TIP120 on breadboard - too much wattage?

Projects General Guidance
1

I'm following this example to have my Arduino Mega vary the voltage to my dragon ears. Each ear has a 12V strand of red LEDs. At full intensity, the total wattage for both ears will be (12V x 3A) X 2 ears = 72 Watts.

My concern is that the jumper wires I have for connecting breadboard/TIP120 to negative on ARD seem very thin. Can they handle 72 watts and, if not, what do you recommend?

TIP120.png

2

Larry_Tremaine:
Each ear has a 12V strand of red LEDs. At full intensity, the total wattage for both ears will be (12V x 3A) X 2 ears = 72 Watts.

My concern is that the jumper wires I have for connecting breadboard/TIP120 to negative on ARD seem very thin. Can they handle 72 watts and, if not, what do you recommend?

It's not the power (W), it's the current.
Describe the "strand" - What's the "3A" based upon?

3

I wouldn't use thin jumper wires for that, nor would I trust a breadboard to handle 6A.

I suspect if you run it like that, you'll find that the lights just aren't as bright as you'd like them to be, and the jumpers and/or breadboard around the transistor will get warm (or hot).

Use thicker wire, and solder the high current connections.

4

Thanks. Here's the strand details. I use one in each ear, controlled via one TIP.

Sounds like I should:

  • solder a normal jumper wire to the TIP top post (connects to Arduino Pin 4)
  • solder thicker wire to the TIP middle post (connects to LED strands negative)
  • solder thicker wire to the TIP bottom post (connects to common negative, which also goes into Arduino)

And not use a breadboard at all.

Right?

Appreciate the fast replies.

LEDstrand.png

5

Larry_Tremaine:
Sounds like I should...
not use a breadboard at all.

Right?

That's the way I see it.