Hairdryer including a safety device

Abstract

A hairdryer including a safety device is characterized in that the safety device is designed for detecting a jamming, even partial, of the hairdryer air suction fan.

1 . A hairdryer including a safety device, characterized in that said safety device is adapted to detect a clogging, even partial, of a filter applied to the hairdryer fan air inlet. 
   
   
       2 . A hairdryer, according to  claim 1 , characterized in that said safety device comprises a photosensor adapted to detect the light passing through the filter. 
   
   
       3 . A hairdryer, according to  claim 1 , characterized in that, as the light amount decreases because a clogging of the filter, jammed by dirty, said sensor will send a signal which, through an electronic circuit, will operate a signaling means. 
   
   
       4 . A hairdryer, according to  claim 1 , characterized in that said signaling means comprise a light indicating element which is switched on either with an intermittent or continuous light. 
   
   
       5 . A hairdryer, according to  claim 1 , characterized in that said hairdryer comprises a moisture sensor driven by said electronic circuit. 
   
   
       6 . A hairdryer, according to  claim 1 , characterized in that said filter comprises a filter mesh screen made of a processed metal, plastic material or TNT. 
   
   
       7 . A hairdryer, according to  claim 1 , characterized in that said photosensor is arranged in a rear portion of the body of the hairdryer and under the suction filter. 
   
   
       8 . A hairdryer, according to  claim 1 , characterized in that said hairdryer comprises a signaling light indicating element arranged on the body of the hairdryer, and being visible from the outside of said body. 
   
   
       9 . A hairdryer, according to  claim 1 , characterized in that said hairdryer comprises an electronic control circuit, which can be arranged at any region of the hairdryer. 
   
   
       10 . A hairdryer, according to  claim 1 , characterized in that, as a clogging, even partial, of the fan air inlet filter is detected, said safety device automatically causes said hairdryer to be switched off. 
   
   
       11 . A hairdryer, according to  claim 1 , characterized in that said safety device comprises an environment light detector allowing said safety device to properly operate even if the environment light is changed. 
   
   
       12 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises an electronic card including a single surface printed board thereon are mounted the components necessary for operating said electronic circuit, a phototransistor, a photoresistor and a power supply being arranged outside thereof. 
   
   
       13 . A hairdryer, according to  claim 1 , characterized in that said phototransistor, as suitably arranged, reads out the light amount passing through the mechanical filter of said hairdryer; said photoresistor, arranged at a different position than that of said phototransistor, reads out the environment light amount; the light amount being read by said phototransistor defining a condition of clean filter or dirty filter and, more precisely, beyond a value x, said filter being considered as dirty or clogged; the light amount read out by said photoresistor defining the environment light amount and, depending on this value, being performed a feedback to the value read out by the phototransistor, by proportionately translating the dirty filter values. 
   
   
       14 . A hairdryer, according to  claim 1 , characterized in that said card comprises thereon a red color LED; said red color LED being held in a switched off condition if said filter is clean; said red color LED being switched on only if the card is power supplied and only as the filter is considered as dirty; as the card is powered down, said LED being switched off and as it is switched on again, the light amounts on said photodetectors being read-out again and being actuated said red LED depending on this read-out. 
   
   
       15 . A hairdryer, according to  claim 1 , characterized in that said card is powered up simultaneously with said fan motor, the amount of light both on said phototransistor and on said photoresistor being controlled and the card operating as indicated up to its power down; the photodetectors being read out after about a second from the card power up, to allow the signals to be stabilized, and the following read-outs being performed repeatedly at even intervals up to the power down of the card. 
   
   
       16 . A hairdryer, according to  claim 1 , characterized in that a dirty filter signal is considered as valid only after some consecutive seconds providing the same results; the same thing occurring for the clean filter signal, thereby preventing false read-outs due to noises from occurring. 
   
   
       17 . A hairdryer, according to  claim 1 , characterized in that, as a dirty filter condition is detected, said red LED is switched on and being switched off if a new clean filter condition is detected, by the mode of operation as disclosed or as said card is switched off. 
   
   
       18 . A hairdryer, according to  claim 1 , characterized in that all the components of the electronic circuit arranged downstream of the power supply operate on a low voltage obtained by a starting middle voltage V.110÷250 ac a low voltage. 
   
   
       19 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises a resistor Ri operating for providing a potential difference at the ends thereof to provide a low voltage due to a resistive drop, the high value of this component and its dissipated power operating to block the surge type of noises which can arrive at the power supply and cause the electronic card to fail. 
   
   
       20 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises a diode bridge designed for modifying the voltage wave shape from an alternating one with a position half wave and a negative half wave inside a fiftieth of seconds to two positive half waves inside a fiftieth second. 
   
   
       21 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises a zener diode for stabilizing the voltage to a value of 5.1V. 
   
   
       22 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises an electrolytic capacitor operating to filter said voltage and transform it from a pulse voltage to a continuous or DC voltage. 
   
   
       23 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises a resistor for quickly discharging the energy stored by said capacitor, as the power supply voltage fails; this operation being required by the microprocessor reset circuit to operate in a proper time and manner, while allowing a proper resetting and performing of the program instructions, as the power supply voltage is reset. 
   
   
       24 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises a filter ceramics capacitor arranged near the power supply pins of the microprocessor, and operating to increase the burst type of noise immunity. 
   
   
       25 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises an electronic circuit branch operating to read-out, through a microprocessor analogic digital input, the signal sent by said phototransistor; said signal changing its level depending on the light amount impinging on said phototransistor, thereby increasing or decreasing the conductivity of said phototransistor toward the ground; the fixed reference to +5 being obtained through the resistor R 4 ; the variable reference being just provided by said phototransistor. 
   
   
       26 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises an electronic circuit branch operating to read-out, through a microprocessor analogic digital input, the signal sent by said photoresistor; said signal changing its level depending on the light amount impinging on said photoresistor thereby increasing or decreasing the resistive value thereof toward the ground; the fixed reference at +5 being achieved through the resistor R 6 ; the variable reference being just achieved by the photoresistor. 
   
   
       27 . A hairdryer, according to  claim 1 , characterized in that said microprocessor, through an output pin thereof, enables the switching on or switching off of said red color LED diode DL 1 ; the current being limited by the series resistor R 3 . 
   
   
       28 . A hairdryer, according to  claim 1 , characterized in that said electronic circuit comprises a flash type of microprocessor, the core of the system, with an on-board software for operating said electronic card; in addition to the power supply being used only other three pins, two as inlet pins and one as outlet pin; said microprocessor operating at 4 Mhz and including an inner oscillator and brown-out.