | Nov 3, 1998 |
| Priority date | — |
| Expiry date | May 14, 2017 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA01C7/105
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method and circuit for determining whether a sensor 2 is attached to a connection point 5 of a sensor interface circuit 1 of a seed monitoring system. When it is desired to determine whether a sensor is attached to a connection point, the method applies a time varying detection signal at terminal 3 to the connection point 5 via a reactive element, such as capacitor 4. The connection point 5 is connected to a first input of a comparator 9 having its other input set at a first reference voltage which maintains the comparator in a first state in the absence of a detection signal being applied. Even when a detection signal is applied, the comparator is not driven into a second state if an operable sensor is connected to the connection point 5. When the sensor is not connected to the connection point, or is inoperable, the voltage produced by the detection signal at the first input of the comparator is high enough to trip the comparator into a second state, which may be latched. Thus, the interface output 7 following a detection signal provides an indication whether an operable sensor is connected to the seed monitoring system at the connection point 5. In a preferred embodiment, the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.