Patent Application
20070268066
The present invention can be more fully understood by reading the following detailed description of the preferred embodiments, with reference made to the accompanying drawings, wherein:
The present invention is described by the following specific embodiments. Those with ordinary skills in the arts can readily understand the other advantages and functions of the present invention after reading the disclosure of this specification. The present invention can also be implemented with different embodiments. Various details described in this specification can be modified based on different viewpoints and applications without departing from the scope of the present invention.
The method and device for stably controlling a remote loading voltage according to the present invention is described in details in conjunction with
As shown in
The individual characteristics and functionality of each element 110, 120 and 130 of the device for stably controlling a remote loading voltage 100 of the present invention are explained below.
The loading voltage detecting module 110 is coupled to two terminals of the loading voltage of the terminal device 20 at a remote site. The loading voltage detecting module 110 is used to detect the loading voltage VL actually received in response to the provision of an output voltage Vo from the power supply 10 to the terminal device 20 via the conductive lines 30 and 31. In actual implementation, the loading voltage detecting module 110 is a differential amplifier. Two terminals of the differential amplifier are respectively connected to the two terminals of the terminal device 20, so as to detect the potential difference between these two terminals of the terminal device 20 and thus determine the loading voltage VL.
The comparison module 120 compares the loading voltage value VL actually detected by the above loading voltage detecting module 110 with the rated loading voltage value VRef of the terminal device 20 (the actual value of VRef is controlled for example by the system main control unit 11, that is, the user may set VRef via software and the setting of VRef is then sent from the system main control unit 11 to the comparison module 120). If the actual loading voltage value VL is approximately equal to the rated loading voltage value VRef of the terminal device 20 (i.e. VL=VRef), then the comparison module 120 sends a zero differential signal; if the actual loading voltage value VL is greater than the rated loading voltage value VRef of the terminal device 20 (i.e. VL>VRef), then the comparison module 120 sends a positive differential signal; else if the actual loading voltage value VL is less than the rated loading voltage value VRef of the terminal device 20 (i.e. VL<VRef), then the comparison module 120 sends a negative differential signal. In actual implementation, the comparison module 120 is for example an analog or digital comparator that outputs a positive voltage as the positive differential signal when VL>VRef and outputs a negative voltage as the negative differential signal when VL<VRef.
The current adjusting module 130 outputs a loading current IL to the terminal device 20 in response to the output voltage Vo, of the power supply 10. Furthermore, it may boost its loading current IL when a negative differential signal is outputted by the above comparison module 120 until the loading voltage VL of the terminal device equals to its rated loading voltage (i.e. VL=VRef), such that the comparison module 120 sends out the zero differential signal.
The operations of the device for stably controlling a remote loading voltage 100 of the present invention in actual implementation are illustrated using an example.
Referring to
In the case of the comparison module 120 outputs a zero differential signal, the current adjusting module 130 will not adjust the loading current IL. On the opposite, if the comparison module 120 outputs a negative differential signal, the current adjusting module 130 responsively increases the loading current IL until the loading voltage VL of the terminal device equals to its rated loading voltage (i.e. VL=VRef), such that the comparison module 120 sends out the zero differential signal.
In summary, the present invention provides a method and device for stably controlling a remote loading voltage that can be coupled to an electronic system for stably controlling a remote loading voltage. When a power supply of the electronic system outputs a voltage to a remote terminal device, the loading voltage value actually received by the terminal device is continuously detected, and this detected loading voltage value is then compared with the predetermined rated loading voltage value; if the detected loading voltage is less than the rated loading voltage, then a loading current outputted to the terminal device is increased until the loading voltage at the terminal device is equal to the rated loading voltage. This allows a constant loading voltage to be received by the remote terminal device even over long conductive lines, so that the loading voltage will not be attenuated over distance. Thus, the present invention is useful and inventive over the prior art.
The above embodiments are only used to illustrate the principles of the present invention, and they should not be construed as to limit the present invention in any way. The above embodiments can be modified by those with ordinary skills in the arts without departing from the scope of the present invention as defined in the following appended claims.
10—power supply
30, 31—line resistance
20—terminal device (load)
10—power supply
11—system main control unit
20—terminal device (load)
30, 31—line resistance
100—device for stably controlling a remote loading voltage of the present invention
110—loading voltage detecting module
120—comparison module
130—current adjusting module
