JPS639164U

JPS639164U -

Info

Publication number: JPS639164U
Application number: JP1986102943U
Authority: JP
Priority date: 1986-07-03
Filing date: 1986-07-03
Publication date: 1988-01-21

Description

[Brief explanation of the drawing]

第１図は、この考案の一実施例の回路図である
。第２図は、第１図の回路のスイツチの切換タイ
ミングと流れる電流を示すタイミング図である。
第３図は、この考案の他の実施例を示す回路図で
ある。第４図は、第３図の回路のスイツチの切換
えと流れる電流とのタイミングを示す図である。
第５図は、この考案のさらに他の実施例の回路図
である。第６図は、第５図の回路のスイツチの切
換えと流れる電流との関係を示すタイミング図で
ある。第７図は、この考案のさらに他の実施例で
あり、スイツチング回路の一例を示す回路図であ
る。第８図は、第７図の回路のスイツチの切換え
と流れる電流とのタイミングを示す図である。第
９図は、従来の回路の一例を示す図である。第１
０図は、第９図の回路のスイツチの切換えと流れ
る電流との関係を示すタイミング図である。図において、１１はＬＥＤ、１２，１５，１６
はスイツチ、１３は定電流源、１４はバイパス用
負荷としてのダイオードを示す。 FIG. 1 is a circuit diagram of an embodiment of this invention. FIG. 2 is a timing diagram showing the switching timing of the switch in the circuit of FIG. 1 and the flowing current.
FIG. 3 is a circuit diagram showing another embodiment of this invention. FIG. 4 is a diagram showing the timing of switching of the switch and flowing current in the circuit of FIG. 3.
FIG. 5 is a circuit diagram of still another embodiment of this invention. FIG. 6 is a timing chart showing the relationship between the switching of the switch and the flowing current in the circuit of FIG. FIG. 7 is a circuit diagram showing an example of a switching circuit, which is still another embodiment of this invention. FIG. 8 is a diagram showing the timing of switching of the switch and flowing current in the circuit of FIG. 7. FIG. 9 is a diagram showing an example of a conventional circuit. 1st
FIG. 0 is a timing diagram showing the relationship between the switching of the switch and the flowing current in the circuit of FIG. In the figure, 11 is an LED, 12, 15, 16
13 is a constant current source, and 14 is a diode as a bypass load.

Claims

[Scope of claims for utility model registration] (1) LE used as a light source for optical application measuring instruments
A lighting control circuit for D, comprising: a constant current source for supplying a constant current to the LED; a switching means provided between the LED and the constant current source; When the current applied to the LED from the current source is cut off by the switching means, a current from a constant current source is applied instead of the LED, and a load means having a load equal to that of the LED is provided. Lighting control circuit. (2) The lighting control circuit for an LED for an optical application measuring instrument according to claim 1, wherein the load means includes a diode.