Abstract:
Pulse type activating system for power supply, composed of a boosting circuit, a pulse width modulating (PWM) circuit, a sine-wave generating circuit, an MOSFET output circuit, an analog-to-digital converting circuit (ADC), a temperature sensing circuit, an overload detecting circuit, a short circuit detecting circuit, a warning circuit and a CPU. The CPU collectively controls the above circuits and in the instant of activation of the load, the CPU provides intermittent high voltage for shortening the activation time of the load. The CPU also provides protection effect for the load.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a pulse type activating system for power supply, in which a CPU collectively controls respective circuits and provides intermittent high voltage for shortening the activation time of the load. The pulse type activation system is especially applicable to those heavy tools necessitating great current and great voltage. 
     When activating a general electric appliance, the instantaneous activating current is very great. With 100 watt electric appliance exemplified, the instantaneous activating current is over 2-3 times higher than the original current. The instantaneous great current is extremely apt to damage the circuit of the electric appliance itself. A general DC-to-AC power supply is unable to provide sufficient high surge so that the ability in activating the electric appliance is affected. FIG. 1 shows a current versus time (A-T) curvature of a conventional power supply. It can be known from the diagram that for making the current reach the high surge point, a time period T x  is cost. During T x , the load is repeatedly activated. After the load is warmed up, the amount of the activation current is time by time accumulated until the activation current is able to activate the load. Furthermore, when the activation current is close to the high surge point, sometimes the load will misjudge and shut down due to overload. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a pulse type activating system for power supply, in which a CPU collectively controls respective circuits. 
     It is a further object of the present invention to provide the above pulse type activating system for power supply, which is able to quickly activate a load. 
     It is still a further object of the present invention to provide the above pulse type activating system for power supply, which is able to protect the circuit of the load. 
     According to the above objects, the pulse type activating system for power supply of the present invention is composed of a boosting circuit, a pulse width modulating (PWM) circuit, a sine-wave generating circuit, an MOSFET output circuit, an analog-to-digital converting circuit (ADC), a temperature sensing circuit, an overload detecting circuit, a short circuit detecting circuit, a warning circuit and a CPU. The boosting circuit is connected with the pulse width modulating (PWM) circuit. The output end of the boosting circuit is connected with the MOSFET output circuit. The sine-wave generating circuit is connected with the MOSFET output circuit. The MOSFET output circuit is connected with both the overload detecting circuit and the short circuit detecting circuit. The CPU is connected with the pulse width modulating (PWM) circuit, the sine-wave generating circuit, the temperature sensing circuit, the overload detecting circuit, the short circuit detecting circuit, the analog-to-digital converting circuit (ADC) and the warning circuit. The CPU collectively controls the above circuits and in the instant of activation of the load, the CPU provides intermittent high voltage for shortening the activation time of the load. The CPU also provides protection effect for the load. 
    
    
     The present invention can be best understood through the following description and accompanying drawings wherein: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a time versus current curvature diagram of a conventional power supply; 
     FIG. 2 is a block flow chart of the present invention; 
     FIG. 3 is a complete circuit diagram of the present invention; 
     FIG. 4 is a circuit diagram of the boosting circuit of the present invention; 
     FIG. 5 is a circuit diagram of the pulse width modulating (PWM) circuit of the present invention; 
     FIG. 6 is a circuit diagram of the sine-wave generating circuit of the present invention; 
     FIG. 7 is a circuit diagram of the MOSFET output circuit of the present invention; 
     FIG. 8 is a circuit diagram of the temperature sensing circuit of the present invention; 
     FIG. 9 is a circuit diagram of the overload detecting circuit of the present invention; 
     FIG. 10 is a circuit diagram of the short circuit detecting circuit of the present invention; 
     FIG. 11 is a circuit diagram of the analog-to-digital circuit (ADC) of the present invention; 
     FIG. 12 is a circuit diagram of the warning circuit of the present invention; and 
     FIG. 13 is a time versus voltage curvature diagram of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Please refer to FIG.  3 . The present invention includes CPU 1 , boosting circuit  2 , pulse width modulating (PWM) circuit  3 , sine-wave generating circuit  4 , MOSFET output circuit  5 , temperature sensing circuit  6 , overload detecting circuit  7 , short circuit detecting circuit  8 , analog-to-digital converting circuit (ADC)  9  and warning circuit  10 . 
     The boosting circuit  2  boosts the input low DC voltage into high DC voltage. 
     The pulse width modulating (PWM) circuit  3  serves to modulate the frequency width provided by CPU 1 . 
     The sine-wave generating circuit  4  serves to modulate the frequency provided by CPU 1  to generate sine-wave with suitable amplitude. 
     The MOSFET output circuit  5  serves to combine high voltage with suitable frequency width and sine-wave with suitable amplitude to output all-bridge intermittent high voltage pulse. 
     The temperature sensing circuit  6  serves to detect whether the temperature is too high. 
     The overload detecting circuit  7  serves to detect overload. 
     The short circuit detecting circuit  8  serves to detect whether the respective circuits function normally. 
     The analog-to-digital converting circuit (ADC)  9  serves to convert analog signal into digital signal easy to identify. 
     The warning circuit  10  sends out a warning in the case that the detecting circuits detect abnormal function. 
     As shown in FIG. 2, the analog-to-digital converting circuit (ADC)  9 , the temperature sensing circuit  6 , the overload detecting circuit  7 , the short circuit detecting circuit  8 , the warning circuit  10 , the pulse width modulating (PWM) circuit  3  and the sine-wave generating circuit  4  are all connected to CPU 1 . The pulse width modulating (PWM) circuit  3  is connected with the boosting circuit  2 . The boosting circuit  2  and the sine-wave generating circuit  4  are further connected with the MOSFET output circuit  5 . The MOSFET output circuit  5  is connected with both the overload detecting circuit  7  and the short circuit detecting circuit  8 . CPU 1  collectively controls the above circuits. When activated, CPU 1  respectively provides signals to the pulse width modulating (PWM) circuit  3  and the sine-wave generating circuit  4 . The pulse width modulating (PWM) circuit  3  modulates the frequency provided by CPU 1  into a suitable frequency width which enters the boosting circuit  2 . The DC is boosted by the boosting circuit  2  and the low DC voltage of the cell is boosted into high voltage with bandwidth. It is also connected to the analog-to-digital converting circuit (ADC)  9 , whereby the analog signal is converted into digital signal easy to identify. At the same time, the signal together with the sine-wave with suitable amplitude generated by the sine-wave generating circuit  4  drives the all-bridge MOSFET output circuit  5  to obtain an intermittent pulse with extremely high voltage. The MOSFET output circuit  5  is also connected with the overload detecting circuit  7  and the short circuit detecting circuit  8 . In case the output exceeds the load or a short circuit takes place, the warning circuit  10  sends out a warning signal in time. In addition, CPU 1  is connected with the temperature sensing circuit  6 , whereby in the case of abnormal temperature of the entire circuit, the warning circuit  10  also sends out a warning signal. 
     FIGS. 4 to  12  show the components of the respective circuits of the present invention in detail. 
     The boosting circuit  1  is composed of five resistors, three capacitors, four diodes, four metal-oxide-semiconductor field effect transistors and a transformer  20 . The boosting circuit  1  serves to boost the input low DC voltage into high DC voltage. 
     The pulse width modulating (PWM) circuit  3  is composed of eight resistors, four capacitors, four diodes and six transistors. CPU 1  provides a frequency signal for this circuit to generate a wave form with suitable frequency width. The wave form enters the boosting circuit, whereby the boosted high voltage carries the wave form. 
     The sine-wave generating circuit  4  is composed of two transistors and six resistors. The sine-wave generating circuit  4  oscillates the frequency provided by CPU 1  into sine-wave signal with identical frequency but different amplitude. 
     The MOSFET output circuit  5  is composed of four metal-oxide-semiconductor field effect transistors, ten resistors, four diodes, two capacitors, three Zener diodes, two transistors and a thermosensitive resistor. The sine-wave generating circuit  4  and the boosting circuit  2  input signal to the all-bridge metal-oxide-semiconductor field effect transistors which combine the PWM wave carrying great DC voltage with the sine-wave and output the wave. The output end  5  can output evenly intermittent electric pulse with high voltage. 
     The temperature sensing circuit  6  is composed of five resistors, a thermosensitive resistor  61  and an OPA operation amplifier  60 . It is connected with CPU 1  to monitor and control the temperature of the entire circuit. In case of abnormal temperature, CPU 1  does not work and the warning circuit  10  sends out the warning. 
     The overload detecting circuit  7  is composed of four resistors, a capacitor, a diode and a transistor  70  and is connected with the MOSFET output circuit  5  and the CPU 1 . In case of output overload of the output end, the CPU 1  does not work and the warning circuit  10  sends out the warning. 
     The short circuit detecting circuit  8  is composed of a resistor, two capacitors and a transistor  80  and is connected with the MOSFET output circuit  5  and the CPU 1 . In case of short circuit, the CPU 1  does not work and the warning circuit  10  sends out the warning. 
     The analog-to-digital converting circuit (ADC)  9  is composed of six resistors, a diode, two capacitors and a comparator  90 , serving to convert the analog signal of the circuit into digital signal easy to identify. 
     The warning circuit  10  is composed of two resistors, a capacitor, a diode, a transistor and a BZ 1  buzzer  11 . In the case that the any of the above detecting circuits detects abnormal signal, the CPU 1  drives the warning circuit  10 , making the buzzer  11  emit warning sound. 
     The present invention is used to activate any kind of heavy tool. In the case that the heavy tool cannot be activated at the first time, the CPU 1  informs the respective circuits to start working. As shown in FIG. 13, the output voltage of the output end  50  can in very short time T 1  provides a pulse voltage greater than the activation voltage V x . The peak value V y  of the pulse voltage is much higher than V x  so as to at one time quickly activate the heavy tool. In case the first pulse voltage still cannot activate the heavy tool, there are successive second, third, . . . , Nth pulse voltage until the heavy tool is activated. 
     In conclusion, the CPU of the present invention collectively controls the pulse width modulating (PWM) circuit, boosting circuit, sine-wave generating circuit and the all-bridge MOSFET output circuit to output signal. Also, the cooperative temperature sensing circuit, overload detecting circuit, short circuit detecting circuit and warning circuit serve to truly and effectively control the circuits. The DC voltage is converted into intermittent pulse voltage having a peak value much higher than the activation voltage. Therefore, the present invention not only is able to quickly activate the heavy tools, but also is able to protect the heavy tools. 
     The above embodiment is only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiment can be made without departing from the spirit of the present invention.