Bright light from white light connected 240ac through 1k

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Discussion Overview

The discussion revolves around the issue of insufficient brightness from a circuit involving four white LEDs connected to a 240VAC source through a 1K resistor. Participants explore potential solutions and safety concerns related to the setup.

Discussion Character

  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the nature of the "unsatisfactory" brightness and asks for specific brightness requirements.
  • Another suggests using more LEDs or wiring them in parallel as possible solutions.
  • A different participant proposes lowering the resistance and mentions that diodes are typically rated for DC current, suggesting pulsing the LEDs might allow for higher current without overheating.
  • Concerns are raised about the setup, with one participant noting that a 1K resistor in series with 240VAC could lead to excessive current and potential damage to the LEDs.
  • Safety concerns are emphasized, with participants warning about the dangers of working with 240V and the importance of using appropriate components.
  • One participant expresses skepticism about the viability of the described circuit, suggesting it should have failed catastrophically if constructed as stated.

Areas of Agreement / Disagreement

Participants express significant concern regarding the safety and correctness of the circuit setup, indicating a lack of consensus on whether the described configuration is safe or effective. Multiple competing views on how to address the brightness issue and safety concerns remain unresolved.

Contextual Notes

There are unresolved assumptions regarding the specifications of the LEDs used, the rating of the resistor, and the overall safety of the circuit. The discussion highlights the need for clarity on these points.

Who May Find This Useful

Individuals interested in electronics, particularly those working with LED circuits and high-voltage applications, may find this discussion relevant.

pmostafa
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I have connected 4 White LEDs with 240ac main through 1K resistor in series. The brightness of the output is not satisfactory. What can i resolve this issue?

Thanks
 
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In what way is the brightness "unsatisfactory"?
How bright do you need?

Have you tried using more LEDs?
Have you tried wiring them in parallel?
 
Or lowering the resistance?

Diodes are often rated for their DC current. Often this is because the junction overheats if over driven. So if the LEDs are pulsed you might be able to go a little over their DC rating since temperatures are based on continuous current draw.

If that's not enough, use a diode rectifier and a capacitor to make your current DC. I doubt the power needs to be too clean, so nothing fancy.
 
pmostafa said:
I have connected 4 White LEDs with 240ac main through 1K resistor in series.
What is the white LED you are using?
240VAC with 1k in series will give a forward current of 240mA, then the reverse voltage will destroy the diodes.
The 1k resistor will need to be rated at 60 watt.
 
Baluncore picked up on the fact something seem very wrong in your description.

What you describe should have already gone up in smoke.

Can you assure us somehow that you experiment is not about to hurt you or some tiny fingers in your household ?
 
Since he got some light out of the diodes, I assumed he used appropriate parts.

Working with 240V is dangerous. Don't do it unless you are a licensed professional.

If the parts were chosen properly, the circuit should work. If they weren't, out comes the magic smoke. (At 240V this could be dangerous in so many ways.)
 
jim hardy said:
Can you assure us somehow that you experiment is not about to hurt you or some tiny fingers in your household ?

Agreed. Pmostafa, I'm locking this thread for the time being. If you wish, please send me a message and we can discuss reopening it.
 
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