- #1
Alex Hughes
- 54
- 13
So I'm fairly new to electronics. I took physics 2 in college and thought I'd give the hobby a try. I started with a very basic circuit. Just a power supply connected to a light-bulb. However, as simple as it was, I had several questions when taking the reading of my circuit with a multi-meter.
Question 1:
When I hook up my multi-meter as shown (I'm aware this isn't a good way to do it I'm just experimenting), I get a reading of 0.64A when I set it to measure current but the light-bulb goes out. Now I'm aware this is probably because the circuit is skipping over my light-bulb and just going through my multi-meter, but aren't the terminals to the light-bulb still in contact with the wire? Why would the current choose to go through the path of the meter and not through the light-bulb?
Question 2:
Now this time, I set my multi-meter to read voltage and it gave me a reading of around 3V which is what my power supply is set at. However, the light-bulb does not come on. Now I don't see how there is a voltage drop in the areas I connected my meter to. Does the meter somehow drop the voltage down when the current goes into it and that's why my light-bulb doesn't come on, yet I get a voltage reading? I'm so confused.
Question 3: (Last Question)
Ok, so in this circuit I hooked up my ammeter two different ways. The first reading gave me a current of 0.64A at a constant voltage from my power supply of around 3V. The second circuit also gave me a current reading but at 0.74A. The second way also caused my power supply to switch from C.V mode to C.C mode instantly. I understand that it probably reads more amps because the light-bulb is not drawing power from it, but why is my power supply making a slight hissing noise and switching to CC mode when I do this?
I think a lot of this would make more sense if somebody could describe to me exactly how a multi-meter works, and how it changes how it reads things when it goes from measuring voltage, to current, to resistance. Sorry, I'm a perfectionist and these aren't making much sense to me. Would love some detailed feedback. Thanks!
Question 1:
When I hook up my multi-meter as shown (I'm aware this isn't a good way to do it I'm just experimenting), I get a reading of 0.64A when I set it to measure current but the light-bulb goes out. Now I'm aware this is probably because the circuit is skipping over my light-bulb and just going through my multi-meter, but aren't the terminals to the light-bulb still in contact with the wire? Why would the current choose to go through the path of the meter and not through the light-bulb?
Question 2:
Now this time, I set my multi-meter to read voltage and it gave me a reading of around 3V which is what my power supply is set at. However, the light-bulb does not come on. Now I don't see how there is a voltage drop in the areas I connected my meter to. Does the meter somehow drop the voltage down when the current goes into it and that's why my light-bulb doesn't come on, yet I get a voltage reading? I'm so confused.
Question 3: (Last Question)
Ok, so in this circuit I hooked up my ammeter two different ways. The first reading gave me a current of 0.64A at a constant voltage from my power supply of around 3V. The second circuit also gave me a current reading but at 0.74A. The second way also caused my power supply to switch from C.V mode to C.C mode instantly. I understand that it probably reads more amps because the light-bulb is not drawing power from it, but why is my power supply making a slight hissing noise and switching to CC mode when I do this?
I think a lot of this would make more sense if somebody could describe to me exactly how a multi-meter works, and how it changes how it reads things when it goes from measuring voltage, to current, to resistance. Sorry, I'm a perfectionist and these aren't making much sense to me. Would love some detailed feedback. Thanks!
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