Can a 1n4009 protect a LED from reverse breakdown voltage when powered by mains?

In summary, the individual is seeking advice on powering a LED off mains and has shared their proposed circuit. They have also expressed confidence in their ability to work with mains voltage but are open to suggestions for improvement. The other person in the conversation expresses hesitation in giving advice for mains powered projects and suggests a different circuit with skilled supervision. The individual further clarifies their circuit and asks for input on their approach.
  • #1
thankz
265
40
I want to power a led off mains, here's my thinking on it:

resistor-->led-->1n4009 to protect against reverse breakdown voltage, is there anything I'm missing and will it be reliable?
 
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  • #2
Im a bit unsure if I should be giving you circuit advice for mains powered projects
as I don't really know if you have the experience dealing with potentially lethal voltages

The way you described above isn't correct
You also haven't stated what mains voltage you have at your location or what type of LEDs you want to use

This gives me even less confidence in your knowledge level

The circuit I will give and strongly advise you follow and with skilled supervision is this one ...

220V-leds.jpg
Dave
 
  • #3
it's just 120 v ac, I don't see why I need a bridge rectifier and cap when all I want to is current and voltage limit a 1.2v led and use a 1n4009 to protect the led against reverse piv? maybe I'm not using the right terminology but I'm comfortable working around mains, I'm pretty sure I won't die. would you have questioned me if I had used a neon bulb and a resistor? basicly it's a half wave rectifier and I'm just adding a voltage drop and current limiting. if I used a varic and fast blo fuse, high wattage resistor I would test this out myself before asking, just wondering.
 
Last edited:

1. What is reverse breakdown voltage?

Reverse breakdown voltage is the voltage at which a diode or other semiconductor device begins to conduct electricity in the reverse direction, typically at a high current level. It is an important characteristic of these devices and is often included in their specifications.

2. How is reverse breakdown voltage measured?

Reverse breakdown voltage can be measured using a voltage-current curve, also known as an IV curve. This involves gradually increasing the voltage in the reverse direction while measuring the resulting current. The point at which the current suddenly increases is the reverse breakdown voltage.

3. Why is reverse breakdown voltage important?

Reverse breakdown voltage is important because it indicates the maximum voltage that a diode or other semiconductor device can withstand in the reverse direction before it begins to conduct. This is crucial for ensuring the proper functioning and reliability of electronic circuits.

4. How does reverse breakdown voltage affect electronic circuits?

If the reverse breakdown voltage of a diode or other semiconductor device is exceeded, it can lead to a breakdown in the circuit and cause damage or malfunction. Therefore, it is important to choose components with appropriate reverse breakdown voltage ratings for the specific circuit requirements.

5. Can the reverse breakdown voltage of a diode be changed?

The reverse breakdown voltage of a diode is a characteristic of its design and cannot be changed. However, it can be affected by external factors such as temperature, so it is important to consider the operating conditions when selecting a diode with a specific reverse breakdown voltage rating.

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