Objective: I'm new to electricity and trying to convert my mirror integrated with LED work with a power bank. I need to find how much voltage and current is needed to make it work.

How can I measure the voltage and current it is using from the wall socket? I searched that using a multi-meter:

  • Voltage: Connect it in parallel and measure the voltage
  • Current: Connect it in series and measure the amperage

However, since wall outlet is AC and probably the light is DC, how can I actually measure it? For voltage there is no positive (+) or negative (-) from the power source to be able to do it in parallel. And for amperes, where am I supposed to put the probes?

PS: If there is any other device simpler to use that can help me with other than multi-meter, please mention it. Thanks.

  • \$\begingroup\$ Does the mirror plug directly into the wall outlet, or does it have a "walll wart" power supply (DC power supply integrated into the plug) or a power supply in the cord, like many notebook computers? Is there a label on the mirror specifying the required voltage and current or power? \$\endgroup\$ – Peter Bennett Dec 3 '19 at 23:02
  • \$\begingroup\$ @PeterBennett unfortunately there is no label or that would've made my life 10x easier. It does not have a wall wart power supply. It just has cables sticking out of it which must be connected the wall directly. I made it into a plug and just plug it into the socket. \$\endgroup\$ – F.A Dec 3 '19 at 23:11
  • \$\begingroup\$ If the mirror plugs directly into an AC outlet, then it requires 120 V AC (or 240 V AC, depending on where you are). You will not be able to run it from a DC power bank, unless you are willing to dig inside it - even then, it will likely require a much higher voltage than a power bank provides. \$\endgroup\$ – Peter Bennett Dec 4 '19 at 0:05
  • \$\begingroup\$ @F.A If you are new to electricity, it's probably better if you can find someone local to help you out. If they are willing, you can also learn as you watch them go through various steps to figure out a solution and implement it. While this is probably not the best first project to work on by yourself it certainly may be a very good first project to learn from as someone else helps you through it. \$\endgroup\$ – jonk Dec 4 '19 at 1:25
  • \$\begingroup\$ Before you can adapt one voltage to another you must learn to find the voltages in the fine print or measure it with a DMM or find something else. \$\endgroup\$ – Tony Stewart Sunnyskyguy EE75 Dec 4 '19 at 4:50

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