JQ-D015BT -- Power Supply

The JQ-D015BT module has an on-board voltage regulator that can accept a wide range of input voltages ranging from 5 V to 15 V (maximum). The 78M05 voltage regulator in a DPAK-3 package produces 5 V, and supply up to 500 mA of current with heat sinking. For adequate line regulation, the minimum voltage should be 7.0 V. Due to this on-board voltage regulator; the manufacturers recommend using JQ-D015BT in a car or motorcycle that has a 12 V electrical system. Just make sure there is an in-line fuse for safety. Note that not all MP3 player Bluetooth modules have an onboard voltage regulator and therefore you should check yours first to see if it has this component before you decide to power it.

An advantage of having a module that operates on 12 V is that if you are building homemade Bluetooth speakers, then you will likely need a power amplifier, and many of them operate on 12 V as well. Hence, it can greatly simplify your power supply design as both can draw power from the same voltage rail.

If you wish to power the module on 5 V, then they have another version of the module that does not have the voltage regulator. For this one, you will require a 5 V power source. I have seen many projects where experts have used the JQ-D015BT module (12 V version) with a large external 5 V regulated power supply circuit, which is unnecessary. This module will work fine on 6 V, 9 V, and 12 V DC power supply due to the onboard voltage regulator.

This particular board also has a protection diode D1 for voltage reversals, which is very intelligent of the manufacturer to place considering that this might be in the hands of amateurs and hobbyists of disparately varying abilities.

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