Realize that the multimeter is acting as a piece of wire - you've now completed the circuit, and the circuit will power on. This circuit was only pulling 1.8mA at the time of measurement, not a lot of current. Note that almost all multimeters have the same sized jacks (they're called "banana plugs") so if you're in a pinch, you can use your friend's probes. These alligator clip probes can come in handy.
#Multisim multimeter free
While you might want to stand there and hold the probes to the system, sometimes it's easier to free up your hands. When measuring current, it's often good to watch what your system does over time, for a few seconds or minutes. We then insert the multimeter in-line so that it can measure the current as it "flows" through to the multimeter into the bread board.įor these pictures, we cheated and used alligator clips. This effectively "breaks" power to the circuit. Said another way, pull out the VCC wire going to the resistor, add a wire where that wire was connected, and then probe from the power pin on the power supply to the resistor. As mentioned, we'll need to physically interrupt the circuit to measure the current. The first thing we'll need is an extra piece of wire. To demonstrate this, we'll use the same circuit we used in the measuring voltage section. Where voltage is measure by poking at VCC and GND (in parallel), to measure current you have to physically interrupt the flow of current and put the meter in-line. It's tricky because you have to measure current in series. Reading current is one of the trickiest and most insightful readings in the world of embedded electronics. This allows for different types of probes to be used. Any probe with a banana plug will work with this meter. The probes have a banana type connector on the end that plugs into the multimeter. This port allows the measurement of current (up to 200mA), voltage (V), and resistance (Ω). mAVΩ is the port that the red probe is conventionally plugged in to. 10A is the special port used when measuring large currents (greater than 200mA). The COM probe is conventionally black but there is no difference between the red probe and black probe other than color. COM stands for common and is almost always connected to Ground or ‘-’ of a circuit. Two probes are plugged into two of the ports on the front of the unit. The selection knob allows the user to set the multimeter to read different things such as milliamps (mA) of current, voltage (V) and resistance (Ω). A few multimeters have illuminated displays for better viewing in low light situations. The display usually has four digits and the ability to display a negative sign.