2 Voltage Multiplier Circuit

The use of this circuit is multiply the input peak voltage twice (voltage doubler), thrice (voltage trippler) and or even much higher.
How this works:
1. During the first negative half cycle, diode D1 is on and capacitor C1 is charged to the negative peak voltage (100V) of the source. I recommend to see how the diode works.
2. During the next positive half cycle D1 is open and D2 is close and thus charging C2, making the voltage across point B (marked green) twice (200V) the peak value of the input.
3. During the next negative half cycle C3 is charged; and the next positive half C4 is charged.
4. The output voltage of the circuit below is in voltage output diagram. See the color of markings and output to make analysis easier.

voltage multiplier circuit

voltage output diagram

The circuit will work only in sinewave, square-wave or similar signals except DC. You can further increase the output voltage by just adding capacitor and diode only.

Sample projects using multiplier circuit:
Bug zapper circuit - output more than thousand of volts
Mosquito electric racket -  transforms 3V to several thousand volts.

10 Mosquito Racket Circuit

This circuit is a high voltage generator using a 3V battery. It is used as a bug or mosquito zapper and in a racket form. The circuit is composed of two main parts, the inverter and the voltage multiplier circuit. The inverter is the one responsible of converting 3V DC to 400V square wave. The inverter circuit is the Q, R, and Tr in the circuit.
Another part of the circuit is the voltage multiplier circuit which is composed of diode D and capacitor C combination. The use of this circuit is to convert the 400V square wave voltage to thousand volts DC.

3V zapper circuit

commercial mosquito racket

2N2222 and 9013 pinout

Part List:
R - 1.2 kilo ohms 1/4W
Q - 2N2222, CS9013, or higher power capacity NPN transistor
C - 100nF Mylar capacitor or any type rated 1000V minimum
D - 1N4007 or diode with minimum 1000V inverse voltage rating
Tr - See info below.
Bat - 3V battery (2 x AA cells)
Sw - preferably push button or just ordinary switch

Transformer:
You can recycle the transformer core from an old CFL. You can use any core, the toroidal or the E type ferrite core. The primary windings P1 and P2 have 15 turns of #28AWG magnetic wire each. The secondary or high voltage winding S1 is a 450 turns of #36AWG magnetic wire.

recycle the core

Note: This not a toy, do not play with it. Avoid touching the output pins since its high voltage and can give you a kick.

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

9 BUG ZAPPER CIRCUIT

Circuit  below is a simple bug zapper project using voltage multiplier circuit powered by 220v AC. This zapper circuit produces a high voltage (1200V plus) but very minimal current.  The series LED and 100nF capacitor will produce a light that will attract insects. All capacitors are of mylar or paper type.

bug zapper circuit

Part List:
C1 x 5 - 0.47uF
D1 x 5 - 1N4007 or similar
C2 - 100nF if using red LED and 220nF if white LED
LED x 6 - White LED or any color that is very attractive to insects

Warning !! : This bug zapper circuit is directly connected to ac supply and produce a very high voltage and can cause electrocution. Think of your safety before building.

24 3V electronic stun gun circuit

stun gun schematc

This circuit above is a cheap version stun gun circuit that is powered by two AA baterry. The output of this electronic project is about 350V dc.
The heart of the circuit is the oscillator that is composed of Windings and transistor.

Part List:
Transistor - Tip41 or similar
Resistor - 100-ohms 1W
Capacitor-100nF
C-1.2uF 1000V or any cap with 1000V rating
D-1N4007 diode or similar

Primary and Feedback winding

TIP41 pins

Primary winding P is composed of 16 turns of #24 AWG wire, feedback F is composed of 8 turns of #24 AWG wire, and secondary winding S is composed of 270 turns of #30 AWG magnetic wire. P1 is connected to the collector of transistor, F2 to the 100-ohms resistor at transistor base. F1 and P2 to the battery. The output of Sec winding is rectified by Diode Bridge. The output capacitor is an electrolytic type that is rated 400V above. Capacitance of the output capacitor depends on what available on hand, but always keep in mind that the higher the value the better. this simple electronic project is dangerous when accidentally touched, thus avoid holding the output and discharge the capacitor before and after using.

One of the uses of this circuit is the camera flasher circuit.