DIY IR Remote-Controlled Bulb — BC547 + IR receiver for simple remote switching

DIY IR Remote-Controlled Bulb Circuit — Control Lights with a Remote

Posted by GSM4Files · Quick build · No microcontroller required

Turn a 220V lamp ON/OFF with any TV remote — no coding, no MCU. This compact IR remote-controlled bulb circuit uses a cheap IR receiver and a BC547 transistor to toggle household lights. Perfect for a weekend DIY, classroom demo, or quick home automation hack.

Parts & Tools

  • 1 × BC547 (NPN transistor)
  • 1 × IR receiver module (e.g., TSOP1738 or similar)
  • 1 × 220 Ω resistor (for sensor protection)
  • 1 × AC bulb rated for 220V
  • AC mains supply (220V) — exercise extreme caution
  • Insulated wires, connector block, isolation box, screwdriver

How It Works (simple)

The IR receiver listens for remote pulses (38kHz). When a button is pressed it outputs a signal that drives the BC547 base (through the resistor). The transistor switches current so the bulb can light. Press again (or another remote code) and the output changes — toggling the lamp. This circuit is low-cost and easy to solder into a small plastic enclosure.

Step-by-step Build

  1. Mount the IR receiver on the enclosure where it sees the remote.
  2. Connect the receiver output to the BC547 base via the 220Ω resistor.
  3. Wire the BC547 collector in series with the AC bulb (using proper safety/isolation). The emitter goes to neutral/return as per your wiring plan.
  4. Double-check insulation and secure all mains connections in a terminal block or enclosure.
  5. Test with a low-wattage bulb first. Use the remote to toggle the lamp.

Safety Notes (must read)

  • ⚠️ This project involves 220V AC mains — dangerous and potentially lethal. If you are not experienced with mains wiring, do not attempt — use a relay module or seek electrician help.
  • Use proper insulating enclosures, strain relief, and fuse protection.
  • Consider using an optocoupler or mains-rated relay for safe isolation when driving higher loads.

Troubleshooting

  • If the bulb doesn’t turn on, check the IR sensor orientation and test the BC547 with a multimeter.
  • If the IR receiver is noisy, try adding a small capacitor (100nF) across its Vcc/GND pins.
  • Replace the BC547 with a higher-power transistor or use a mains-rated relay if the bulb draws high current.

Applications & Next Steps

Use this as a learning step to upgrade into a safer design: add a mains relay controlled by the transistor, or use a triac-based circuit with proper snubber for AC switching. Great starter project for home automation experiments.

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Posted by GSM4Files · Learn, build & repair smarter.