... for beginners who are new to RF like me, and even the cheapest RF power Meters cost hundreds of RMB. For electronics enthusiasts who follow the principle of "spend when you should, save when you can", DIYing an RF power Meter is a great alternative. The first step WAs to define the functions and design the hardware circuit. To test RF power, a chip called a detector is required. I had not found a suitable option for a long time as it WAs my first time working with an RF detector, until I saw the power detection module on the E25-C test baseboard, which use ...

Definetly not, Dont switch to amps or move the red lead to the A/10A jack while your probes are on a live circuit. In A mode the Meter is basically a short; flipping to it or probing voltage with the lead in A can blow the fuse, make an arc, or worse. Set the Meter and leads with power off, break the circuit, insert the Meter in series, then power up. For mains, use a clamp Meter; for 12 V high-current systems be extra cautious or use a clamp/shunt. And always move the red lead back to V when you’re done to avoid the classic “next-time short.”

Not quite—a 6000-count Meter doesn’t extend the 2V range to 5.999V. The range is fixed by the multimeter, not the count. In the 2V range, both 2000- and 6000-count Meters typically max out at 1.999V. A 6000-count Meter would show up to 5.999V only if it's on a 6V range, not 2V. So, a higher count means better resolution, but the voltage range itself stays the same unless the Meter has a higher range setting.

This usually happens due to the high sensitivity of the multimeter’s continuity mode. Some Meters are designed to beep even with very low resistance, which means slight contact, moisture, or even nearby conductive surfaces can trigger a false beep. However, that's not the only cause. Sometimes, while testing components like Semiconductors or capacitors, residual charge or leakage paths within the component can also cause the Meter to falsely detect continuity. In such cases, the beep doesn't necessarily indicate a true short—it could just be the Meter reacting to a small voltage or current still present in the circuit.

Yes, the 0.6 V drop you’re seeing is the Meter’s burden voltage, which is the voltage lost across the DMM when it measures current. In mA mode, the Meter places a small internal shunt resistor (and often a fuse or protection components) in series with your circuit to sense current, and this resistance causes a voltage drop equal to V=I×Rmeter​. For example, a 0.6 V drop at 60 mA means the Meter adds about 10 Ω in series, which can significantly affect low-voltage circuits by reducing the actual voltage reaching your load. To minimize this, you can use an external low-value shunt resistor and measure the voltage across it with the DMM in voltage mode, then calculate current using I=V/RI = V/RI=V/R. Alternatively, use a dedicated low-burden current sense amplifier or sensor such as the INA219, a DC clamp probe that measures current without inserting resistance, or the Meter’s 10 A input (which usually has much lower internal resistance) if the current is within safe limits. These methods help keep the measurement accurate without disturbing the circuit’s operating voltage.

... of wire—it has very low resistance. If you try to connect it across a live circuit (like you would for voltage), you're basically shorting the power source, and that can result in Blown fuse in the Meter (if you're lucky), Arcs or sparks. So, If you dont WAnt that Always power off the circuit before measuring current. Break the circuit and insert the Meter in series, making sure the probes are in the correct ports—especially the high current port if you're measuring above ~200mA. Once everything's connected, power on the circuit, take your reading, and t ...

Hi everyone, While checking continuity with my multimeter, I sometimes get beeping sounds even when the probes aren’t actually touching the wires.It seems like a false reading.Could this be due to stray capacitance, interference, or a faulty Meter?

I’ve seen WArnings about using the current (amp) setting on a multimeter, and I WAnt to be cautious. I understand that to measure current, the Meter has to be placed in series with the load. But I’m unsure about the risks involved when doing this on a live circuit, especially with higher voltages like AC mains or even 12V DC systems with decent current. Is it safe to switch to the amp mode while the circuit is powered?

Yes, if you measure current like voltage (in parallel), you can short the circuit and blow the multimeter fuse, or worse, damage it. Also, if the probe is left in the current port and you try to measure voltage, it creates a short path and can seriously damage the Meter or the circuit. Always switch the probe back to the voltage port and check your dial setting before measuring.

I know that shift registers like the 74HC595 can be daisy-chained to expand outputs, but I’m wondering where the practical limit lies. Is the limit mainly due to propagation delay and timing issues, or do factors like power consumption, loading on the data and clock lines, and signal integrity also become major concerns as the chain gets longer? Are there any general guidelines (such as maximum number of devices or Total outputs) before performance or reliability starts to drop? I’d be interested to hear from anyone who has pushed the number of chained shift registers in a real project.

... us a Total of 12 state machines. 4 more than the original Security features Price- just $5 1 more ADC(total 4) and 8 more PWM(total 24) then the original Pico. Supports C/C++, Arduino IDE, Circuitpython and Micropython Now Disadvantages: Still no USB-C No reset button It would have been better if there WAs a built-in WiFi chip(link Pico W) if they WAnt to compete with ESP32. But of course, they will sell it separately as a new board and call it Pico 2W. Please add to this if you think there are more. Also, will publish an in-depth article on Pico 2 ...

... gives inaccurate results. 2. Discharge the capacitor safely: 3. Use a resistor (e.g., 1kΩ, 1W) across the leads. 4. Avoid shorting large electrolytics directly — they can spark or get damaged. 5. Set your multimeter to capacitance mode (⏀). 6. Connect the probes to the capacitor leads. Polarity doesn't matter for film or ceramic caps; for electrolytics, follow Meter instructions. 7. WAit a few seconds for the reading to stabilize — especially for high-value caps. Hope this helps!

Yes, definitely discharge the capacitor first — especially if it's a high-voltage one. A charged cap can damage your multimeter or give you completely wrong readings. To discharge it, you can short the leads using a resistor (like 1kΩ or 10kΩ), or a screwdriver with an insulated handle if it's a small electrolytic (nothing high voltage though — not safe). Also, for accurate readings: Take the capacitor out of the circuit if you can. In-circuit measurements are often wrong because of parallel components. Let the multimeter settle for a few seconds, especially with large caps. Make sure your test leads are making good contact. If your Meter has a "zero" or "rel" mode, use that to cancel out stray capacitance from the probes. And keep in mind, these DMM readings are just a ballpark — they won’t tell you if the cap has high ESR or leakage. For that, you'd need an ESR Meter.