DIY Car Boot Light Using 1W LED

[SPELLBOUND]

I have seen many cars that have boot light that glow all the time whenever we open the boot even there were enough day light and consumes battery power. This make me think to make a simple circuit that make the light glow only when at night so I goggled for the circuit and made one with is damn good the total cost of the circuit is only around 70
The circuit diagram














The sensor fixed on the tail gate

 

[Kichu]

Good job

What is that Black rectangular area below the LED.?

 

[SPELLBOUND]

Good job

What is that Black rectangular area below the LED.?

That's a plastic piece which i used to mount the led

 

[Varun560061]

Nice work ! Do you have any idea about cabin lamp dimmer as in other new cars. I was planning to get a circuit for the same.

Do post day time pic's showing where the led is mounted..

 

[SPELLBOUND]

Nice work ! Do you have any idea about cabin lamp dimmer as in other new cars. I was planning to get a circuit for the same.

Do post day time pic's showing where the led is mounted..

I already have that.

You can use a 3000uf capacitor parallel to the bulb (if you are using an led it will dim slower) You can increase the discharge timing buy using higher capacity capacitor the capacitor must be greater than 12V

 

[Kichu]

That's a plastic piece which i used to mount the led

Plastic base is not a good practice. Be sure not to use it for more duration. (ya its common sense, this led wont be used for long time since it is for the made of the boot usage but still saying.)

What's the forward voltage?(Even though you have given a detailed circuit its not handy for me to calculate the output voltage from it) Have you checked using a multimeter? If it is lower than what recommended then there wont be much issue.



Usually 1watts led need to be mounted on a heat sink for the LED heat dissipation.

Attaching the pic of my three 1 watts led DIY

 

[SPELLBOUND]

I already have that.

You can use a 3000uf capacitor parallel to the bulb (if you are using an led it will dim slower) You can increase the discharge timing buy using higher capacity capacitor the capacitor must be greater than 12V

View attachment 127998

View attachment 127999

Have look to the circuit that i connected across the diode. The diode is used for converting the out put 12v to 3.3v which is enough to glow the 1w led and the forward voltage of 1w led is rated at 3.0V to 3.4V. I don't have any issue so far using plastic for the base and also the led have a petal shape heat sink which is enough for a 1w led.

For checking i had opened the tail gate continuously for about 4hours and don't have any problem and i had done this one year before.

 

[SPELLBOUND]

Plastic base is not a good practice. Be sure not to use it for more duration. (ya its common sense, this led wont be used for long time since it is for the made of the boot usage but still saying.)

What's the forward voltage?(Even though you have given a detailed circuit its not handy for me to calculate the output voltage from it) Have you checked using a multimeter? If it is lower than what recommended then there wont be much issue.



Usually 1watts led need to be mounted on a heat sink for the LED heat dissipation.

Attaching the pic of my three 1 watts led DIY

Have look to the circuit that i connected across the diode. The diode is used for converting the out put 12v to 3.3v which is enough to glow the 1w led and the forward voltage of 1w led is rated at 3.0V to 3.4V. I don't have any issue so far using plastic for the base and also the led have a petal shape heat sink which is enough for a 1w led.

For checking i had opened the tail gate continuously for about 4hours and don't have any problem and i had done this one year before.

 

[SPELLBOUND]

Nice work ! Do you have any idea about cabin lamp dimmer as in other new cars. I was planning to get a circuit for the same.

Do post day time pic's showing where the led is mounted..

This is What i had done in my car to dim the cab light

 

[Kichu]

Have look to the circuit that i connected across the diode. The diode is used for converting the out put 12v to 3.3v which is enough to glow the 1w led and the forward voltage of 1w led is rated at 3.0V to 3.4V. I don't have any issue so far using plastic for the base and also the led have a petal shape heat sink which is enough for a 1w led.

For checking i had opened the tail gate continuously for about 4hours and don't have any problem and i had done this one year before.

Actually its not the diode, its the LD33v Voltage Regulator step-downs the voltage from 12v to 3.3v.

Good to hear that, In my case two of my LEDs blown because of the poor heat dissipation. and later I brought heat sink paste to get a better contact between them. I use them 6 hours daily.

I think your LED may not be operating at its highest possible current.
My 1watts led gets lot of heat.

 

[SPELLBOUND]

Actually its not the diode, its the LD33v Voltage Regulator step-downs the voltage from 12v to 3.3v.

Good to hear that, In my case two of my LEDs blown because of the poor heat dissipation. and later I brought heat sink paste to get a better contact between them. I use them 6 hours daily.

I think your LED may not be operating at its highest possible current.
My 1watts led gets lot of heat.

That i knew that it is not a diode. What i mean was that i connected the voltage regulator across the diode.

You are right that the led is not working at its maximum even though it have enough brightness to cover the entire boot area.

 

[Kichu]

That i knew that it is not a diode. What i mean was that i connected the voltage regulator across the diode.

You are right that the led is not working at its maximum even though it have enough brightness to cover the entire boot area.

Okay, then its fine.

Actually whats the purpose of this IN4001 Diode, really I can't get it May be my ignorance, I feel this circuit works even if that diode is not connected across the LED.
Have you got the explanations of this circuit from this circuit designer?

If it is illuminating well then what to worry isn't it. Anyways operating with a bit lower current than recommended will helps in lasting longer.

 

[SPELLBOUND]

Okay, then its fine.

Actually whats the purpose of this IN4001 Diode, really I can't get it May be my ignorance, I feel this circuit works even if that diode is not connected across the LED.
Have you got the explanations of this circuit from this circuit designer?

If it is illuminating well then what to worry isn't it. Anyways operating with a bit lower current than recommended will helps in lasting longer.

oh sorry as you said the circuit will work without the diode actually a relay is connected across the diode for powering high power light. relay produce reverse voltage ie generate by the collapse of the magnetic field when the voltage is removed form relay which may damage the IC so in order to avoid that a diode is used in this case a diode is not necessary u can neglect it.

 

[Kichu]

oh sorry as you said the circuit will work without the diode actually a relay is connected across the diode for powering high power light. relay produce reverse voltage ie generate by the collapse of the magnetic field when the voltage is removed form relay which may damage the IC so in order to avoid that a diode is used in this case a diode is not necessary u can neglect it.

Ok! Really thanks for the detailed explanations

 

[SPELLBOUND]

Ok! Really thanks for the detailed explanations

You can use this circuit for automatic headlamp, foglamp (when your vehicle suddenly enters into a darker area or a tunnel) or even as headlamp dimmer.