Hey folks i am just new into Arduino,
i have here 4 led christmas light chains which all have there own battery power source.
Now i want to let them blink to music, already got the sound modul set up and tested it with one single led,
which worked perfekt.
But how would i now connect the 4 led light chains to my Arduino Uno board, what would be the best way considering they gonna turn on and of within seconds Relays.. ?
Would be very happy about your ideas and tips.
Greetings Daniel
The "Christmas tree light" threads are arriving early this year.... it's only September!
Hi Daniel.
You can probably use ordinary transistors like bc337. But first you need to make some measurements to be sure. You will need a multimeter for this.
Describe each light chain. What kind of batteries does each chain take and how many? Do you want to run all chains from the same power source in the future, a larger battery or a mains adaptor, or keep the separate battery packs?
You need to use your multimeter to measure the current that flows through the leds in each chain. For this you will need to cut the wire somwhere between the last led and the negative side of the battery. Then you can strip off a few mm of insulator off and connect your multimeter. Put the multimeter on the highest current range to start. Don't start on the most sentitive range because you may damage the multimeter or blow its internal fuse.
I expect the current will be no more than a few hundred mA, in which case the bc337 would be fine. You will need a resistor connected between the transistor's base and the Arduino output. The choice of resistor will depend on the led current. the transistor's emitter goes to the negative battery wire and its collector to the leds. It is very important that the negative battery wire for the leds is connected to the 0V on the Arduino. This provides a "common ground" between the Arduino and the led chains.
Paul