Batteryless tire inflation pressure detecting apparatus with improved power-saving configuration

摘要

A tire inflation pressure detecting apparatus includes a second transceiver provided on the body of a vehicle which changes its operation alternately between a second transmitter and a second receiver mode, thereby intermittently transmitting a radio wave. A first transceiver provided on a wheel of the vehicle operates in a first receiver mode to receive the radio wave, thereby charging a charging unit. When the charging unit has been sufficiently charged, the first transceiver changes operation thereof from the first receiver mode to a first transmitter mode, in which the first transceiver first repeatedly transmits an informing signal at predetermined time intervals for a predetermined time period and then transmits a pressure signal. When the informing signal is received by the second transceiver in the second receiver mode, the second transceiver keeps its operation in the second receiver mode until the pressure signal is completely received.