Hello,
I am building a music player project using the VS1053 Breakout, 3.7W Stereo Amp, and an Arduino Mega. I was curious what the current draw of the 3.7W Stereo Amp (MAX98306) is while playing? The learning guide suggests powering it from an external battery pack, but I was wondering whether this is due to current needs or just a way to make the project portable. Does the Mega provide enough current on the 5V pin to drive the breakout and amp with two 3 Ohm speakers?
I will be driving the Arduino with a 9V power supply through the vin pin. The project does include a LM7805 regulator to convert the 9V to a regulated 5V, but that regulator is already being used to drive a hobby motor with a current draw in the 200-300mA range so want to limit what I use that regulated 5V supply for if possible.
Arduino VS1053 Breakout + 3.7W Stereo Amp
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- tclambert00
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- rpiloverbd
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Re: Arduino VS1053 Breakout + 3.7W Stereo Amp
I used 2 rechargeable lithium-ion batteries(8.4V in total) in series to power up an Arduino UNO and a VS1053B music shield. I think an ordinary 9V battery will not be able to supply sufficient current to your project.
- tclambert00
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Re: Arduino VS1053 Breakout + 3.7W Stereo Amp
Yes, the plan is to power it with a 9V 1A power supply, not a regular 9V battery. What I'm really curious about is whether I can use the mega 5V pin to power the VS1053 and amp or if I'll need an external supply for that.
- adafruit_support_mike
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Re: Arduino VS1053 Breakout + 3.7W Stereo Amp
The current load depends on the speakers you use.
The power equation is P=IV and Ohm's Law is V=IR. We can combine them to get P=I(IR) and P=(V/R)V. Rearranging those to get power and current gives us:
V = sqrt(PR)
I = sqrt(P/R)
Based on those, a 4-Ohm speaker operating at 3.7W would use about 960mA @ 3.8V
A 3-Ohm speaker would use about 1.1A @ 3.3V
An 8-Ohm speaker would use about 680mA @ 5.4V
The power equation is P=IV and Ohm's Law is V=IR. We can combine them to get P=I(IR) and P=(V/R)V. Rearranging those to get power and current gives us:
V = sqrt(PR)
I = sqrt(P/R)
Based on those, a 4-Ohm speaker operating at 3.7W would use about 960mA @ 3.8V
A 3-Ohm speaker would use about 1.1A @ 3.3V
An 8-Ohm speaker would use about 680mA @ 5.4V
- tclambert00
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Re: Arduino VS1053 Breakout + 3.7W Stereo Amp
Got it. So if I have two 4-Ohm 3W speakers and the 3.7W amp is powered from an external 5V supply, would each speaker be drawing 866mA?adafruit_support_mike wrote:
The power equation is P=IV and Ohm's Law is V=IR. We can combine them to get P=I(IR) and P=(V/R)V. Rearranging those to get power and current gives us:
V = sqrt(PR)
I = sqrt(P/R)
- adafruit_support_mike
- Posts: 67446
- Joined: Thu Feb 11, 2010 2:51 pm
Please be positive and constructive with your questions and comments.