| 摘要 |
PURPOSE:To improve the accuracy of detection of an angle by using an infrared ray emitting element and a photo transistor (TR). CONSTITUTION:The infrared ray emitting element 5 and the photo TR6 are fitted to the lower part of a dial pulley 3 turning a variable capacitor 7. Then, a dial pulley side is provided with a reflecting section 4 to which an infrared ray is reflected and an infrared ray transmitting section. The set frequency is made disabled for receiving by turning off an output of a radio circuit when the photo TR6 receives the infrared ray. Thus, a definite angle of a pulley is detected instantly because of the infrared ray and the receiving of only a limited frequency band in a received frequency width is disabled surely. |
