| 摘要 |
PURPOSE:To enable privacy communication capable of obtaining many keycodes by scrambling the BBD delay circuit clock which can transmit voice after changing Y frequency by VCO. CONSTITUTION:Voice input In is transmitted into the BBD delay circuit 1. The BBD delay circuit 1 is controlled by clock pulse from VCO 2. Output of VCO 2 is counted by the counter 3 and the counted output is impressed to a level regulating circuit 4 of an oscillating control voltage of the VCO 2. Combinations of VCO output frequency allow many keycodes to be obtained. This secures call content from a leak and enhances scrambling effect. |
