High voltage generator

The relay can be replaced by a MOSFET (IRF520) it can be used for very high frequency switching.
In the case of the relay the relay contact switches get hot enough to destroy it so can be used only for a short period of time.

Insect Repellant

Notes:
Repell those repugnent insects from your Garden this Summer with this insect repellant circuit. Designed by krishna kumar the circuitry consists of a phase locked loop (CMOS 4047) wired as a 22KHz oscillator. The output is amplified by a pair of complimentary output transistors and drives a Motorola 3.25 inch Piezo. Current drain is around 120mA so an external power supply is recommended.

The piezo used was a standard 85mm square Motorola Horn, Maplin part number WF09K or WF55K. These are rated +/-3dB to 28kHz.

A Transistor Driven Flyback Transformer

Flybacktransformer

Any Lot of TV can be used we can use any 2 sets of winding as primary
Transistors
2N3773 NPN 140V 16A Works OK, typical output of 7,000V
NTE284 NPN 180V 16A Works great, typical output of 18,000V
KSE13009 NPN 300V 12A From Fairchild, works grrrrreat!!!
MJE13009 NPN 400V 12A from ON Semiconductors, seems to work well so far (probably the same "made in mexico" transistor as KSE13009).
As you can see, only certain transistors work well with the new flybacks as most of them fry very quickly and cost you dollars :<>

DISCLAIMER
The author assumes no liability for any incidental, consequential or other liability from the use of this information. All risks and damages, incidental or otherwise arising from the use or misuse of the information contained herein are entirely the responsibility of the user, have a nice day!

12VDC Fluorescent Lamp Driver

A number of people have been unable to find the transformer needed for this project, so I looked around to see if I could find a fluorescent lamp driver that does not require any special components. Here it is. It uses a normal 120 to 6V stepdown transformer in reverse to step 12V to about 350V to drive a lamp without the need to warm the filaments.

If u have Any doubts mail me-----krishna.hacker@gmail.com

Parts
C1 --100uf 25V Electrolytic Capacitor
C2,C3 --0.01uf 25V Ceramic Disc Capacitor
C4 --0.01uf 1KV Ceramic Disc Capacitor
R1--1K 1/4W Resistor
R2--2.7K 1/4W Resistor
Q1--IRF510 MOSFET
U1--TLC555 Timer IC
T1--6V 300mA Transformer
LAMP--4W Fluorescent Lamp
MISC--Board, Wire, Heatsink For Q1
Notes
Q1 must be installed on a heat sink.
A 240V to 10V transformer will work better then the one in the parts list. The problem is that they are hard to find.
This circuit can give a nasty (but not too dangerous) shock. Be careful around the output leads