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» »Stabilizer for LEDs and DRL
Almost all motorists are familiar with such a problem as the quick failure of LED lamps. Which are often put in the side lights, daytime running lights (DRL) or in other lights.
Typically, these LED lamps have low power and current consumption. Than actually speaking and their choice is caused.
By itself, the LED easily serves in optimal conditions for more than 50,000 hours, but in the car, especially in the domestic one, it is sometimes not enough for a month. First, the LED starts to flicker, and then it burns out altogether.
Stabilizer for LEDs and DRL

What is the reason for this?


The lamp manufacturer writes the “12V” marking. This is the optimal voltage at which the LEDs in the lamp operate at almost maximum. And if you apply 12 V to this lamp, then it will serve at maximum brightness for a very long time.
So why does it burn out in a car? Initially, the voltage of the vehicle’s on-board network is 12.6 V. An overstatement of 12 is already visible. And the voltage of the wound-up vehicle network can reach up to 14.5 V. We add to all this various surges from switching high-power high or low beam lamps, powerful voltage pulses and magnetic interference when starting the engine from the starter. And we will not get the best network for powering LEDs, which, unlike incandescent lamps, are very sensitive to all changes.
Since often in simple Chinese lamps there are no limiting elements other than a resistor, the lamp fails from overvoltage.
During my practice, I changed dozens of such lamps. Most of them did not serve even a year. In the end, I got tired and decided to look for a simpler way out.

Simple voltage regulator for LEDs


To ensure comfortable operation for LEDs, I decided to make a simple stabilizer. Absolutely not complicated, any motorist can repeat it.
All we need:
  • - ,
  • - ,
  • - .
  • - a piece of PCB for the board,
  • - .

Look like that's it. All equipment costs a penny on Ali express links in the list.

Stabilizer circuit


Stabilizer for LEDs and DRL

The scheme is taken from the datasheet on the L7805 chip.
Stabilizer for LEDs and DRL

Everything is simple - the entrance is on the left, the exit is on the right. Such a stabilizer can withstand up to 1.5 A load, provided that it is installed on the radiator. Naturally for small bulbs no radiator is needed.

LED Stabilizer Assembly


All you need is to cut out the desired piece from the PCB. You do not need to poison the tracks - I cut out simple lines with an ordinary screwdriver.
Solder all the elements and you're done. Does not need to be configured.
Stabilizer for LEDs and DRL

Stabilizer for LEDs and DRL

In the role of the body serves as a blower.
The plus of the circuit is that it is fashionable to use a car body as a radiator, since the central output of the microcircuit housing is connected to the minus.
Stabilizer for LEDs and DRL

That's all, LEDs no longer fade. I’ve been traveling for more than a year and forgot about this problem, which I advise you.

Watch assembly video


come back
Comments (8)
  1. Victor
    #1 Victor Guests January 19, 2018 10:18
    0
    Everything is fine, but.
    And the flange of the microcircuit does not short-circuit the plus and minus for an hour, insulation is not visible. When the lamp is in good power, good power will be allocated on the LM-ke and the insulation needed is not melting.
  2. Vladimir
    #2 Vladimir Guests January 20, 2018 06:29
    4
    It is more correct to stabilize not the voltage on the LEDs, but the current through them. The easiest option is LM317. Set the current value to 90% of the maximum value for this diode.
    1. Dimka
      #3 Dimka Guests January 20, 2018 11:16
      2
      You are not quite right! For LEDs, yes - it is better to stabilize the current. But for finished lamps with resistors inside, you just need to stabilize the voltage! Because the current for them to stabilize does not work.
  3. Alexpanych
    #4 Alexpanych Guests January 22, 2018 12:50
    1
    In fact, a small increase in the supply voltage is not scary for LEDs with resistors.
    The problem is that in a car in the on-board network there are significantly larger power surges, just look at the standard for testing devices for the on-board network:
    Surge + -100V can be normal. Yes, it is from -100 to +100 volts.
    Thus, in order to protect oneself as an adult, the first should be a diode with a permissible reverse voltage of at least 100V, fine if it is up to 1000V.
    But then you need a stabilizer. And since we already have a resistor, it should only “eat” throws so as not to heat up. Therefore, I would advise you to take not 7812 (stabilization voltage from +11.5 to +12.5), but 7815 (from +14.4 to +15.6). I think this is quite enough. And it will not warm up.
    But the author is right - the less current through the LEDs, the longer they will last. And if the manufacturer underestimated the resistance of the limiting resistor in order to get brighter light from cheap LEDs, then it is logical to choose 7812 with a lower output voltage.
  4. Dmitry
    #5 Dmitry Guests 23 january 2018 11:22
    1
    And all would be fine, but, according to the description of the microcircuit, capacitors should be at least 2.2 microns in capacity for tantalum or ceramic, and at least 10 microns for electrolytes. The dissipation power is 8 W, so when using high-power LEDs, a heat sink is needed. Note also that the minimum input-output voltage difference must be at least 2.5 volts (12 + 2.5 = 14.5), so if the battery is not very good and the light, music and stove are turned on, there will be no sense from the circuit from the word "completely" ...
  5. Vladimir
    #6 Vladimir Guests February 3, 2018 7:05 p.m.
    1
    The reference probably needs to be corrected; the chip 7805 is indicated for 5V, but it is still necessary for 7812 for 12V
  6. Guest Vladimir
    #7 Guest Vladimir Guests March 17, 2018 08:01
    0
    This is our way, just try ...
  7. Ha
    #8 Ha Guests September 13, 2018 08:23
    1
    It is necessary to stabilize the CURRENT, not the voltage.

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