| 摘要 |
<p>A solid state device for generating signals in response to a flow metering device is composed of a fixed frequency signal generator periodically blocked for more then one of its oscillation periods by the output of a second signal generator composed of a light emitting diode, a phototransistor, an interposed perforated shutter disc driven by the flow metering device and suitable amplifier, in particular a Schmitt trigger circuit. This combination forms a variable increment transducer suitable for location near equipment for dispensing flammable fuilds. The output of the transducer, consisting of successive pulse trains of fixed frequency but variable length, is supplied to equipment which (a) counts the number of pulse trains to register total volume (b) limits the number of pulses in each train to a price related number and (c) counts the pulses so limited to register total price.</p> |
