18 Haziran 2010 Cuma

Malzeme Listesi


R1_____________10K   1/4W Resistor
R2,R9,R10_____100K   1/4W Resistors
R3-R8,R11-R16__10R   1/4W Resistors
R17___________150R   1/4W Resistor
 
C1______________1µF  63V Polyester Capacitor
C2_____________10nF  63V Polyester Capacitor
C3____________100µF  25V Electrolytic Capacitor
 
D1-D13_____Red LEDs  5mm. or bigger, high efficiency
 
IC1,IC2________7555  or TS555CN CMos Timer IC
 
SW1____________SPST  Slider Switch
 
B1_______________3V  Battery (2 AA 1.5V Cells in series)


Device purpose:

This circuit has been designed to provide a clearly visible light, formed by 13 high efficiency flashing LEDs arranged in a pseudo-rotating order. Due to low voltage, low drain battery operation and small size, the device is suitable for mounting on bicycles as a back light, or to put on by jogger/walkers.


Circuit operation:

IC1 is a CMos version of the 555 IC wired as an astable multivibrator generating a 50% duty-cycle square wave at about 4Hz frequency. At 3V supply, 555 output (pin 3) sinking current operation is far better than sourcing, then LEDs D1-D6 are connected to the positive supply rail. In order to obtain an alternate flashing operation, a second 555 IC is provided, acting as a trigger plus inverter and driving LEDs D7-D12. D13 is permanently on.
The LEDs are arranged in a two series display as shown below, with a center LED permanently on. This arrangement and the alternate flashing of the two series of LEDs provide a pseudo-rotating appearance.


LED düzenleme:




Not :





  • Yanıp sönen ledlerin frekansını C1 in değerini değiştirerek elde ederiz



  • Yüksek verimli LED'ler gereklidir.



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    İzleyiciler

    LED DİRENÇ HESAPLAMA

    All LEDs require current limiting, without a current limiting mechanism the LED will usually burn out in under a second. Adding a simple resistor is the easiest way to limit the current. Use the calculator below to find out the value of resistor you require.

    For example if you are wanting to power one of our_blank">red LEDs in an automotive application you would see that the typical forward voltage is 2.0 Volts and the maximum continuous forward current is 30mA. Therefore you would enter 14.5, 2.0 and 30 into the Single LED calculation box. After calculating you get 470ohm 1 watt as the result. Here is a that allows you to enter a resistor value and generate the corresponding color code.

    Note: For automotive applications use the actual system voltage, not 12 Volts. Most 12 Volt system actually operate at around 14.5 Volts.

    Supply Voltage
    VOLTS
    Voltage Drop Across LED
    VOLTS
    Desired LED Current
    MILLIAMPS



    Calculated Limiting Resistor
    OHMS
    Nearest higher rated 10% resistor

    Calculated Resistor Wattage
    WATTS
    Safe pick is a resistor with
    power rating of (common values are .25W, .5W, and 1W)
    WATTS

    LEDs in series

    Several leds in series with one resistor
    Supply Voltage
    VOLTS
    Voltage Drop Across LED
    VOLTS
    Desired LED Current
    MILLIAMPS
    How many LEDs connected




    Calculated Limiting Resistor
    OHMS
    Nearest higher rated 10% resistor

    Calculated Resistor Wattage
    WATTS
    Safe pick is a resistor with
    power rating of (common values are .25W, .5W, and 1W)
    WATTS
    LM317 UYGULAMA DEVRELERİ HESAPLAMASI

     




    Çıkış Voltajı
    R1 resistor

    R2 resistor

    R1 resistor
    R2 resistor

    Çıkış Voltajı


    Lm317 uygulama devreleri ve detayli bilgiye Buradan ulasabilirsiniz

    LM555 - ASTABLE OSCILLATOR CALCULATOR

    LM555 - ASTABLE OSCILLATOR CALCULATOR
    Value Of R1 Ohms Value Of R2 Ohms
    Value Of C1 Microfarads
    Output Time HIGH SECONDS Output Time LOW SECONDS Output Period HIGH + LOW SECONDS Output Frequency HERTZ Output Duty Cycle PERCENT
    Resistor values are in Ohms (1K = 1000) - Capacitor values are in Microfarads (1uF = 1)

    NOTE: The leakage currents of electrolytic capacitors will affect the actual output results of the timers. To compensate for leakage it is often better to use a higher value capacitor and lower value resistances in the timer circuits.

    LM555 Astable Oscillator Circuit Diagram


    LM555 - ASTABLE CAPACITOR CALCULATOR

    The next calculator can find the capacitance needed for a particular output frequency if the values of R1 and R2 are known.

    Value Of R1 Ohms Value Of R2 Ohms
    Frequency Desired Hertz
    Capacitance uF
    s

    VOLT AMPER OHM ve WATT HESAPLAMA

    Current:
    kA (kiloamps) A (amps) mA (milliamps) µA (microamps)
    Voltage:
    kV (kilovolts) V (volts) mV (millivolts) µV (microvolts)