# Required voltage and amperage for 3 circuits

I'm trying to make a Bluetooth speaker set that also has some lights.

I got the amp from eBay which runs at 12v 1amp, the led strips are also 12v and I want to control them from the Ardunio nano.

I'm trying to take some samples from the audio input into the amp to set the led strip design.

How much voltage do I need to run all 3 circuits at the same time. I'm a little unsure when it comes to calculating voltage and amperage and I'm still waiting for some parts to arrive.

At the moment my circuit runs 4 lm7805cv voltage limiters to convert the 12v from the LEDs to the Ardunio pins and 1 of those is to power the Ardunio directly.

So can anyone help me with understanding voltage without a 10 hour course ?

AceScottie:
At the moment my circuit runs 4 lm7805cv voltage limiters to convert the 12v from the LEDs to the Ardunio pins and 1 of those is to power the Ardunio directly.

So were do the other three voltage regulators connect to?
Could you draw a circuit diagram of how you have connected this.
Or post a picture.

Since you have a 12volt LED strip, you need a 12volt supply.
Current requirement depends on the type and length of LED strip.
Not sure what the voltage requirement is for the "bluetooth amp" or "lamp".
Leo..

Led strip requires 12v and has 1 power and 3 GND each GND has a voltage regulator to make sure it's not over 5v back to the Ardunio.

Amp is also 12v

Will post schematic when I get back home tonight

Ok so here is the schematic for the dirve.

J2 pin 1 = Power
J2 pin 2 = GND

the led array is a 4 wire setup. 1 Power 3 GND.

Each U1 is a lm7805CV voltage regulator.

Some of the schematic was cloned from different forum posts explaining how to scale the voltage down from 12V to 5V.

Cloning sometimes produces an animal with three heads.
This circuit is such a failure.
An 78xx can only be used as power supply.

You most likely don't need a regulator.
There is already one (smaller version) mounted on the Micro board.
The RAW supply input is rated from 6-20volt.
12volt can be directly connected to that RAW pin (! not the VCC pin !).

I assume you want to drive a LED strip.
You need three logic mosfets to drive the three colours.
Three 220ohm resistors between Arduino output pin and gates.
And three 10k resistors from Arduino outputs to ground.

What is the length of the strip.
There are many types. Post a link.
Leo..

Hi,

What is your electronics, programming, arduino, hardware experience?

Sorry but you will definitely let the smoke out if you use that circuit.
How do you expect the Pro to control the LEDs?
Please place labels on your two sockets to identify what the pins are, eg 12V , gnd.

Tom.....
Can I suggest you;
Gargle Ohms law
Gargle LED basic circuits
Gargle LM7805 voltage regulator basics

Ok thanks for all the advice, I see i must of misinterpreted a mosfet for a voltage regulator (they kinda look the same).

as for experience, Arduino: little, Programming: quite a bit, Electronics:little, Tinkering: enough to fill 5 lifetimes .

Re worked the Design quite a bit now got 1 12v to 5v regulator to power the Arduino. (using a Nano which has no RAW pin only VIN and 5+ and dont know the rules on the VIN)

I am taking the 10k resister value from a tutorial i found (Jerome Bernard: RGB Led Strip controlled by an Arduino).

The LED Strip is 5m long however i will be cutting it down a bit after i get a box and stuff for the speakers.
LED: http://www.ebay.co.uk/itm/261526895309?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

You just don't get it.
It is the gate of the FET that should be connected to the Arduino pins. Correct that and it is still not what you are trying to copy.
Try again.

AceScottie:
Re worked the Design quite a bit now got 1 12v to 5v regulator to power the Arduino. (using a Nano which has no RAW pin only VIN and 5+ and dont know the rules on the VIN)

Get rid of the 7805 regulator, and put 12volt directly on the Vin (= raw) pin.

It seems Jerome didn’t know what he was doing either. Red and green/blue are connected differently.

10k from Arduino pin to ground.
220ohm from Arduino pin to gate.
Source to ground.
Drains to LED RGB strip.
Led strip common anode to 12volt.
Leo…

Sorry it took so long to reply (I have Uni and stuff). Got my AMP today and it works and is pretty decent.
Remade the diagram a bit and as a quick note; MOSFET pinout assumed 1=Source 2=Gate, 3=Drain.

If you would like to know what my goal is, I hope to create a Bluetooth speaker set that flashes in sync with the music and can run off a few batteries or a DC plug.

12volt connected to VCC will smoke the Nano. Connect 12volt to Vin....

Vin = raw = unregulated input = 7-12volt.

The rest of the circuit seems ok.

The listed fet is too small for a LED strip.
Leo..

yea i couldn't find the right part in the library. These are the MOSFETs ill be using http://www.ebay.co.uk/itm/STP16NF06L-Mosfet-N-Ch-60V-16A-To220-STMICROELECTRONICS-/191500442912?hash=item2c9650dd20

Also the Marked VCC pin is actually the VIN pin on the Nano (I had to build the part myself so got a few pins mixed up and named some wrong)