公开(公告)号：US4401977A

公开(公告)日：1983-08-30

申请号：US222942

申请日：1981-01-06

Applicant: Derek R. Taylor

Inventor： Derek R. Taylor

IPC: G07C9/00 ,  H04B1/04 ,  H03K3/66

CPC classification number: G07C9/00111 ,  H04B1/04

Abstract: This radio transmitter is for use in an access control system and comprises a hands-free pocket token arranged to transmit bursts of oscillations at a preset carrier frequency with a preset number of carrier frequency cycles in each burst. The transmitter is controlled by a logic circuit driven from a counter of the number of oscillations both in a transmission burst and in the interval between bursts, so that a particularly simple system is provided which can be easily reset in accordance with requirements.

Abstract translation: 该无线电发射机用于访问控制系统，并且包括免提口袋令牌，其设置成以预设载波频率以每个突发中的预设数量的载波频率周期传送脉冲串。 发射机由在传输脉冲串和脉冲串之间的间隔中的振荡次数的计数器驱动的逻辑电路控制，使得提供可以根据需要容易地复位的特别简单的系统。