I am new to the forum so I hope this is not a redundant thread. I'm trying to find an economical way to provide power to 1.5v 15ma and 40ma lamps (light bulbs). Using a power adapter is easy enough but with only 3 amps I can only power only a few lamps. Any ideas on a more powerful power source? I have plans for lighting several structures and some, such as a roundhouse and passenger station, have more lamps than a 3 amp power supply can handle.
Thanks!
A 3 amp power supply will power a LOT of 15 and 40 ma bulbs. If the output voltage is correct ie 1.5 volts you can power apprx 200 15 ma bulbs or 75 40 ma bulbs. Remember 3 AMPS is 3000 MILLIAMPS. You would of course have to wire all the bulbs in parallel. If the supply voltage is higher you would have to wire in some sort of parallel/series circuit, on 12 volts you would need something like 8 or 10 bulbs in series, (depending on desired brightness) which would use 12volts at 15 ma or 40 ma depending on the bulb. Total current in a series circuit would be the supply voltage divided by the "total" resistance of the circuit, (Ohms Law).
renegade99, thanks for the info. I checked the numbers on my power adapter and it is 300ma so I did the math wrong when I said it was 3 amp. My understanding is that I should add up the total amps of the light bulbs in the circuit so if I'm figuring this correctly 40ma goes into 300ma 7.5 times which means I can only power 7 bulbs.
And, you will need to add resisitors to the bulbs or LEDs to avoid instant burn out when power is applied from a higher voltage source.
Rich
Alton Junction