Amplifying Current in Monostable Circuit for Brighter LED Strip: A Solution

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Discussion Overview

The discussion revolves around designing a monostable circuit using a 555 timer to control a 12V LED strip, specifically addressing the issue of insufficient current output from the timer leading to dim lighting. Participants explore potential solutions for amplifying the current to achieve brighter illumination.

Discussion Character

  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant describes their circuit setup using a 1000µF capacitor and a TIP31C NPN transistor to amplify current, but reports that the LED strip does not light up.
  • Another participant questions the connection of the LED anode to the battery positive and suggests adding a resistor in series with the transistor's base to limit current.
  • A participant expresses confusion and frustration about the circuit's operation and mentions the presence of resistors on the LED strip.
  • One participant requests a circuit diagram to better understand the connections made in the setup.

Areas of Agreement / Disagreement

The discussion remains unresolved, with multiple competing views on the correct wiring and component usage. Participants have not reached a consensus on the solution to the problem.

Contextual Notes

There are limitations regarding the clarity of the circuit connections, and assumptions about component values and configurations are not fully detailed. The effectiveness of the proposed solutions has not been validated.

wavy
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Hi,

I am trying to make a Monostable circuit with my 12V LED strip. When I push the switch once, the LED strip will light up for 10 seconds and go off by itself. I have built the circuit using this schematic, the only difference is I am using a 1000uf capacitor.

309pzl2.jpg


Everything works, but the only problem I have is the 555 timer can only output 200mA, so the LED strip is very dim. I understand that I could use a TIP31C NPN transitor to amplify the current? What I did was wire the base to pin 3, the collector to the negative pin of my LED strip and the emitter to pin 1(ground). THe LED doesn't light up at all.

I am not really an expert in electronics, I hope someone can help me. Thank you.
 
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Do you have the LED anode connected to the battery positive?

Also, you should place a resistor in series with the base to limit the current. The transistor BE junction is approximately a short circuit on the 555 timer output.
 
Hi uart,

Thanks for your reply. The positive is connected to the 220 resistor and to pin3. I have attached a 3D view of the circuit. The LED strips appears to have resistors on them.I'm currently blurred trying to get this to work, I will have to look at the resistor part when I solve this. Been looking for a solution for days..
 
Last edited:
wavy said:
Hi uart,

Thanks for your reply. The positive is connected to the 220 resistor and to pin3. I have attached a 3D view of the circuit. The LED strips appears to have resistors on them.

I'm currently blurred trying to get this to work, I will have to look at the resistor part when I solve this. Been looking for a solution for days..

You need to post a circuit diagram of how you actually have it connected. Otherwise this is futile.
 
Issue solved.
 
Last edited:

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