Test and Measurement

Internal resistance is the opposition to current flow within a battery, caused by its materials, chemical processes, and structure. It leads to voltage drops and heat generation under load, and typically increases with battery aging, temperature changes, and usage, affecting overall performance and efficiency.If you are discharging batteries with Otii Arc and Ace Pro and Otii Battery Toolbox your battery discharge profiles for pulsed loads will include internal resistance information and can therefore be used to emulate battery behaviour.

When measuring currents and voltage with thin, long cables the resistance in the cables and connectors might cause errors in the voltage measurement. In a 2-wire setup, current and voltage share the same path and resistance can affect the accuracy. A 4-wire setup uses separate wires between power and voltage sensing, thus avoiding the added error that the cables and connectors introduce. 4-wire measurements can be used in any set-up with Otii Arc 256-4687 and Ace Pro 257-3555.

Low-power measurements aren't about how small a value you can detect — they’re about how accurately you can measure those small values. Accuracy is specified as ±(gain error + offset error), or ±(X% + Y), where X is the percentage error and Y is the offset error. This means your measurement includes both a fixed offset error of Y and a scaling error of X percent. Example: the current measurement accuracy for the main channel of the Otii Ace 257-3555 when measuring low currents is ±(0.05% + 25nA). So if you measure 1 µA, the expected error would be a maximum of 0.0255 µA.

In-line (Ampere Mode) power measurement the measurement device is connected in series with device under test, measuring the current flow through the system. Named after "ampere meter" since it primarily focuses on current measurement. Most instruments provide either full power mode measurements or only ampere mode measurements. Otii Ace Pro 257-3555 provides both options. Furthermore, to measure additional voltage, power, and energy, the ampere mode setup can be extended with a 4-wire connection using SENSE pins in the expansion ports of the Ace.

  Wide dynamic range refers to a system’s ability 257-3555 to accurately measure or process signals spanning a large range of values, from very small to very large, without compromising the precision. In the context of low-power measurements for embedded electronics, this means capturing everything from deep sleep currents in the picoamp range (pA) to high current peaks in the ampere range (A). With a resolution of 400 pA and the ability to measure across 10 orders of magnitude, you can seamlessly profile sleep, standby, and active states without losing critical details.

How can I control the brightness of the sensor? Can anyone recommend an affordable, entry-level hardware solution that would accomplish this? (Other programming languages, Raspberry Pis, or microcontrollers are not considered.) A friend sent me this code: #include <stdio.h> #include "CH341.h" static int open_device(HANDLE *out) { *out = CH341OpenDeviceEx(0); if (*out == NULL || *out == INVALID_HANDLE_VALUE) { return -1; } return 0; } static void close_device(HANDLE h) { CH341CloseDevice(h); } static int configure_io(HANDLE h) { if (CH341ResetDevice(0) != 0) return -1; if (CH341SetOutput(0, 0xffffffff, 0x00000000, 0x00000000) != 0) return -1; if (CH341SetOutput(0, 0b11111, 0xffffffff, 0xffffffff) != 0) return -1; return 0; } int main(void) { HANDLE hdlCh341; if (open_device(&hdlCh341) != 0) { fprintf(stderr, "Failed to open CH341 device\n"); return 1; } printf("%lu\n", (unsigned long)hdlCh341); printf("%lu\n", CH341GetVersion()); if (configure_io(hdlCh341) != 0) { fprintf(stderr, "Failed to configure CH341 I/O\n"); close_device(hdlCh341); return 1; } close_device(hdlCh341); return 0; }

An isolated power supply is a power source where the input and output are electrically separated using transformers or optocouplers. Isolated power supplies add an extra layer of safety, reduce noise and enable parallel or series connection with another power supply to increase output power. Otii Ace Pro 257-3555 is an isolated power supply.

Burden voltage is the voltage drop in the current measurement instrument with a shunt resistor in series with the device under test (DUT) while measuring the current. Burden voltage alters the measurement, leading to inaccuracies, especially in low-voltage and low-power applications.  Otii Arc Pro 256-4687 and Otii Ace Pro 257-3555 actively regulate voltage, eliminating burden voltage for reliable and precise low-power measurement. 

A fuse carrier is an integral part of an electrical circuit that securely holds and connects a fuse so that it operates safely and performs the designated function. It is a protective housing that provides a point of access to the fuse and allows the fuse to be installed, replaced, and inspected without handling live components. When the fuse carrier is put in the circuit, it provides for the fuse to be aligned properly and provides a good electrical contact to the circuit terminals. If an overcurrent event takes place, or in the case of a short circuit, and the fuse in the fuse carrier blows, the electrical connection is broken, and the load or equipment parts that could be damaged or cause a fire are protected. The fact that it was the fuse carrier that protected the event from happening, and that allowed it to happen safely while keeping the user isolated from the high voltage parts. Many fuse carriers also have additional safety features that provide enhanced protection and provide peace of mind, such as terminals being finger safe and lockable covers, or being able to see visually that a fuse has blown or not. Fuse carriers are commonly found in industrial electrical panels, residential (consumer unit), and control systems. Referring to a fuse carrier allows for maintainer convenience and enhances the safety and reliability of the user's electrical system. Fuse carriers allow technicians to reduce the time to replace a fuse and reduce the risk of loss or injury, allowing them to do so safely, reduce downtime, and maximize safety with conformity.

I just started using this software (Ultiboard). I want to use it to design PCB boards. How can I change the size of this software? Or is there any other software you recommend that you can tell me?

I wonder if someone has a very simple special LED flasher ( using discrete components) with a uP GPIO input to stop the flashing and constantly turn on the LED. What I want to do is flash the LED, telling the user that the power is on and waiting for the computer to boot up. Then, when the computer has booted up, the LED changes from flashing to a constant on. The uP signal is a 3.3VDC and goes high when it has booted up. I am hoping the flasher supply voltage is 3V, and I want to use SMD MOSFET compounds if possible. The flash rate should be somewhere around 2 or 3 flashes per second. I found on the line LED flashing circuits, but the transistors in those designs are obsolete.  Thanks for sharing.     

Why is it different from the pins in the schematic diagram? For example, RX & TX are its pins 35 & 36, but in the datasheet & reality, they are 28 & 29. Please help to correct this error.

How much embedded RAM is integrated into the EP4CE55F23I7N?

How do you approach debugging intermittent failures that might be related to a specific capacitor, like a Murata GRM series MLCC, experiencing temperature-dependent issues?

I am working on a Raspberry PI Python app I discovered something strange. The code does not detect a push button with my DVM connected to a test point, (the push button signal). Removing the DVM, the code works correctly.  Has anyone ran into this?