Hello
i bought MB102 Power Supply Module from Here ,but i have faced weird problem; i hooked up an LED and 1k resistor to arduino output (high) and to the ground of that power supply, the LED doesn't light up and current was 0uA !!! the LED lights only if i hook up the ground of the arduino to the ground of power Supply.
i took this results too :
voltage between Power Supply positive pin and arduino ground = 8.46v
voltage between Power Supply negative pin and arduino ground = 3.546v
voltage between arduino output and PS negative pin = -0.37v
voltage between arduino output and PS positive pin = 0.044v
Can someone explains to me the results ? it's probably something stupid and basic electronics problem.
thank you.
And maybe I (deliberately) didn't explain myself well to match.
An electrical circuit involves a complete circular path which can be traced from any one point through the power source and connected components including the "load" back to the same point.
Since you have given no information as to what is actually powering your Arduino or your MB102 "Power Supply", it is completely obscure, but it seems probable that you have two independent power supplies, probably "plug packs" (American: "Wall warts") connected to the two different devices, or are powering your Arduino from the USB output of a laptop or PC - or a "phone charger". Connecting a LED from one terminal of one power supply to another terminal of an entirely separate power supply which is otherwise not connected in any way does not constitute a circuit.
Paul__B:
And maybe I (deliberately) didn't explain myself well to match.
An electrical circuit involves a complete circular path which can be traced from any one point through the power source and connected components including the "load" back to the same point.
Since you have given no information as to what is actually powering your Arduino or your MB102 "Power Supply", it is completely obscure, but it seems probable that you have two independent power supplies, probably "plug packs" (American: "Wall warts") connected to the two different devices, or are powering your Arduino from the USB output of a laptop or PC - or a "phone charger". Connecting a LED from one terminal of one power supply to another terminal of an entirely separate power supply which is otherwise not connected in any way does not constitute a circuit.
That's make sense now.Thank you.
indeed they are two independent power supplies (one from PC USB and other from 9v battery).
is it safe for arduino and my laptop USB port to keep powering from these two independent power supplies and connect the arduino ground to MB102 PS Module ground ?
IVDZ:
is it safe for Arduino and my laptop USB port to keep powering from these two independent power supplies and connect the Arduino ground to MB102 PS Module ground ?
In order to interconnect devices or modules, it is in the vast majority of cases, not safe but essential to connect the ground of each device to the ground of any other device to which it connects, in order for it to function.
Occasionally, you instead need to connect the Vcc - supply voltage - of one device to another module, but almost never the positive of two power supplies together.
Paul__B:
I/ we really hope that when you refer to a "9V battery", you mean one of these loaded with AA cells:
and not one of these:
In order to interconnect devices or modules, it is in the vast majority of cases, not safe but essential to connect the ground of each device to the ground of any other device to which it connects, in order for it to function.
Occasionally, you instead need to connect the Vcc - supply voltage - of one device to another module, but almost never the positive of two power supplies together.
i got it . now i'm powering my breadboard with just arduino.
and yes i used the battery in the second picture , was that wrong ?
. now i'm powering my breadboard with just arduino.