Hi! I am using a 12V 15A power supply to power up my sim800 gsm/gprs shield which it prefers 12 V 2A to work and be using on my project. Is this okay or do I need something on this? Thanks a lot!

More amps is no problem. The circuit will only draw as many as it needs. Voltage is always the one to watch for and is often more critical. Always better to over specify the amps required so you should be fine. Your post was MOVED to its current location as it is more suitable. Could you also take a few moments to Learn How To Use The Forum. Other general help and troubleshooting advice can be found here. It will help you get the best out of the forum in the future.

The only danger is if you do "something wrong" like create a short and get "excess current". 15 Amps is enough to burn-up small connecting wires or melt a breadboard, or to burn small traces off of a PC board. etc. (Something like a reversed IC or over-voltaged IC will probably burn-up at 2A anyway.) ...Here in the U.S. a typical wall outlet is rated at 120V and 15 Amps. 120 Volts is always present but current flows only when something is plugged-in and turned-on. If you plug-in a little night light less than 1A flows. A hair drier or toaster might take 12A and if you plug-in a hair drier and toaster at the same time (and turn them on) you'll get more than 15A until the circuit breaker blows and then the voltage drops to zero.

As long as the current drawn by things you are running off one source of power add up to less than the current available, you are OK: [image] Seven is the limit in Hootersville, so if, for example, you're running the frying pan and the mixer, you can add the coffee pot OR the can opener, but not both. HTH a7

Many power supplies of that size have a small pot that allows you to set the voltage in a relative narrow range. Try that and see if you can get it down to 12V, the closer the better and it only takes a small screw drive and multimeter.

[image] gilshultz: see if you can get it down to 12V, the closer the better... If OP means a DFRobot GSM shield, then don't worry. The SIM800 module runs on 4volt, but the shield has a built-in DC/DC converter that accepts 7-23volt according to the specs. Leo..

Hello guys, I managed to power up my gsm shield using the 12V 15A power supply. One thing that bothers me the most is when I need to pin up the ground from the gsm shield to my Arduino Uno. Will it make any problem/s with that? Thank you very much to all!

[image] Common ground and why you need one General Electronics A common mistake for people new to electronics is to have 2 circuits fed from different power supplies with signals passing between the circuits, but with the grounds not connected. This leads to questions asking why the project doesn't work. You don't have to spend long reading the questions on this forum to see this is asked often. Here I attempt to explain the problem and why it matters to connect the grounds. Note that in all of the schematics that follow I have used a battery as a power sup… That should give you some ideas about grounding.

12v 15A power supply to sim800 gsm shield(12v 2A)?

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Ballscrewbob July 1, 2021, 3:56am 8

That should give you some ideas about grounding.

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12v 15A power supply to sim800 gsm shield(12v 2A)?

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