| 摘要 |
<p>An instrument is used as a breathalyser. A motorist is required to blow into it in order to measure the alcohol in the body. An immediate result is obtained and enables the user to keep track of the level. A stabilised power supply circuit(10) provides a voltage which is converted (11) into an alternating voltage to heat a gas detector resistance (13). A reference circuit (12) provides a reference voltage for the detector and an amplifier (14) amplifies the detector output. A selector (15) provides a signal representing three levels of alcohol for memory circuits (16). These are resolved by logic circuits (17) to illuminate respective indicator lamps (4, 5, 6) or provide an audible signal (18).</p> |
