Current regulated LED strobe drive circuit

Patent metadata

Field	Value
Publication number	US-9345082-B2
Application number	US-201414315721-A
Country	US
Kind code	B2
Filing date	Jun 26, 2014
Priority date	Jun 18, 2012
Publication date	May 17, 2016
Grant date	May 17, 2016

Abstract

A current regulating LED strobe drive circuit including an energy storage component, a current regulator electrically coupled to the energy storage component for sensing and regulating a current supplied by the energy storage element, a LED electrically coupled to the current regulator, a flash control element electrically coupled to the current regulator for generating a flash pulse signal that dictates a pulsed pattern with which current is allowed to flow from the current regulator to the LED, an output control having an operator interface for allowing an operator to select a desired light output level, wherein the output control is electrically coupled to the current regulator for varying the amount of current supplied to the LED, and an inrush control including a plurality of slow charge circuits, wherein each slow charge circuit is configured to provide a respective peak current for charging the energy storage component.

First claim

The invention claimed is:

1. A variable output LED strobe drive circuit comprising:
an energy storage component;
a current regulator electrically coupled to the energy storage component for sensing and regulating a current supplied by the energy storage element;
a LED electrically coupled to the current regulator;
a flash control element electrically coupled to the current regulator for generating a flash pulse signal that dictates a pulsed pattern with which current is allowed to flow from the current regulator to the LED;
an output control having an operator interface for allowing an operator to select a desired light output level, wherein the output control is electrically coupled to the current regulator for varying the amount of current supplied to the LED; and
an inrush control including a plurality of slow charge circuits, wherein each slow charge circuit is configured to provide a respective peak current for charging the energy storage component by an amount that corresponds to the operator-selected light output level.

2. The drive circuit of claim 1 , wherein the current regulator comprises a current sensing component and a control device coupled to the current sensing component and to the LED for delivering current to the LED in response to the sensed current.

3. The drive circuit of claim 1 , further comprising a filter component electrically coupled to the current regulator for filtering an amount of electrical signal noise produced by the current regulator.

4. The drive circuit of claim 1 , wherein the light output control is electrically coupled to the flash control element for varying the characteristics of the flash pulse.

5. The drive circuit of claim 1 , wherein a first of the slow charge circuits has a first peak current and a second of the slow charge circuits has a second peak current, the second peak current being greater than the first peak current.

6. The drive circuit of claim 5 , wherein the first of the slow charge circuit includes a first current-limiting resistor and the second slow charge circuit incudes a second current-limiting resistor, the second current-limiting resistor having a lower rating than the first current-limiting resistor.

7. A LED strobe drive circuit comprising:
a current sensing element;
a LED electrically coupled to the current sensing element;
a current regulator electrically coupled to the current sensing element and to the LED for supplying an amount of current to the LED in response to a current sensed by the current sensing element;
a switch electrically coupled to the current regulator and to the LED for generating a flash pulse signal that dictates a pulsed pattern with which current is allowed to flow to the LED;
an output control having an operator interface for allowing an operator to select a desired light output level, wherein the output control is electrically coupled to the current regulator for varying the amount of current supplied to the LED; and
an inrush control including a plurality of slow charge circuits, wherein each slow charge circuit is configured to provide a respective peak current for charging the energy storage component by an amount that corresponds to the operator-selected light output level.

8. The drive circuit of claim 7 , wherein the current regulator comprises a control device coupled to the current sensing component and to the LED for delivering current to the LED in response to the sensed current.

9. The drive circuit of claim 7 , further comprising a filter component electrically coupled to the current regulator for filtering an amount of electrical signal noise produced by the current regulator.

10. The drive circuit of claim 7 , wherein the output control is electrically coupled to the flash control element for varying the characteristics of the flash pulse.

11. A method for driving a LED strobe comprising:
charging an energy storage element with an input current;
selecting a first light output level;
generating a pulsed electrical signal that is in part defined by the selected light output level;
allowing current to flow from the energy storage element to the LED in accordance with the pulsed electrical signal;
sensing the input current and providing a corresponding regulated current to the LED; and
recharging the energy storage element by applying the input current to a first slow charge circuit having a first peak current that corresponds to the selected first light output level.

12. The method of claim 11 , wherein charging the energy storage element comprises:
applying the input current on a slow charge line connected to the energy storage element for charging the energy storage element at a predetermined rate; and
applying the input current on a bypass control line connected to the energy storage element to fully charge the energy storage element.

13. The method of claim 11 , further comprising preventing electrical signal noise from being transmitted into NAC wiring.

14. The method of claim 11 , wherein selecting a light output level includes supplying an amount of current to the LED according to a manually set control.

15. The method of claim 11 , further comprising defining a desired light output level by varying characteristics of the pulsed electrical signal according to a manually set control.

16. The method of claim 11 , further comprising recharging the energy storage element by applying the input current to a second slow charge circuit having a second peak current that corresponds to a selected second light output level, wherein the second peak current is different from the first peak current and the second light output level is different from the first light output level.

Assignees

• Tyco Fire & Security Gmbh

Inventors

• Savage Jr Kenneth E

Classifications

• H05B45/10 Primary

  Controlling the intensity of the light · CPC title

• H02M3/156

  with automatic control of output voltage or current, e.g. switching regulators · CPC title

• H05B45/50

  responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits · CPC title

• H05B33/0842

  Electricity · mapped topic

• Y02B20/346

  Cross-Sectional Technologies · mapped topic