Understanding and Safely Using a 36-LED Circuit Board
Recently, I came across a 36-LED circuit board salvaged from an AC light. The LEDs are arranged in series, and upon testing with a 5V DC power supply, no flicker was observed. This raises the question: what DC voltage is needed to illuminate the LEDs safely and effectively?
The Hazards of High Voltages
Based on the description of the circuit board, it is advisable to handle this project with caution, especially given the high voltage involved. The circuit board operates with a potentially lethal voltage, typically over 50 volts. This voltage is beyond the recommended limit for experimenting safely without proper safety measures.
Reverse Engineering and Experimentation
Based on your query, it appears you have completed the complex task of reverse engineering the LED configuration. This is indeed a significant achievement. However, it's worth noting that obtaining insights from both sides of the board could have provided more context for specific design considerations and potential risks.
Safe Experimentation Techniques
One approach to safely experimenting with this circuit is to create multiple short chains of LEDs in series by desoldering every 8th LED. This method allows for a secure connection to solder wires, forming shorter strings. Adding a resistor to each short chain and using a suitable 50V supply can effectively illuminate these shorter strings of LEDs. While this method may not achieve the full brightness of the 36-LED chain, it significantly reduces the associated risks.
It is important to remember that a single failed LED in the 36-LED chain can cause the entire chain to fail. LEDs tend to fail in an open circuit, leading to an arcing effect inside the LED package, which can be a dangerous situation, especially with high voltage supplies. By dividing the LEDs into smaller, parallel chains, the risk of a catastrophic failure is mitigated.
Using LED Drivers for Safety and Efficiency
A safer and more efficient method to drive these LEDs is by using LED drivers. These devices are designed to provide a constant current supply, which is crucial for maintaining the longevity and optimal performance of LEDs. You can use a constant current supply of 300mA or 600mA with an open circuit voltage of 24V or 36V.
Parallel shorter strings of LEDs can be connected to these drivers, allowing for even illumination without the need for individual resistors. If the LEDs share the same heatsink, they will operate at similar temperatures, ensuring uniform performance. This approach not only reduces the risk of failure but also simplifies the circuit design.
While some may argue against this approach, it has proven effective in various applications. If you prefer to use a higher voltage, proceed with extreme caution and ensure all safety measures are in place.
Good luck with your project! Remember, safety always comes first. Enjoy your experiment!