The proposed "halogen" LED lamp replacement module image can be seen below:
Conventional filament type halogen lamp is shown below:
The image at the top shows an example LED lamp replacement for a standard halogen bulb fitting shown below it.
With
the easy and extensive availability of LEds, today it's quite possible
to make any desired LED lamp module at home for replacing other forms of
less efficient lamp options.
So here we'll discuss how to make the proposed halogen LED lamp replacement circuit. Let's learn the procedures:
Referring
to the above image, we can see the LEDs are wired over 7 separate PCBs
and then wired together to form one single module.
Each board can be seen with 3 LEDs each, constituting a total of 21 LEDs.
3nos
LEDs are selected because the supply 12V available from the vehicle
allows only 3nos to be connected in series, and series connection
facilitates sharing the same current across the three LEDs.
Now
since more than 3nos. of LEds cannot be accommodated in series, 7 such
strings are connected in parallel with each other for achieving the
desired 21 watts.
The above assembly must be done over a well designed heatsink cored glass epoxy PCB.
The above assembly must be done over a well designed heatsink cored glass epoxy PCB.
The
entire configuration may be tightly fixed over an thick hexagonal
aluminum cylindrical former or base to form the proposed halogen LED module unit. The aluminum will hep to sink the generated heat from the LEDs.
The above unit will strictly require a current controlled driver circuit which can be understood with the following points:
We once again take the help of the versatile LM338 IC for the required current control function.
Referring to the circuit diagram we ca see it in it's simplest current limiting mode. The LEDs consume around 2.5 amps together which is never allowed to exceed by the IC keeping the unit safe from the issue.
The above unit will strictly require a current controlled driver circuit which can be understood with the following points:
We once again take the help of the versatile LM338 IC for the required current control function.
Referring to the circuit diagram we ca see it in it's simplest current limiting mode. The LEDs consume around 2.5 amps together which is never allowed to exceed by the IC keeping the unit safe from the issue.
Comparison Between Conventional Halogen lamp and LED Halogen lamp Output
Output Conventional Incandescent LED Halogen Lamp
Specs Halogen
Nominal wattage 55 watts 21 watts
Nominal voltage 12V 12V
Test voltage 13.2V 13.2V
Color temperature 3200K 6000K
Luminous flux 1500lm 2500lm