Abstract:
A minitype alcohol excessive warning device includes a detecting circuit consisting of a power circuit, a delay circuit, and a sensing circuit. The detecting circuit is mounted in a housing having a simple structure, thereby constructing a miniature alcohol excessive warning device. In such a manner, the minitype alcohol excessive warning device has a low cost, can be used easily and conveniently, and is portable.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a minitype alcohol excessive warning device. 
     2. Description of the Related Prior Art 
     A conventional alcoholic concentration detecting device includes precise components to detect the alcoholic concentration accurately. However, the conventional alcoholic concentration detecting device has a large volume with an expensive cost, so that it is unavailable to the ordinary people, thereby greatly limiting the utility of the conventional alcoholic concentration detecting device. 
     SUMMARY OF THE INVENTION 
     The primary objective of the present invention is to provide a minitype alcohol excessive warning device which has a low cost, can be used easily and conveniently, and is portable. 
     In accordance with the present invention, there is provided a minitype alcohol excessive warning device comprising a housing, and a detecting circuit; 
     wherein, the housing contains a receiving space therein, and has an outer periphery formed with a plurality of detecting openings communicating with the receiving space, the detecting circuit is mounted in the receiving space of the housing, and includes a sensor mating with the detecting openings, the detecting circuit further includes a power supply indicating lamp, a stand-by indicating lamp, and an excess warning lamp each emitting light outward from the housing. 
     The detecting circuit includes a power circuit, a delay circuit, and a sensing circuit, wherein: 
     the power circuit includes a battery co-operating with a power switch for supplying power, and a voltage decrease resistor serially connected with the power supply indicating lamp for indicating a power connection; 
     the delay circuit includes a first comparator, a delay resistor, a delay capacitor, a first signal detecting resistor, and the stand-by indicating lamp, the first comparator includes a negative input side that can obtain an input signal through the first signal detecting resistor, a positive input side connected to the delay resistor and the delay capacitor, and an output side connected to the stand-by indicating lamp, such that after the detecting circuit has been energized by the battery, the stand-by indicating lamp can be delayed to light during a predetermined period of time; 
     the sensing circuit includes a second comparator, a second signal detecting resistor, the sensor, an adjustable resistor, a mating resistor, and the excess warning lamp, wherein the second comparator includes a positive input side that can obtain an input signal through the second signal detecting resistor, a negative input side connected to the sensor and the adjustable resistor to obtain a detecting signal, and an output side connected to the excess warning lamp, the sensor has a first end connected to a power supply and a second end connected to the mating resistor to obtain an electric power, and the adjustable resistor is variable to preset an operation basis value of the second comparator. 
     Further benefits; and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front plan schematic view of a minitype alcohol excessive warning device in accordance with the present invention; 
     FIG. 2 is a side plan view of the minitype alcohol excessive warning device as shown in FIG. 1; 
     FIG. 3 is a circuit diagram of the minitype alcohol excessive warning device as shown in FIG. 1; and 
     FIG. 4 is a flow chart of the minitype alcohol excessive warning device as shown in FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to FIGS. 1-3, a minitype alcohol excessive warning device in accordance with the present invention comprises a housing  10 , and a detecting circuit. 
     The housing  10  is constructed by two shells  101 , thereby forming a receiving space therein. The housing  10  has an outer periphery formed with a plurality of detecting openings  11  communicating with the receiving space. Each detecting opening  11  is extended through the two sides of the housing  10  as shown in FIG.  2 . Preferably, the housing  10  is a light permeable housing. 
     As shown in FIG. 3, the detecting circuit includes a power circuit  20 , a delay circuit  30 , and a sensing circuit  40 . 
     The power circuit  20  includes a battery  21  co-operating with a power switch  22  for supplying the electric power to the detecting circuit. The power switch  22  includes a control connection point  221 , a close connection point  222 , and an open connection point  223 . When the control connection point  221  is connected with the close connection point  222 , the detecting circuit is connected with and energized by the power supply of the battery  21 . When the control connection point  221  is connected with the open connection point  223 , the detecting circuit is disconnected with the power supply of the battery  21 . A voltage decrease resistor  23  is mounted on a line connected to the control connection point  221 , and is serially connected with a power supply indicating lamp  24  for indicating that the power supply is disposed at connection state. The power supply indicating lamp  24  may be formed by a green LED, and may emit the light outward from the housing  10 . 
     The delay circuit  30  includes a comparator  31 , a delay resistor  32 , a delay capacitor  33 , a signal detecting resistor  34 , and a stand-by indicating lamp  35 . The stand-by indicating lamp  35  may be formed by a yellow LED. The comparator  31  includes a negative input side  312  that can obtain an input signal (obtain the basis,, signal from the power supply) through the signal detecting resistor  34 , a positive input side  311  connected to the delay resistor  32  and the delay capacitor  33 , and an output side  313  connected to the stand-by indicating lamp  35 . The delay resistor  32  and the delay capacitor  33  of the delay circuit  30  have a lime constant RC representing a delay time which may be equal to ten seconds (in the preferred embodiment) by changing the value of the delay resistor  32  and the value of the delay capacitor  33 . Thus, after the detecting circuit has been energized by the battery  21 , the stand-by indicating lamp  35  can be delayed to emit light during a predetermined period of time, e.g., ten seconds (in practice, the pre-heating time required for the sensor is from five to eight seconds). The stand-by indicating lamp  35  may emit light outward from the housing  10 . 
     The sensing circuit  40  includes a comparator  41 , a signal detecting resistor  42 , a sensor  43 , an adjustable resistor  44 , a mating resistor  45 , and an excess warning lamp  46 . The excess warning lamp  46  may be formed by a red LED. The comparator  41  includes a positive input side  411  that can obtain an input signal through the signal detecting resistor  42  (obtain the basis signal from the power supply), a negative input side  412  connected to the sensor  43  and the adjustable resistor  44  to obtain a detecting signal, and an output side  413  connected to the excess warning lamp  46 . The sensor  43  has a first end connected to the power supply and a second end connected to the mating resistor  45  to obtain the electric power. The excess warning lamp  46  may emit light outward from the housing  10 . The sensor  43  is mounted in the housing  10  to mate with the detecting openings  11 . The adjustable resistor  44  is variable to preset the operation basis value of the comparator  41 . The sensing circuit  40  has an alcohol concentration detection basis value which may be preset by changing the value of the adjustable resistor  44 . In the preferred embodiment, the alcohol concentration detection basis value may be preset to be equal to 0.25 mg/l. 
     In the present invention, the sensor  43  can be used to detect the tiny particles in the gas. Sensors of different features can be used to detect different kinds of gases, such as sulphide, carbon monoxide, carbon dioxide, carbide or the like. The sensor  43  can convert the detecting results into the resistance values. In use, the sensor  43  has to be preheated during a predetermined period of time before detection. In the preferred embodiment, the pre-heated time required for the sensor  43  is from five to eight seconds. When air containing alcoholic tiny particles passes through the sensor  43 , the resistance value of the sensor  43  is decreased. In practice, the concentration of the alcoholic tiny particles is inversely proportional to the resistance value of the sensor  43 . Thus, if the alcoholic concentration is increased, the resistance value of the sensor  43  is decreased. 
     Referring to FIG. 4, the power switch  22  is switched to the “ON” position, whereby the control connection point  221  is connected with the close connection point  222 , so that the detecting circuit may be connected with and energized by the power supply of the battery  21 . At the same time, the green light of the power supply indicating lamp  24  lights. The delay resistor  32  of the delay circuit  30  co-operates with the delay capacitor  33  to proceed the charging and discharging action simultaneously, and then to transmit the signal to the comparator  31  to be output, so that the yellow light of the stand-by indicating lamp  35  may light during ten seconds by changing the value of the delay resistor  32  and the value of the delay capacitor  33 . At the same time, the sensor  43  is energized and heated during five to eight seconds, until the stand-by indicating lamp  35  turns off (after ten seconds). Thus, pre-heated process of the sensor  43  is complete, and the sensor  43  is ready for detection. 
     In use, the user may blow air toward the detecting openings  11  of the housing  10 . The resistance value of the sensor  43  will change if the airflow contains the alcoholic tiny particles. In the preferred embodiment, the alcohol concentration detection basis value may be preset to 0.25 mg/l by changing the value of the adjustable resistor. When the alcohol concentration contained in the airflow exceeds the basis value, the resistance value of the sensor  43  is very low, so that the comparator  41  of the sensing circuit  40  is operated, so as to drive the red light of the excess warning lamp  46  to light. When the alcohol concentration contained in the airflow is lower than the basis value, the resistance value of the sensor  43  is very high, so that the excess warning lamp  46  is not operated. The power switch  22  may be switched to the “OFF” position after the detection process, whereby the control connection point  221  is disconnected with the close connection point  222 , so that the detecting circuit stops operation. 
     Accordingly, the circuit volume of the present invention may be designed to have a very small status, thereby facilitating the user carrying the minitype alcohol excessive warning device. As shown in FIG. 1, the minitype alcohol excessive warning device may be attached to a key ring  50 . In addition, the cost is very low. When the power switch  22  is opened, the power supply indicating lamp  24  normally lights for providing an illuminant effect. It is appreciated that the lighting time of the excess warning lamp  46  is proportional to the amount of the airflow blown by the user. The excess warning lamp  46  will light if the alcohol concentration contained in the airflow exceeds the basis value of 0.25 mg/l. The lighting time of the excess warning lamp  46  is short if the amount of the airflow blown by the user is little, and the lighting time of the excess warning lamp  46  is longer if the amount of the airflow blown by the user is more, thereby preventing the person to be detected from blowing little amount of airflow. 
     While the preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that various modifications may be made in the embodiment without departing from the spirit of the present invention. Such modifications are all within the scope of the present invention.