Circuit arrangement, and signaling light provided with the circuit arrangement

• US 6,094,014 A
• Filed: 08/03/1998
• Issued: 07/25/2000
• Est. Priority Date: 08/01/1997
• Status: Expired due to Term

• Current Assignee: Philips Lighting North America Corporation (Signify N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Nijhof, Engbert B. G., Bucks, Marcel J. M.
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US09/128,148
• Time in Patent Office: 722 Days
• Field of Search: 315/169.3, 315/291, 315/307, 315/290, 315/287, 323/222, 323/282, 323/351, 363/15, 363/25, 363/89, 363/80, 363/81, 363/126
• US Class Current: 315/291
• CPC Class Codes: H05B 45/50 responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits

Abstract

A circuit arrangement for operating a semiconductor light source, includes input terminals for connecting a supply voltage, an input filter, a converter having a control circuit, and output terminals for connecting the semiconductor light source. The circuit arrangement is provided with a voltage detector for detecting the output voltage at the output terminals.

Claims

1. A circuit arrangement suitable for operating a semiconductor light source, said circuit arrangement comprising:

input terminals for connecting a supply voltage;

input filter means;

a converter comprising a control circuit; and

output terminals for connecting the semiconductor light source, wherein said converter generates a current for application to said semiconductor light source, and said control circuit controls said converter to produce a predetermined value of said current at said output terminals, said predetermined value of said current corresponding to an output voltage which is less than a predetermined threshold voltage,

characterized in that the circuit arrangement further comprises voltage detection means for detecting the output voltage at the output terminals, said voltage detection means generating a detection signal when the output voltage exceeds said predetermined threshold voltage.

2. A circuit arrangement as claimed in claim 1, characterized in that the input filter means includes switching means for switching the converter into an operational state in which the output voltage is made less than the threshold voltage.

3. A circuit arrangement as claimed in claim 2, characterized in that the switching means comprises disconnecting means for disconnecting the converter from said supply voltage, and the detection signal causes the converter to operate in a state such that the disconnecting means is activated.

4. A circuit arrangement as claimed in claim 3, characterized in that the disconnecting means is constructed as a fuse.

5. A circuit arrangement as claimed in claim 1, characterized in that the circuit arrangement is suitable for connection to a solid state relay, and in that a self-regulating current limitation network is connected between the input filter means and the converter.

6. A signaling light provided with a housing containing a semiconductor light source, characterized in that the signaling light is provided with a circuit arrangement for operating the semiconductor light source, said circuit arrangement comprising:

input terminals for connecting a supply voltage;

input filter means;

a converter comprising a control circuit; and

output terminals for connecting the semiconductor light source, wherein said converter generates a current for application to said semiconductor light source, and said control circuit controls said converter to produce a predetermined value of said current at said output terminals, said predetermined value of said current corresponding to an output voltage which is less than a predetermined threshold voltage,

characterized in that the circuit arrangement further comprises voltage detection means for detecting the output voltage at the output terminals, said voltage detection means generating a detection signal when the output voltage exceeds said predetermined threshold voltage.

7. A signaling light as claimed in claim 6, characterized in that the circuit arrangement is provided with a housing which is integrated with the housing of the signaling light.