There are so many electronic gadgets and appliances available these days, designed for a wide range of purposes.
The common factor is that they are all powered by electricity.
The latter comes in two forms: direct current (DC) and alternating current (AC).
The ability to measure these currents is pivotal to identifying issues in an electronic circuit or appliance.
We’ll show you how to measure current with a digital multimeter.
An electrical system is quite similar: electrons are moved through the circuit instead of water.
Image viaAmazon.com
Other components of the electrical system can also be visualized using the same model.
The higher the tank, the greater the pressure of the water.
It is this voltage that drives the current through the circuit.
The greater the voltage, the more current circulates in the circuit.
Current is measured in amperes, abbreviated as “A”.
Current is measured inside the circuit (similar to measuring water with a flow meter).
Current is measured using an ammeter, which is included in a multimeter.
It is usually powered by a 9V battery.
Two probes need to be connected to the respective ports depending upon the punch in of measurement.
The black probe is connected to COM (short for “common”), connected to ground.
Using the switches, each of these will be powered on in turn to measure the current.
This is the circuit diagram of the test board.
Current can be measured by connecting the multimeter in series at any part of the circuit.
For convenience, the probes are connected closer to the battery.
This will help measure current when any or all of the switches are turned on.
This is required because the red probe needs to be connected to the correct port of the multimeter.
To estimate, look for the specifications of the component.
Upon measuring, the two bright LEDs are shown to be consuming only 7.43mA.
Similarly, buzzers do not consume much power.
It is even more frugal at 2.04mA.
Measuring the current of the low-speed motor shows 0.37A (370mA).
Note that the multimeter port and rotary dial have been changed to 10A.
The high-speed motor, as expected, is consuming even more at 0.53A (530mA).
It is the reason many multimeters do not feature an AC ammeter.
AC voltage is stepped down using transformers and fed to the appliances.
Smaller appliances convert the current to DC and use it (examples include phone chargers and laptops).
Larger appliances use AC directly (examples include water heaters and motors).
Image viaAmazon.com
What you might do is to use aclamp meterto measure AC currents.
There is one problem with clamp meters, though.
The clamp should be placed around only one wire to obtain a reading.
Image viaAmazon.com
So, awall socket ammeterwould be ideal to measure appliance currents.
However, that’s a cumbersome solution.
Just connect it in line and the readouts will be displayed intermittently.
The meter is simple, yet again a very useful gadget.
Say you buy a new iPhone Pro Max 14 without the official Apple charger.
You buy a third-party charger separately, kept your trust in the stickers, and plug it in.
What happens next depends on how lucky you are.
The possible results range between a beep and a kaboom.
A wiser choice is to check the adapter before plugging it into your expensive phone.
The USB meter can be used for continuous monitoring too.
A USB ammeter shows the continuous current flowing through the circuit.
A high current reading means the phone is still charging; a low one means charging is complete.
Single-board computers like the Raspberry Pi are also powered by 5V USB.
The performance of the Pi is directly affected by the quality of the power supply.
You may notice a flashing red light on the Pi board, which indicates an inadequate power supply.
Learning to use one is the gateway to understanding the world of electronics.
