basic electronics question about power

Got a basic electronics question I have a power source that outputs 5vs I need it too power different things..

an ardunio board Some leds which for the sake of the example are in series and pull 4 volts And an mp3 player that needs 3.7 volts

so how would I wire this all up?

[ the symbol for the volt is V, not v. It doesn't take a plural, so 5V, not 5vs ]

For LEDs you'd typically use a series resistor to limit the current to a safe value for the LED - normally small LEDs are rated for 20mA or so.

For powering that MP3 player you'd probably need a voltage regulator to drop from 5V down to 3.7V. (Which is an unusual voltage to drop down to, 3.3V is much more common) You might want to check if the MP3 player specs say the minimum and maximum voltage it accepts.

Or use a 3.7V lithium battery to power the MP3 player and a boost DC-DC converter to generate 5V from that.

had a look I again and it was 3.7 I dont know why I thought 3.3 I also need to run an amp off the circuit but its a 5v amp

so effectively I have a resistor, voltage regulator, amp and ardunio player running on parallel lines with there ground all joining up as well

is this correct ?

You didn’t think 3.3V, I said that voltage regulators come with that as a standard output voltage.

You’ll need to find out what the current drain is for all the devices and ensure the 5V supply is
able to handle that much current.

Fair enough but assuming the answer is it can deal with the current I am all good

I assume if it cant I need to get a better power supply?