The installation of an LED for the Projector Lamp is somewhat more difficult than the retrofit of a Halogen Lamp. But the effort is worth it! Now there are no more burned films.

The circuit diagram above shows a simple variant of the LED driver. The 4700μF capacitor is used to provide a current of 1A with acceptable ripple. The flickering is thus largely avoided. This approach is designed to help reproduce a movie.

The potentiometer could be omitted because the range between 700 mA and 1 A is the operating current at a luminous flux of 280 lm. The change of the color location has no influence on my application. Thus, the pulse width modulation is not necessary.

Cooling is necessary to avoid a high temperature of the projector LED. At high temperature diffusion of the dopants occurs and the intensity of the light, this means the luminous flux with lumen indication decreases. But with a fan there should be no difficulties, even with a 20 W LED the range of brightness to expand.

The holder consists of a piece of copper wire, diameter 4 mm and tinplate.

The fan also serves as a holder for the LED module, as the other pictures show. Place under the lamp cover is enough with a used 486 processor heat sink. The fan is new! Instead of the drive-in screws, I use machine screws with metric threads.

The LED module now sits instead of the mirror.

I use the Ostar 4-CHIP-LED (LEWE2B, OSRAM), Luminous Flux: 280 lm at 700 mA, Operating Voltage: 15,2 V, Dissipation: 10 W. There are already more efficient LEDs for a retrofit of a Movie Projector Lamp .

The operating voltage of 15.2 V I is usable, since the transformer supplies a voltage of approx. 19 V.

The OSTAR® Lighting description provides more information.