Flyback Transformer (25kV AC)

Elevate your high-voltage and high-frequency experiments with our next-generation flyback transformer, now shipped with a pre-installed polyimide ferrite sleeve as standard. Engineered to manage substantial power demands and effortlessly initiate plasma under even the most challenging conditions, this transformer is ideal for plasma physics, spark-gap experiments, and resonant circuits—making it a must-have for serious hobbyists and professionals alike.

The transformer is available with two secondary winding options, allowing you to choose the configuration that best suits your frequency range and experimental goals. Select the 2400-turn secondary for lower-frequency, high-voltage resonance applications, or the 1000-turn secondary for extended high-frequency operation up to 100 kHz.

Key Features:

• No Built-In Diode: Designed without an internal diode, this transformer supports versatile AC-circuit applications. By omitting the diode, the transformer manages alternating current effectively, allowing for pure AC output—perfect for high-voltage and high-power experiments.
   
• Adjustable Core: The detachable core lets you modify the gap on both primary and secondary sides, enabling precise resonance tuning and current limitation during short circuits.
   
• Customizable Secondary Options: Choose between a 2400-turn secondary optimized for lower-frequency resonance (0–50 kHz), or a 1000-turn secondary designed for higher-frequency operation with an unloaded resonant frequency around 100 kHz and a usable range of 0–100 kHz. Both versions are fully encapsulated in epoxy for long-term durability and high-voltage reliability.
   
• Configurable Primary Winding: The primary is delivered unwound, giving you full freedom to tailor it to your application. For convenience, you may select our pre-wound primary option (40 turns for power delivery plus 4 turns for feedback), designed for seamless compatibility with our Half-Bridge Amplifiers.
   
• Extended Frequency Range: Depending on the selected secondary winding and core gap adjustment, resonance can be achieved from near DC up to either 50 kHz (2400 turns) or 100 kHz (1000 turns). Both configurations are capable of reaching output voltages up to 25 kV AC (50 kV pk-pk).
   
• High Power and Voltage Capability: When paired with our Half-Bridge Amplifier, the transformer delivers near-perfect sine-wave output and supports power levels up to 300 W. The design enables reliable plasma ignition in standard atmospheric conditions and can strike arcs across spark gaps up to 60 mm.
   
• Polyimide Ferrite Sleeve Included: The sleeve forms a robust barrier between the ferrite core and the secondary winding, where breakdown is most likely to occur at extreme voltages. Its polyimide construction offers excellent electrical insulation, slides easily onto the core for straightforward assembly or disassembly, and significantly reduces corona, ozone generation, and localized heating.
   
• Convenient Mounting Option: Includes a sturdy bracket for easy chassis mounting, making integration into larger projects seamless.

Rated for 300 W, it’s essential to monitor temperature during extended operation to prevent overheating. When operating near the transformer’s upper-voltage rating, the included sleeve helps minimize corona discharge and ozone generation; nevertheless, ensure good ventilation and maintain a safe distance between electrodes to protect the core during high-voltage experimentation. For continuous operation at the highest voltage levels, submerging the transformer in transformer oil is highly recommended—it greatly improves cooling and virtually eliminates corona and ozone production.

Installation Tip: Be sure to orient the coil so that the high-voltage output lead is positioned as far away from the ferrite core as possible. This is where breakdown and internal arcing typically occur under high-voltage stress.

This transformer has demonstrated the ability to exceed 25 kV output; however, we do not currently have measuring probes to confirm this precisely. One practical verification method is observing plasma initiation over a 6 cm spark gap, achieved when the transformer is tuned close to its resonance frequency (approximately 46 kHz for the 2400-turn secondary with only a spark gap connected).

Technical Specification: