## Mophie PowerStation 5X

PWRSTION-10K-ALM MOPPS10KSLVV1 39.56Wh 10,000mAh Mophie PowerStation 5X

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# 2 x 4.5 volt units, and 1 x 9 volt DC power block

As the title says, I have two 4.5 volt LED light strips (each one originally ran off 3x1.5 AA batteries). Can I use one 9 volt AC-to-DC power supply (wall wart type) to power these?

If so, do I wire these lights in series, or parallel?

Thanks!

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Score 0

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You do need to know what LED's you have and how many. Typical values for LEDs are:

Red LED: 2V 15mA

Green LED: 2.1V 20mA

Blue LED: 3.2V 25mA

While LED: 3.2V 25mA

To figure out the size of the resistor use R = (V1 - V2) / I

R=(9-4.5)/I

(9-4.5)/0.02

4.5/0.02=225 ohms (easiest available resistor would b a 230ohm resistor)

Or you can use this calculatorto figure out how to wire it by using resistors.

Score 2

the resistor values given are quite not right.in series connection , the current through one led passes through the rest of the leds.so the current stays constant.[inthis case 20mA.

@renre thank you and it has been corrected

Remember that a resistor will dissipate some power, perhaps as much as your LED strip [constant 20mA current x (9-4.5)V=90mW; 1/8W should be fine] so always check the power rating of a resistor before finishing your design.

It's worth trying both strips in series, (+)-[strip]-(-)(+)-[strip]-(-); if they have some internal current regulation, you may not need more at all.

Connection will be in series

Score 1

Would you anticipate problems doing this? Would it be better to use TWO separate power supplies, 4.5 volts each?

No as long as you connect in the series no problems ..... resistance = V/Amps if you want can add a resistor , considering current 40ma for 2 led strips ....