| 摘要 |
PURPOSE:To enable conversion to a digital vlaue, by controlling a circuit for amplifying the output of a light receiving element by the light of a light emitting element to hold a peak and a circuit for comparing the output with a function generation circuit by a microcomputer. CONSTITUTION:When a power source is closed, a microcomputer 1 sends a pulse signals (c) to a peak hold circuit 6 and sends a signal (a) to LED3. According to the change in smoke concn. (s), the circuit 6 sends the output of a wave form (d) to a comparing circuit 8 and an internal counter is cleased by a step of voltage-to-time conversion while the computer 1 inputs a signal (e) to a saw- tooth wave generation circuit 7 and further inputs a signal (f) to the comparing circuit 8. The computer 1 operates operatin processing when the input from the circuit 8 comes to a low level and, when judges that the penetration of smoke is present, transmits a relay driving signal (h) to operate an air purifier. By this method, cost can be lowered.
|
