3 Simple Camera Flasher Circuit


This simple camera flasher is one of the uses of joule thief circuit (See sample project in joule thief).  The 3V battery voltage is step up to around 400V by transformer T1. Diode D will rectify the voltage to DC and capacitor C2 and C3 store the energy. Neon lamp will indicate that C3 has enough charge. When  PB is pushed, the voltage stored in capacitor C2 is step up to several thousands of volts that will trigger the xenon to light up.
Camera Flasher schematic diagram
Part List:
R1 - 560 ohms 1/2W
R2 - 2.7 Mega ohms 1/4W
R3 - 20 Mega ohms 1/4W
C1 - 100nF
C2 - 220uF electrolytic capacitor rated 350V and above
C3 - 2.2uF electrolytic capacitor rated 350V and above
T1 - small center-tapped transformer with ratio at least 35 turns ratio
     (S/P = 35 or more)  or see transformer construction in 3V stun gun
T2 - small transformer with ratio at least 20 turns ratio
    (Secondary turn Sx / Primary turn Px = 20 or more)
D - 1N4007 or similar diode
Neon - Neon lamp indicator
Q - TIP31C, TIP41c or similar
Flash - Xenon flash
Pb - normally open (N.O.) push button
Bat - 3v or two AA battery

3 comments:

  1. Hi,
    Can this circuit be used in lighting a CFL lamp ?
    warm regards

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  2. Hi,
    Can this circuit be used in lighting a CFL lamp ?
    warm regards

    ReplyDelete
  3. I wouldn’t recommend it as its supply is only 3v. The circuit draws a relatively large current initially to charge C2 but after that it only trickle charges C2 until the Pb switch is pressed and C2 is discharged, then the charge process begins again.
    Florescent inverters draw a constant current of around 250mA from the supply. Drawing that current from these batteries would discharge them very quickly.

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