led/maglite circuit

Hi everyone
this is my first post been reading eveything (only on page 34 so far ) ,but i built this circuit
**broken link removed** ,the dark activated one ,this is for an rc boat to help keep track of it at nite. i changed the circuit by not putting the relay in ,and instead added a 500 ohm resis. with 3 led's in series (jumped across the diode just like the relay) now im trying to add a " AAA" maglite light buld in series with it ,but its not working , i just jumped across one of the led's to see if it would work before unsoldering the circuit ,
not sure if its considered an incandesent light and thats why its not working or not ,
thought as long as power went through it ,it would light,well just tried it in series and the led's lite up but not the maglight,put multi tester on and its geting 6 volts..not sure any help and idea's would be appreciated ........... ,hope thats enough info as im not sure that its considered my circuit being i changed it some .. THANKS for any help !!

You can't replace an LED with a bulb!, a bulb takes vastly more current, feeding a maglight bulb through a 500 ohm resistor isn't going to produce any light at all. Assuming it's a 6 volt bulb you should connect it directly across the supply, you might need to uprate the transistor to handle the current (or use the original relay to switch the bulb) - and bear in mind the battery life will be EXTREMELY shortened.

Hi Rt,
I bet you're trying to use a Maglite bulb because your LEDs didn't light or were too dim. Red LEDs require about 2V each, plus some voltage for the current-limiting resistor. White LEDs need much more voltage.
Instead of using an incandescent bulb that eats batteries by producing 90 percent heat and only 10 percent light, try using a single ultra-bright white LED in series with a 100 ohm resistor. It will be very bright with your 6V supply.
Four alkaline AAA cells will power it for about 40 hours.
The LED shines in a narrow beam so will need a diffuser.

Hi Guy's
Thanks for the replies,
with all the info i belive i got what your all saying ,all use all led's, instead of the maglite,
the led's only need to run for about 20 minutes at a time,so im guessing that if i use 2 bright white leds and 2 green i should be pretty safe on that and a 100 ohm resis...
all set this up and see how it works.once again thanks for the help and info. 8)