Circuit for protecting a laser indicator
US5933441A · kind A · utility
Inventor
Key dates
| Filing date | Nov 6, 1997 |
| Grant date | Aug 3, 1999 |
| Priority date | — |
| Expiry date | Nov 6, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/222
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A circuit for protecting a laser indicator is disclosed in which a current amplifying circuit composed of two transistors drives a laser light emitting diode (LED) to generate a laser light. A base of one of the two transistors connects with a protective resistor and a variable resistor. The variable resistor is used to control the magnitude of a base current of the transistor and the protective resistor is used to prevent an overrating current. A diode is further coupled to a positive power input terminal of the current amplifying circuit to prevent the circuit for protecting a laser indicator from being damaged due to being reversely connected the polarities of the power source. Through a design of such a circuit, a stable laser light-spot is achieved and the components in the circuit will not be damaged.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.