With the circuit shown here you can create high frequency electromagnetic waves with very high output power.
Possible applications are experiments with wireless power transmission, RFID Transponder, tesla coils and the like.
Dependent on the coil, capacitor and cooling of the transistors output power in the range of 20W and more can be obtained.
At short distances, other electronic circuits may be disturbed or even destroyed. Broadcasting, RFID, AntiTheft, Wlan, medical appliances (pacemakers!) can be disturbed in a large area!
Never operate this circuit without taking precautions !
It may be illegal to operate in your Country!
The Circuit:
It is a standard Push Pull Oscillator, based on Power Mosfet Transistors.
The PCB provides mounting space for two SK104 heatsinks, this allows for remarkable output power for such a small device.
For a high resolution layout, click on the Image!
Component Values:
Operation Voltage is about 15V DC
If you wish to use smaller operating voltages, you must increase R2 and R3. Oscillation starts when the voltage drop across R2 resp. R3 reaches the MOSFET’s thresold Voltage, approx. 4..6V
Mosfet: IRF510
R1, R4 100k
R2, R3 27K
C4, C5 100u
C1 choose for your desired frequency
C2,C3 ca 10% of C1
D1,D2 15V Z-Diodes
A PushPull Oscillator requires a coil with a Center Tap. For my tests i used 12 Turn 1mm insulated Copper Wire, ca 40mm Diameter.
The Center Tap is connected to PAD1
A Frequency Range from 200kHz to 10MHz was generated using this coil.
The Resonance Frequency of the is calculated by (approx)
Important!
The Capacitors, especially C1 should be low ESR, otherwise they will heat up and be destroyed!
A LED connected to a small receiver coil lit up at about 20cm distance. At 10 cm, it became hot and was destroyed eventually!
Source:skemarangkaian.com