| 摘要 |
<p>PURPOSE:To inform surely the clogging of a filter for a user by detecting current changes of high voltage electric source part connected to an electrode plate and moving the moving part of a luminous body or the like. CONSTITUTION:When no dust is adhered on a dust collecting part 5, a current which is flowed to a generation circuit 16 of D.C. high voltage is small and the voltage inputted to a comparator 21 is set at Vi<Vo and the current is not outputted from the comparator 21, therefore a light emission diode 24 does not turn on light. On the other hand, when the adhesion of dust on the dust collecting part 5 progresses, the resistance is lowered and the supplying current to the circuit 6 is increased, therefore the voltage inputted to the comparator 21 becomes Vi>Vo. Then, when, as a period at which the voltage becomes Vi>Vo. resistance 15, 17, 18 are set so that the clogging of the part 5 advances and about 80% clogging state is shown; the comparator 21 is turned on and a transistor 25 is turned on, therefore the diode 24 is lighted.</p> |
