Model Trains are my hobby. I am 68 years old and retired. I am setting up a lighting system on my train layout. I want to use the LM317 to provide an adjustable brightness function for each building on the layout. I am a novice electronics person. I created the circuit shown in http://electronics-diy.com/1.5v--30v-1.5a-lm317-variable-power-supply.php. This circuit only allowed me to adjust the brightness of the one (1) White LED in the circuit. When I connected three (3) LEDs in series with 100 ohm resister the LEDs would not come on at any level of the potentiometer. What changes do I need to make to this circuit, so it will handle three LEDs. Also, how many LEDs can I expect to operate from one (1) of these circuits and how should the LEDs be arranged in the circuit, series, parallel or something else.
http://electronics-diy.com/1.5v--30v-1.5a-lm317-variable-power-supply.php
Thanks
Charles Malone
http://electronics-diy.com/1.5v--30v-1.5a-lm317-variable-power-supply.php
Thanks
Charles Malone