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Hahaha, try asking GPT-3 about electronic engineering. --- Transcript of IRC channel #electronics: Mordae: Hi. So I was designing a transformerless LED bulb
by mordae 4y ago
Hahaha, try asking GPT-3 about electronic engineering.
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Transcript of IRC channel #electronics:
Mordae: Hi. So I was designing a transformerless LED bulb and I was wondering about the filter capacitor. What happens when the load (one of the LEDs) fail?
Rampant: Hi Mordae. It really depends on the design, but the general idea is that the filter capacitor will help prevent spikes and other issues caused by the failing LED. It can also help with voltage regulation.
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Actual answer: Light bulb needs a bulky electrolytic cap. Those are usually not 400V tolerant. You are looking at 60V at best at the required sizes. Losing the load will swiftly charge up the capacitor to 325V. But well before that happens, there are going to be fireworks: https://www.youtube.com/watch?v=6WUxgmMDts4 https://www.youtube.com/watch?v=6WUxgmMDts4
I believe that there are eventually going to be useful mentors for bunch of fields, but right now it's crazy dangerous to blindly follow its recommendations.
- whartung 4y agoI'm sorry, is there enough context in the original question as presented to come up with your "actual answer"? I mean, I don't know, I'm not an EE, lucky I can make a light switch work. But given the dearth of details in the query, is that AI answer grotesquely wrong? Just seems like generic advice.
- Dylan16807 4y ago> I'm sorry, is there enough context in the original question as presented to come up with your "actual answer"? I'd say there is. "Transformerless" implies a specific design, especially when you mention there's a filter capacitor. > is that AI answer grotesquely wrong? Yes. It's fine to say the filter cap helps with "spikes and other issues", but not ones caused by a failing LED. It took half a true sentence and made it into a false sentence. In this design the filter cap is something you give protection to much more than something that provides protection.
- deleted 4y ago[deleted]
- Bjartr 4y agoChatGPT does a much better job. Not perfect, but at least identifies overcharging the capacitor as a danger (though not fireworks) and provides some possible mitigations to look into (NOT take at face value as definitely correct though, to be sure) --------------------- I'm designing a transformerless LED bulb and I was wondering about the filter capacitor. What happens when the load (one of the LEDs) fail? --------------------- When a load (such as one of the LEDs in your transformerless LED bulb) fails or becomes open-circuited, the current through the filter capacitor will drop to zero, and the capacitor will start to charge up to the peak value of the AC voltage from the mains supply. This can be dangerous because the voltage across the capacitor can quickly rise to a high level, depending on the capacitance value and the AC voltage level. If a person were to touch the exposed conductors of the failed LED bulb, they could receive a potentially lethal electric shock from the charged capacitor. To mitigate this risk, it's important to include some form of overvoltage protection in your design, such as a discharge resistor or a metal oxide varistor (MOV). The discharge resistor will discharge the capacitor when the load is disconnected, while the MOV will clamp the voltage across the capacitor to a safe level by diverting the excess energy to ground. It's also important to provide adequate insulation between the live components and any exposed conductors or casings to prevent accidental contact with live parts. Additionally, it's recommended to follow established safety standards and guidelines when designing any electrical product to ensure its safety for users
- Tade0 4y agoOut of curiosity I looked up the circuit for that. Designing a LED power supply as anything else than a current source is asking for trouble.