1. An apparatus for driving a light emitting device (LED), the apparatus comprising:
a first driving control element configured to control a current flowing through a first LED channel, which is connected to an operating voltage terminal and includes a plurality of LEDs, in response to a first pulse-width modulated control signal;
a first current detection unit connected between the first driving control element and a ground terminal, and configured to detect the current flowing through the first LED channel;
a first effective value detection unit configured to detect an effective value of the current detected by the first current detection unit;
a first reference signal generation unit configured to generate a preset reference signal having a sawtooth waveform; and
a first comparison unit configured to compare the reference signal from the first reference signal generation unit with the effective value from the first effective value detection unit, wherein
the first comparison unit is configured to be enabled when a dimming pulse-width-modulated (PWM) signal is at a high level, and disabled when the dimming PWM signal is at a low level.
2. The apparatus of claim 1, wherein the first driving control element is connected between the first LED channel and the first current detection unit, and comprises an NMOS transistor having a drain connected to the first LED channel, a gate receiving the first control signal from the first comparison unit, and a source connected to the first current detection unit.
3. The apparatus of claim 1, wherein the first current detection unit comprises a resistor connected between the first driving control element and the ground terminal.
4. An apparatus for driving a light emitting device (LED), the apparatus comprising:
a first driving control element configured to control a current flowing through a first LED channel, which is connected to an operating voltage terminal and includes a plurality of LEDs, in response to a first pulse-width modulated control signal;
a first current detection unit connected between the first driving control element and a ground terminal, and configured to detect the current flowing through the first LED channel;
a first effective value detection unit configured to detect an effective value of the current detected by the first current detection unit;
a first reference signal generation unit configured to generate a preset reference signal having a sawtooth waveform; and
a first comparison unit configured to compare the reference signal from the first reference signal generation unit with the effective value from the first effective value detection unit, wherein
the first comparison unit includes an operational amplifier having an inverting input terminal for receiving the reference signal from the first reference signal generation unit, a noninverting input terminal for receiving the effective value from the first effective value detection unit, and an output terminal for outputting the first control signal to the first driving control element,
the first control signal is pulse-width modulated by comparing the reference signal inputted through the inverting input terminal with the effective value inputted through the noninverting input terminal, and
the first comparison unit is configured to be enabled when a dimming pulse-width-modulated (PWM) signal is at a high level, and disabled when the dimming PWM signal is at a low level.
5. An apparatus for driving a light emitting device (LED), the apparatus comprising:
first to nth driving control elements controlling currents flowing through first to nth LED channels, which are connected in parallel to an operating voltage terminal and include a plurality of LEDs, in response to first to nth pulse-width modulated control signals, where n is an integer greater than 1;
first to nth current detection units connected between the first to nth driving control elements and a ground terminal, and detecting currents flowing through the first to nth LED channels;
first to nth effective value detection units detecting the effective values of the currents detected by the first to nth current detection units;
first to nth reference signal generation units generating preset reference signals having sawtooth waveforms; and
first to nth comparison units comparing the reference signals from the first to nth reference signal generation units with the effective values from the first to nth effective value detection units, and generating the first to nth pulse-width modulated control signals to the first to nth driving control elements.
6. The apparatus of claim 5, wherein the first to nth driving control element are connected between the first to nth LED channels and the first to nth current detection units, and comprise NMOS transistors having drains connected to the first to nth LED channels, gates receiving the first to nth control signals from the first to nth comparison units, and sources connected to the first to nth current detection units, respectively.
7. The apparatus of claim 5, wherein the first to nth current detection units comprise resistors connected between the first to nth driving control elements and the ground terminal, respectively.
8. The apparatus of claim 5, wherein the first to nth comparison units comprise operational amplifiers inverting input terminals receiving the reference signals from the first to nth reference signal generation units, noninverting input terminals receiving the effective values from the first to nth effective value detection units, and output terminals outputting the first to nth control signals to the first to nth driving control elements, the first to nth control signals being pulse-width modulated by comparing the reference signals inputted through the inverting input terminals with the effective values inputted through the noninverting input terminals, respectively.
9. The apparatus of claim 5, wherein the first to nth reference signal generation units generate the first to nth reference signals, which are synchronized with one another and have the same frequency, respectively.
10. An apparatus for driving a light emitting device (LED), the apparatus comprising:
first to nth driving control elements controlling currents flowing through first to nth LED channels, which are connected in parallel to an operating voltage terminal and include a plurality of LEDs, in response to first to nth pulse-width modulated control signals, where n is an integer greater than 1;
first to nth current detection units connected between the first to nth driving control elements and a ground terminal, and detecting currents flowing through the first to nth LED channels;
first to nth effective value detection units detecting the effective values of the currents detected by the first to nth current detection units;
first to nth reference signal generation units generating preset reference signals having sawtooth waveforms; and
first to nth comparison units enabled in response to a dimming pulse-width-modulated (PWM) signal, and comparing the reference signals from the first to nth reference signal generation units with the effective values from the first to nth effective value detection units, and generating the first to nth pulse-width modulated control signals to the first to nth driving control elements.
11. The apparatus of claim 10, wherein the first to nth driving control element are connected between the first to nth LED channels and the first to nth current detection units, and comprise NMOS transistors having drains connected to the first to nth LED channels, gates receiving the first to nth control signals from the first to nth comparison units, and sources connected to the first to nth current detection units, respectively.
12. The apparatus of claim 10, wherein the first to nth current detection units comprise resistors connected between the first to nth driving control elements and the ground terminal, respectively.
13. The apparatus of claim 10, wherein the first to nth comparison units comprise operational amplifiers inverting input terminals receiving the reference signals from the first to nth reference signal generation units, noninverting input terminals receiving the effective values from the first to nth effective value detection units, and output terminals outputting the first to nth control signals to the first to nth driving control elements, the first to nth control signals being pulse-width modulated by comparing the reference signals inputted through the inverting input terminals with the effective values inputted through the noninverting input terminals, respectively.
14. The apparatus of claim 10, wherein the first to nth reference signal generation units generate the first to nth reference signals, which are synchronized with one another and have the same frequency, respectively.
15. The apparatus of claim 10, wherein the dimming PWM signal is branched and provided to the first to nth comparison units.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. In a system that includes a plurality of nodes, the system being managed by a managing user and having a system operation that may be performed in a node by any user of the system,
a method of performing the system operation for a user in a node, the method comprising the steps performed in the system of:
responding to a first input from the user specifying performance of the operation in the node by obtaining a trust value associated with the user;
when the trust value so indicates, sending a message to the managing user, the message indicating that the user has specified performance of the system operation in the node and the managing user performing an action with regard to the message that indicates how the system operation is to be performed in the node; and
responding to the action by performing the system operation in the node as indicated by the action.
2. The method set forth in claim 1 wherein:
an action of not responding to the message within a predetermined period of time indicates that the system operation in the node is not to be performed.
3. The method set forth in claim 2 wherein:
the predetermined time is associated with the user.
4. The method set forth in claim 1 wherein:
an action of responding to the message within a predetermined period of time indicates that the system operation in the node is to be performed.
5. The method set forth in claim 4 wherein:
the predetermined time is associated with the user.
6. The method set forth in claim 1 wherein:
the action is responding to the message by providing a second input to the system indicating how the system operation is to be performed in the node; and
in the step of responding to the action, responding to the second input by performing the system operation in the node as indicated by the second input.
7. The method set forth in claim 6 wherein:
the second input indicates that the system operation is to be performed in the node for the managing user instead of for the user; and
in the step of responding to the action, the system responds to the second input by performing the system operation in the node for the managing user.
8. The method set forth in claim 6 wherein:
the second input indicates that the system operation is not to be performed in the node; and
in the step of responding to the action, the system responds to the second input by not performing the system operation in the node.
9. The method set forth in claim 1 wherein:
there is a plurality of actions which the managing user may perform with regard to the message; and
the actions include
not responding to the message within a predetermined period of time and
providing a second input to the system in response to the message within the predetermined period of time.
10. The method set forth in claim 9 wherein:
the predetermined time is associated with the user.
11. The method set forth in claim 9 wherein:
in the step of responding to the action,
when the action is not responding to the message, the system responds thereto by performing the system operation in the node for the user and
when the second input indicates that the system operation is not to be performed in the node, the system responds thereto by not performing the system operation in the node.
12. The method set forth in claim 9 wherein:
there is a plurality of the second inputs, including one second input that indicates that the system operation is not to be performed in the node and another second input that indicates that the system operation is to be performed in the node for the managing user; and
the system responds to the one second input by not performing the system operation in the node and to the other second input by performing the system operation in the node for the managing user.
13. The method set forth in claim 9 wherein:
in the step of responding to the action,
when the action is not responding to the message the system responds thereto by not performing the system operation in the node and
when the second input indicates that the system operation is to be performed in the node, the system responds thereto by performing the system operation in the node for the managing user.
14. The method set forth in claim 13 wherein:
there is a plurality of the second inputs, including one second input that indicates that the system operation is not to be performed in the node and another second input that indicates that the system operation is to be performed in the node for the managing user; and
the system responds to the one second input by not performing the system operation in the node and to the other second input by performing the system operation in the node for the managing user.
15. The method set forth in claim 1 wherein:
there is a plurality of the trust values; and
in the step of responding to the action, the manner in which the system responds depends on which trust value of the plurality is associated with the user.
16. The method set forth in claim 15 wherein:
the action is not responding to the message within the predetermined period of time; and
in the step of responding, the system responds when the action is not responding to the message within the predetermined period of time by not performing the system operation in the node when the trust value associated with the user is a first one of the trust values and performing the system operation in the node for the user when the trust value associated with the user is a second one of the trust values.
17. The method set forth in claim 4 wherein:
the predetermined time is associated with the user.
18. The method set forth in claim 16 wherein:
there is a plurality of actions which the managing user may perform with regard to the message;
the plurality of actions includes providing one of a plurality of second inputs to the system in response to the message within the predetermined period of time, the plurality of second inputs including one second input that indicates that the system operation is not to be performed in the node and another second input that indicates that the system operation is to be performed in the node for the managing user; and
the system responds to the one second input by not performing the system operation in the node and to the other second input by performing the system operation in the node for managing user.
19. The method set forth in claim 1 wherein:
the nodes include a first node of the plurality which receives the first input;
the steps of responding to the first input and sending a message to the managing user are performed in the first node; and
the step of performing the system operation in the node is performed in the node specified in the first input.
20. A memory device which is accessible to the system,
the memory device being characterized in that:
the memory device contains code which, when executed by the system, performs the method set forth in claim 1.