ANENG PN129 is an open jaw clamp meter (sometimes called an open fork meter or clamp-on tester) is a handheld electrical testing tool used to measure current in a conductor without breaking the circuit. Unlike traditional clamp meters that have a hinged jaw you open and close around a wire, an open jaw clamp meter has a fixed U-shaped or fork-shaped opening. You simply slide the conductor into the open fork, and the meter uses a magnetic field sensor to measure the current flowing through it. This is useful for quick current checks without disturbing wiring. U-shaped clamp design (≈12 mm opening) that allows easy, non-contact measurement of current on single conductors.

Measurement Capabilities of ANENG PN129

AC/DC Current: Up to 100 A
AC/DC Voltage: Up to 600 V
Resistance: Up to 20 MΩ

This meter can make true RMS (TRMS) measurements with 4000 counts for added precision. ´

In addition to numeric measurements, this meter has continuity Test (with buzzer), NCV (non-contact voltage detection), data hold, auto power-off (approx. 15 mins), backlit LCD, and even a built-in flashlight for dim environments.

ANENG PN129 is compact size (160 × 37 × 26 mm) and lightweight (~68 g). The meter is safety rated CAT III 600 V for safe electrical use in wide variety of electrical circuits. Rated CAT III 600 means that it is suitable for many household and light industrial applications.

Supplied accessories (normal version): includes test leads, multiple adapters (alligator clips, probes), batteries, and a storage bag.

Videos:

ANENG PN130 Clamp Meter,4000 Counts,Auto Range,NCV Non-Contact Voltage Detection

ANENG PN129 Digital Clamp Meter 600V 100A Multimeter with LCD Backlit Display Review

ANENG PN129 U-Type Current Clamp Meter,Automatic Range 4000 Counts,Measure Automotive DC Current

ANENG PN129 Digital Clamp Meter 600V 100A Multimeter with LCD Backlit Display Review

ANENG PN129 Digital Clamp Meter 600V 100A Multimeter with LCD Backlit Display Review

ANENG PN129 U-Type Current Clamp Meter,Automatic Range 4000 Counts,Measure Automotive DC Current

Measurement features:

For AC current measurement, no need to break the line, non-contact measurement AC current. Just power on the meter from power button it enters to AUTO mode, where it can measure AC current, DC voltage, AC voltage, DC voltage and resistance (with beeper for low resistance).

For DC current measurement press “A–NCV” once to enter DC current. In this mode you need to often use ZERO button to calibrate out the outside magnetic fields effect from the measurement.

When you press “A–NCV” second time, the meter goes to AC current measurement mode.

NCV induction detection, press “A–NCV” once more to enter NCV and it is detected. The display will show you EF and NCV. When there is considerable AC voltage near the tip of the u-shaped jaw tips an alarm will sound and display will show ——-.

On the side of the meter there is a Hold/lamp button. A short press will enable and disable data hold. When you press a little longer, the built in LED flashlight and the display back light.

When measuring the current (AC or DC), you need to have the wire close to the innermost end of the u-shaped jaw to get the best accuracy. The U-shaped open-jaw measurement works well for AC with quite good accuracy as long as you can get the wire to the right position (deep enough).

For DC measurement you need to note that there could be error in the result because of external magnetic fields can affect the current measurement. Turning the meter to different directions can easily cause readings up to few hundred mA without any wire nearby. To do reliable DC measurement, you should move the the meter to near the measuring location, then press ZERO and then move the meter (without turning it) to the measurement position. This external magnetic field affecting to measurement is typical (more or less) to all DC capable non contact meter, those U-shaped open jaw meter being considerably more sensitive to external magnetic fields that clamp meters (that are less sensitive). Please also note that magnetic tools placed near the U-shaped measurement location can cause measurement error. That’s typical to this type of instruments, and not a flaw in the PN129.

What is inside meter:

ANENG PN129 PN130 DC CURRENT U CLAMP METER
This video has teardown of model PN130 meter (version with rechargeable battery) starting at around 12:00

The ANENG PN129 is a budget-friendly multimeter that is relatively well-built for its price range. The PN129 has a straightforward design, with no components on the back of the PCB and no through-hole components. The component count is minimal, reflecting its low cost and intended basic functionality. Given its lack of moving parts and relatively robust build, it should be reasonably durable for general use in a toolbox.

The measurement principle for current measurement is that when electricity flows through a conductor, it creates a magnetic field around it. Inside the jaws, there’s a sensor (possibly Hall effect sensor) that detects this magnetic field. The sensor converts the magnetic field strength into a voltage signal, which is then processed by the meter’s circuitry to display the current value.

Pros:

Handy U-clamp design for fast, non-invasive current checks.
Wide measurement ranges (up to 100 A and 600 V).
Convenient extras: NCV, flashlight, auto features, data hold.
The ANENG PN129 is a budget-friendly multimeter, and while it may not be a precision instrument, it’s generally considered a decent value for its price.
Continuity and voltage measurement works well.

Considerations:

As a budget-friendly multifunction device, it may not match standalone tools in professional-grade accuracy or ruggedness or measurement features.
The fork-style current “clamp” is not as accurate as a closing-style clamp: Current measurement is sensitive to wire position inside U clamp, so does not always feel reliable (especially in DC measurement). If you need very good accuracy, consider buying a closing clamp meter instead.

Result:

Not bad for the price point. This meter costs around 30 Euros in Amazon and price 10-20 Euros in AliExpress, Temu, Banggood.

iLOQ is a smart-locking solutions from Finland. iLOQ’s smart-locking solution promises secure, convenient and flexible access with the lowest lifecycle costs, administration and environmental impact. Since iLOQ’s inception, more than 20 years ago, the lock concept has changed traditional locking solutions. iLOQ’s business where all started is battery-free and wire-free locks – No batteries, electricity source or internet connection are needed. They promise fast installation, reliable operation (even in a power outage) and no maintenance costs. Nowadays iLOQ offers also keyless, smartphone-based solutions. iLOQ’s smartphone-based cylinders are opened using an NFC-enabled smartphone running iLOQ’s app.

Nowadays their product selection has also other types of locks. They seem like a nice system for property managers. iLOQ is a https://www.iloq.com/en/insights/from-lock-evolution-to-smart-locking-revolution/”>digital locking system where the energy required to open the electronic lock is generated by the movement of the key into the lock cavity.

iLOQ self-powered digital lock cylinder The iLOQ lock cylinder has a completely self-powered digital key recognition and needs no batteries or cables. Standard size, compatible with international escutcheons and lock cases. Access rights are programmed into the key. So there is no need to program the locks. All keys are mechanically identical. Access rights are programmed into the key and can be flexibly changed. The programming and management of access rights to keys and locks can be done via a program that operates over the internet.

iLoq’s self-powered electronic locks eliminate the need for batteries or external power sources by harvesting energy from the key insertion or NFC interaction. The key or mobile device (with NFC) provides the mechanical or electrical energy to power the lock’s electronics and mechanisms, allowing it to function.

iLoq – self-power generating electronic lock teardown EEVblog article says that iLoq works by generating the power from the key push-in motion. It has SHA encryption which is taken from the key using 1-wire protocol. The lock electronics works by generating the power from the key push-in motion. The lock is opened using the same motor that generates the power (the motor actuates only a tiny motion to unlock). For information on keys take a look at FOB55S1 iLOQ Key FOB Teardown Internal Photos iLOQ O. The iLoq locks technology is protected by several patents.

Are iLoq locks safe? They had a bad vulnerability some time ago that was mentioned in Wired and Defcon. For more details take a look at videos Iloq Report on security and See a ILOQ C10S Lock Get Broken into in Under a Minute. Those vulnerabilities are supposed to be pretty much fixed now.

The internal resistance is measured by ohm (Ω). The value of internal resistance varies depending on multiple factors, such as battery size, cathode electrode, anode electrode, separator, electrolyte, temperature, and state of charge (SOC) of the battery. Internal resistance is one of the parameters that indicate a battery’s ability to carry current.

When the value of internal resistance is low, the battery is able to carry a significant amount of current. On the other hand, a battery with high internal resistance can only carry a small amount of current. One reason for measuring internal resistance is for battery maintenance: The internal resistance of a battery gradually increases as it is used. By measuring the internal resistance of the battery on a regular basis, a degraded battery can be eliminated before it becomes a problem.

To measure the battery internal resistance, a special instrument designed for this is the the best option to use. I ordered some time ago RC3563 Lithium Battery Internal Resistance Tester with 4-wire Probes to be able to measure battery internal resistance (and other low resistances).

The RC3563 battery internal resistance tester can measure internal resistance and voltage of the battery at the same time. It is very nice to get the measurement results of both resistance and voltage at the same time. RC3563 can accurately test internal resistance of your batteries with voltage range of 0-100v. RC3563 can also measure low resistance resistor values.

The measurement with RC3563 battery internal resistance tester is done using the Kelvin four-wire test clamp. Kelvin four-wire method avoids the influence of contact resistance and wire resistance (when used correctly), so accurate measurement can be performed.

Specifications:
Speed: 5 times/second
Adjustment: Correction for resistance and voltage separately
Basic accuracy:
Resistance: 0.5%
Voltage: 0.5%
Measuring ranges:
Resistance: 0.0001mΩ~200Ω
Voltage: 0.0001V~±100V direct current
Resistance ranges: 6 ranges automatic and manual
Voltage ranges: 3 ranges automatic and manual
Battery: 1 * lithium battery, 1000mAh (included)
Package size: 180 * 90 * 35mm / 7.1 * 3.5 * 1.4in
Package weight: 250g / 8.8ounce

This tester adopts intelligent control and large display, also with built-in 1000mAh lithium battery.

According to manufacturers the instrument can measure any type of batteries, including lithium batteries, lead-acid batteries, nickel-chromium batteries, dry batteries and so on. You can measure batteries of any capacity, no matter how big it is, as long as the internal resistance is within 0-200 milliohms and the voltage is within 100V. The battery’s full and depleted state will not affect the battery’s internal resistance, and can be measured, with minimal changes in internal resistance (except for defective batteries).

When I ordered the meter, I ordered few different test clamps suitable for different uses.

The RC3563 battery internal resistance tester uses AC resistance measurement method. So the tester gives Alternating Current Internal Resistance, commonly called AC Impedance or Impedance
. This tester seems to give quite accurate reading of battery internal resistance. The measurement works correctly even without battery voltage present, so RC3563 can also be used to measure the AC resistance of low-ohms resistors. Because the AC measurement method (around 1 kHz signal), this meter cannot be used to measure RC resistance of inductive components like coils, transformers or electric motors.

From: https://github.com/ludwich66/RC3563/wiki
Measurement AC Resistance DC Voltage
Accuracy Resistance 0,5% Voltage 0,5%
Range 1 µΩ – 200 Ω 1 mV – 100 V DC
Ranges 6 3
Current 2 mΩ @ 50mA
Current 20 mΩ @ 50mA
Current 200 mΩ @ 5mA
Current 2 Ω @ 5mA
Current 20 Ω @ 0,5 mA
Current 200 Ω @ 0,5 mA

Test signal frequency: AC 1 kHz

Here are some videos of RC3563:
Battery tester RC3563

High Precision Li Ion Battery Internal Resistance Tester RC3563 Close view

RC3563 battery tester – Excel and automatic measurements / PC communication (18650) video presents a way to connect the RC3563 meter to a computer and semi-automatic data reading using an excel sheet.

When I received the meter, I had some problems with the measurements. The situation was somewhat similar to RC3563 Battery Tester (inconsistent readings?) video that shows inconsistent Internal Resistance readings from meter. I originally had a similar problems that the internal resistance and voltage results were inconsistent.

I opened the meter and did some investigation.

After some investigation I found out that there were some bad soldering joints inside the meter with the two big electrolytic capacitors in the measurement circuit. After re-soldering the problem was solved.

If the meter itself is OK, but test result are unstable, it may be that the test clip is in poor contact with the battery, or the battery under test is unstable, the electrode has an oxide layer, or there is a strong magnetic field around it.

Instructions for use:
1. Short press “enter key ” to turn on.
2. Long press “enter key ” to shut down.
3. Press the “set key” to enter the setting state, then press the “select key” to select different functions, and then press the “enter key” to enter the corresponding function.
4. Enter the resistance calibration/voltage calibration state. At this time, the test line should clamp the calibration resistance or voltage, press the “set key” to select the gear to be calibrated, and then press “+” and “-” to adjust the displayed value to be equal to the calibration resistance or voltage , Press the “select key” to select “ok” or “Cancel”, and finally press the “enter key ” to decide whether to save or cancel.

Documentation links:
https://github.com/ludwich66/RC3563/blob/main/RC3563_Manual_English.pdf
https://www.scribd.com/document/660147456/RC3563-Manual-English
RC3563 RC3562A Resistance-Checker, Battery Tester, Milliohm Meter, Software, Manual

How does the battery internal resistance show in the circuit? The following picture from Hioki learning material shows an example of the internal configuration of a battery. Ideally, a battery’s internal resistance should be zero, allowing for maximum current flow without any energy loss. In reality, however, some internal resistance is always present.

Can the internal resistance be measured to judge whether the battery is good or bad? The answer is usually yes. The same battery will gradually wear out during use, the capacity becomes smaller and smaller, and the internal resistance becomes larger and larger.

When making battery measurements, it is good to know what are the the right internal resistance values to expect.

The typical internal resistance for new high-capacity NiMH rechargeable AA batteries is between 30mΩ and 100mΩ, and for an alkaline battery it is usually between 200mΩ and 300mΩ (but as high as 700mΩ, depending on its charge status). Faulty rechargeable batteries have a much higher internal resistance.

The internal resistance of the new 18650 lithium battery is generally below 50 milliohms, the better is about 20 milliohms, the general is about 30 milliohms. Here is a table for 18650 from https://www.xtar.cc/news/10-things-to-know-about-lithiuim-ion-battery-internal-resistance-224.html with somewhat different numbers:

What is the impedance of a 12V battery? The battery internal resistance values varies depending on the battery size. Lead-acid batteries typically have a low impedance, therefore the ability to deliver high currents. Typical impedance for a battery in the standby industry is 12V 80Ah VRLA battery that has typically around 0.003 Ω (3.0mΩ). The short circuit current is typically specified on battery datasheets, e.g., 2,500A for 12V 80 Ah battery. Those values can be used to get idea of the internal resistance (12/2500 = 0.0048 ohms).

A brand new, fully charged 12V lead acid battery typically has an internal resistance around 10-20 milliohms or less. If IR is between 5 to 10 milliohm, it is in good condition. If IR is less than 5 milliohm, it is in very good condition. If IR is between 10 to 30 milliohm, still poor condition but may be usable or revivable. A battery with an internal resistance above 50-60 milliohms is likely nearing the end of its useful life. 12V batteries with IR over 100 milliohms, are likely sulfated, damaged, or otherwise in poor condition and should be replaced.

Typical impedance for a battery in the standby industry:
12V 80Ah VRLA battery = 0.003 Ω (3.0mΩ)
2V 800Ah VRLA battery = 0.0002 Ω (0.2mΩ)

Table with more values from https://xtester.cn/product/RC3563_battery_Internal_resistance_tester.html

When measuring large-capacity batteries (the internal resistance is very small), you must pay attention to the position of the clip during the measurement. The internal resistance of the battery electrode or connecting wire is often greater than the internal resistance of the battery itself. Pay attention to the position of the clip and make good contact. To get an idea of the size of impedance, let’s compare the typical battery impedances to the resistance of the wire in a standard IEC power lead. The wire length equivalents of the impedances mentioned are 330mm (13.0 inches) and 22mm (0.87inches).

Product links:
https://xtester.cn/product/RC3563_battery_Internal_resistance_tester.html
https://www.amazon.com/LeTkingok-Precision-Handheld-Internal-Resistance/dp/B09HBYBWT8
https://www.aliexpress.com/item/32975204607.html
https://www.aliexpress.com/item/1005005930826266.html
https://www.aliexpress.com/item/1005005574356839.html
https://www.aliexpress.com/item/1005005538739198.html
https://www.aliexpress.com/item/1005005461280358.html
https://hklrf.com/RC3563-Battery-Internal-Resistance-Tester-100V-3Digit-Lead-Acid-Lithium-Battery-Tester-True-4Wire-Auto-Battery-Detector_1885.html

The tester has an USB interface to computer (looks like USB serial port with default baud rate 115200). Here are links to software to get measurement results to computer:
https://github.com/ludwich66/RC3563
https://secondlifestorage.com/index.php?threads/rc3563-ir-tester.8380/page-2#post-79687

The RC3563 is not the only battery resistance tester in the market. Another quite similar is YR1035+/YR1030+ Lithium Battery Internal Resistance Test Instrument that was reviewed in another site.

Korean Multifunction Counter Teardown
https://hackaday.com/2024/07/07/korean-multifunction-counter-teardown/

[Thomas Scherrer] likes to tear down old test equipment, and often, we remember the devices he opens up or — at least — we’ve heard of them. However, this time, he’s got a Hung Chang HC-F100 multifunction counter, which is a vintage 1986 instrument that can reach 100 MHz.
Inside, the product is clearly a child of its time period. There’s a transformer for the linear supply, through-hole components, and an Intersil frequency counter on a chip. Everything is easy to get to and large enough to see.
The oscillator inside has a temperature regulator so that once warmed up, it should be more or less stable.

Hung Chang HC-F100 multifunction counter 10Hz to 100MHz test teardown

this one uses one of the all in one frequency counter chips
prescaler and a very impressive temperature regulated crystal osc.

Also Radiomuseum has a page dedicated to Multifunction Counter HC-F100

https://www.radiomuseum.org/r/hungchang_multifunction_counter_hc_f100.html

The LED’s could be tested optionally with following currents: ca. 1 mA, 2,5 mA, 5 mA, 10 mA, 20 mA and 50 mA. I have tape over the 50 mA pins for safety (not to fry small LEDs accidentally with over current for them).

The test contacts are designed to accept brand-new LED’s as well as soldered out LED’s with residual soldering tin at the connecting pins. The connectors work acceptably for this application, but they do not always make the most reliable connection to LEDs.

In order to facilitate selection of LED’s of equal brightness, there have been placed two test sockets with the same currents (10mA) side by side. So you can quickly get comparable brightness LEDs before soldering them in your projects.

Let’s take a look at what is inside the box.

As you can see there are there are only connectors, resistors and battery in it. The 9 V/DC battery provides power and the resistors limit the current to the LEDs. Here is a closer look at the circuit board.

With 9V battery a resistor makes a decent current source only for LEDs with forward biases in a narrow range. The actual current will vary by about 10% for FB in the range of 1.6-2.2 V for most LEDs. The voltage drop over blue and white LED may be in range 3 to 3.5 volts, which causes the current through LED to be 20-25% lower than the shown current. The reason for that is that with traditional LEDs the voltage drop on current limiter resistors is around 6.8-7.4V. With blue/white the voltage drop will be only around 5.5-6V. The current through resistor is directly proportional to the voltage over it.

Here is a teardown of another cheap LED tester:
https://www.epanorama.net/newepa/2018/05/01/cheap-ebay-led-tester-fixed/

Electromagnetic field detector PEM A1 features:
For measuring electromagnetic fields from devices such as televisions, computers, microwave ovens, refrigerators, vacuum cleaners
Easy assessment with a 4-step LED scale (low or high radiation)
Batteries included
Measurement levels: 1.5/2.5/10/20+ mG
LED display: 4 levels (green / yellow / orange / red)

The meter is simple to use. You turn it on by pressing the red button in front panel and keep it pressed down as long as you want the device to be powered. When the meter powers up, it first turns on all LEDs, and then goes to measurement mode (all LEDs except green power LED are off when you are away from EMF sources). It is pretty simple meter and gave quite similar readings as some other meters. It feels OK, but has somewhat cheap plastic feeling in it (the price on sale was very cheap few euros). The meter seems to be mainly designed to measure mains frequency magnetic fields, but seems to also react to higher frequencies also (toothbrush charger and QI charger for smart phone for example).

Review videos:

Parkside Electromagnetic Field Detector PEM A1 REVIEW

Another video on the same topic with some errors on the measured units – This device measures EMF in milligauss and not in milligrams like said in this video Parkside Electromagnetic Field Detector PEM A1 REVIEW

Let’s take a look at what is inside it:

There seems to be a circuit board coil for magnetic field pickup. The signal from the coil seems to be amplified with few transistors (or FETs) before it is fed to main IC that drives the LEDs.

The IC in the circuit bard had following markings in it:
324
ST MZA4125

Technical specifications page from manual:

This protector protects against voltages above 320V AC (Uc) and is designed for circuits that a protected with 32A fuse (or fuse with a smller current rating). In addition there is another protection that rated Up %lt; 1.5 kV.

I removed the protector from holder and started to pry it open. The case shows the block diagram of the protector and how it should be connected to mains power. There seems to be a VDR with an over temperature protector between live and neutral. In addition there is a gas discharge protector from neutral to ground.

Here is the big gas discharge tube that is wired between neutral and protective earth. It seems to have an over temperature protector that has already tripped. The over temperature seems to be made of a spring contact that was soldered to the VDR output wire with some kind of solder (I suspect special low temperature melting solder).
Also the soldering quality on the bottom looks a a bit suspicious.

Here is some testing of the gas discharge tube with my withstand voltage tester. The first meaasurement shows the highest voltage the gas discharge tube can withstand before it triggers and the second picture shows the voltage when the tube has triggered (0.2 mA teat current flows through it).

On the other side there is a huge voltage dependent resistor (VDR) that is protected with overheating protector. The over heating protector seems to be similar spring contact and (low temperature) solder construction.

Here is the test of the voltage over VDR when it starts to conduct (at 0.2 mA test current, goes up slightly somewhat higher with higher test current).

Many mains power timers use mechanism that has mains powered syncronous motor, but this is different. This one has a electronic clock timer in it. There seems to be one clock IC with a crystal (around 4.19 MHz). The clock IC drives the stepper motor mechanism that moves the mechanical clock that controls the mains switch contacts.

The clock is powered from mains power using transformer-less power supply. That power supply consists of a capacitor, power resistor and bridge rectifier. The output from bridge rectifier goes to a resistor, which charges the rechargeable battery, main capacitor and the clock chip. I could not see any zener diodes in this circuit, and I suspect that the rechargeable battery is used here also as the component that regulates circuit voltage (NiCad battery might act the same as a Zener diode). The battery has leaked which could be a reason why this does not work properly.

The clock electronics is based on Eurosil 1115A that is an 8-pin clock chip which drives a stepper motor. It is equivalent to Intersil’s ICM1115A that has datasheet at https://www.datasheetcatalog.com/datasheets_pdf/I/C/M/1/ICM1115.shtml

Page 132 of the following document lists several Eurosil TIMEPIECE-WATCH/CLOCK ICs as cross references for Samsung parts: http://bitsavers.informatik.uni-stuttgart.de/components/samsung/1988_Samsung_Semiconductor_Product_Guide.pdf

Sources:
https://www.eevblog.com/forum/repair/recognize-this-ic/
https://www.badcaps.net/forum/showthread.php?t=8772&page=2

Any repair tips or recommendations for a good replacement (I want one with light and sound measurement built in).

The Acer Nitro 5 is a budget gaming laptop. This model was just around 4 years old. This computer was hit with two problems: the computer does not turn on and the screen hinge was broken.

Open the laptop by removing the bottom of the computer. It had many small screws that I had to remove.

For computer does not turn on problem I found the following links:

https://community.acer.com/en/discussion/567979/how-to-fix-acer-nitro-5-nitro-5-an515-51-black-screen-that-wont-start-up

https://www.ifixit.com/Answers/View/754153/Nitro+5+refuses+to+turn+off+on+after+charge.

FREE BROKEN Laptop – But Can I Fix It? Acer Nitro 5 No Power (Gifted From A Subscriber)
https://m.youtube.com/watch?v=C4S6QL4keOQ

ACER Nitro 5 gaming laptop repair – Not coming ON, not charging board repair
https://m.youtube.com/watch?v=uohBIm59MY0

https://onlinecloudsecurity.com/acer-nitro-5-will-not-turn-on/

https://www.geekbuffalo.com/computer/acer/how-to-fix-the-acer-nitro-5-laptop-that-wont-turn-on/

I did not manage the laptop to boot with any easy tips. A repair shop looked at it, but did not get it to boot as well. The problem was not in battery (did not start without battery). The end result was that that motherboard was broken (which means too expensive to be worth to fix).

Because computer could not be made to work, it was not worth to try this hinge repair tip (which I would have done if the computer would boot):

How to Fix BROKEN SCREEN HINGE on Acer Nitro 5 Easily!
https://m.youtube.com/watch?v=BYDJRoJMZ1s