These circuits is used to control audio with light. In simple transduction And the change of light. To control the tone.,we is recommended that three circuits, each circuits consists of a simple device. Suitable for studying the performance of optical sensors is LDR.
This the Tone Generator circuit that interesting because of can control the sound has with the light. By use the integrated circuit NE555 be pillar equipment , which perform produce sound frequency in model Astable Multi vibrator or pulse generator. And use 25 ohm small-sized loudspeakers. For the equipment detects the light. I uses LDR because of be usable good easy and economize with. For tone sound use can fine C1 get. by many values , make the low voice but when the value is a little make tall sound goes up. The detail is other see in the circuit better.