Since my soldering iron got damaged I could not de-solder components from the Compact Fluorescent Lamp (CFL) bulb circuit board today. I have to buy a new one, but until then I learned more about the CLF bulb circuit components. As part of learning how to build power supply, I have already talked and wrote about inrush current limiting resistor, PC817C optocoupler and, S8050 Transistor found in mobile phone adapters and CFL circuits. My interest began noticing the transformer used.in CFLbulbs and I know that transformer are used in AM and FM radio circuits. So I asked myself, whether a transformer of CLF bulbs or mobile adapter circuit are usable for building AM radio circuit or FM radio circuit? And here is the answer.
Yes, parts from a CFL bulb or a mobile charger (adapter) — especially the transformers — can sometimes be reused in making AM or FM radio circuits.
But there are important limitations you need to know.
⚡ Let's break it down:
| Source | Transformer Type | Can it help? | Notes |
|---|---|---|---|
| CFL Bulb Transformer | High-frequency ferrite transformer | ⚠️ Maybe | Designed for tens to hundreds of kHz, useful in AM but not directly tuned for audio. |
| Mobile Charger Transformer | High-frequency ferrite transformer (switch-mode) | ⚠️ Maybe | Operates at tens or hundreds of kHz, very tiny windings, not tuned for radio. |
In more detail:
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CFL transformers are high-frequency — they work at frequencies like 20kHz to 80kHz typically.
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Mobile charger transformers (in switching power supplies) also work around 50kHz to 100kHz (not 50/60Hz like old iron transformers).
🛠️ How they could be reused in radio:
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Oscillators:
You could use the ferrite transformer core or winding to build a local oscillator circuit, especially for AM transmitter or AM radio receiver projects. -
RF Amplifier Coupling:
You could use them to couple stages of a radio frequency (RF) amplifier (like transformer-coupled amplifiers). -
FM circuits:
Not ideal because FM (88–108 MHz) is very high frequency compared to what these transformers are made for — but you could still experiment with lower-frequency FM circuits or superregenerative receivers using parts. -
Audio output transformers:
If rewound properly, you could even use the cores for audio frequency amplification.
🚫 Limitations:
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They are NOT resonant coils ready for AM or FM detection — you’d usually need a proper air-core coil or a ferrite rod coil tuned for the target frequency.
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Their windings are optimized for power, not sharp tuning needed for a good radio.
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For FM, you need very small inductances and very fast circuits — most CFL or charger transformers are too bulky unless modified.
| Usage | CFL Transformer | Mobile Adapter Transformer |
|---|---|---|
| AM Oscillator | ✅ Yes, possible with mods | ✅ Possible |
| AM Detector/Receiver | ⚠️ Needs extra tuning | ⚠️ Needs extra tuning |
| FM Oscillator | ❌ Not ideal | ❌ Very hard without serious modification |
| FM Receiver | ❌ Not good | ❌ Not good |
🎁 Pro Tip:
Much easier:
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Use a small air-core coil or salvage old AM radio coils.
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Ferrite rods from old radios are perfect for AM.
Would you like me to show you a simple AM radio transmitter or super-simple AM receiver circuit you can build with CFL or mobile adapter parts? 🚀🎙️ (We could even modify a CFL transformer into a basic oscillator!)
