JPS6221634U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the present invention;
Figure 2 is an explanatory diagram showing the characteristics of the main parts used in the same as above;
Fig. 3 is a configuration diagram of the main parts of the same as above, Fig. 4 is an explanatory diagram of the same as the above, Fig. 5 is a circuit diagram of another embodiment of the present invention, and Fig. 6 shows the characteristics of the main parts used in the above. 7 and 8 are circuit configuration diagrams showing a conventional example, FIGS. 9 and 10 are operation explanatory diagrams of the same, and FIG. 11 is a block diagram showing a photoelectric switch using the same. Figure 12 is a circuit configuration diagram showing the same light receiving circuit as above, Figure 13 is an equivalent circuit of the circuit in Figure 12, and Figure 14 is an equivalent circuit diagram of the circuit in Figure 12.
The figure is a circuit configuration diagram showing the main parts of another conventional example, No. 15
Figures 17 to 17 are explanatory diagrams of the same operation. 1 is a light emitting element, Z is a resistance, T is a temperature, P is a light emission power, and IF is a drive current.

Claims (1)

[Scope of utility model registration request] It is used in photoelectric switches that detect objects by receiving light from a light emitting element with a light receiving element. 1. A light emitting element drive circuit comprising a circuit element having a temperature characteristic that causes a drive current flowing in the light emitting element to change exponentially with respect to temperature, which is opposite to a change in light emitting power with respect to temperature.