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Questions tagged [power]

Where power is a primary concern for the design under discussion. Use the "low-power" tag when that applies.

3
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0answers
62 views

Power use question for a trail camera

I am trying to calculate how long that a trail camera can be deployed before the batteries run out. The trail camera in question is a Reconyx HyperFire 2. Here is a useful review of the trail camera ...
3
votes
0answers
220 views

What determines the actual power consumption of writing to a microSD card?

I'm currently working a project that will feature writing data to a microSD card. Because my project will be battery powered with a 125mA power regulator, I'm concerned that my write operations will ...
3
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0answers
2k views

How to make your own EL Wire (electroluminescent wire) inverter

I would like to make an EL wire (electroluminescent wire) inverter because I can't seem to find a commercial inverter that can drive the right length of wire from the batteries I would like to use: ...
2
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0answers
28 views

Deriving the equations of power flow between buses

Can somebody please explain for me how to mathematically derive the equations of power flow between two buses? The equations I am trying to derive: Equations of power flow between buses I read the ...
2
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0answers
40 views

USB Type-C DRP Integrated Switch/Interface Chip

I would like to experiment with a power bank design with a single usb type-c port. The port should have dual role, source current for charging other devices as well as sink current for charging itself....
2
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0answers
26 views

Context of Li-Ion MnO2 “Cell Configuration” Specification

My application supports variable pack configurations: 4S4P, 4S6P and 4S8P. Each one obviously uses a different BMS profile, and other minor changes such as charge/discharge MOSFET and fuse selections....
2
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0answers
136 views

Overshoot/undershoot issues in load current wave form of a MOSFET

We have designed hardware circuit which validates voltage regulator maximum output current. So we designed op-amp circuitry to control gate drive of the Power MOSFET and it will work in active region ...
2
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0answers
39 views

Way of powering Arduino+GSM Modem+Cam off 5V powerbank

I'm trying to build a circuit, that would turn the Arduino on by a PIR sensor, take the picture by ArduCam, then transfer it onto a webserver. I got the SW site covered by now, so that is not a big ...
2
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0answers
60 views

Y/Y/Δ or Δ/Y/Δ transformer for a series connected 12-pulse rectifier?

I'm aware that 30° shift is needed in order to obtain a 12-pulse rectification, however, I'm a bit confused about the configuration of these transformer. In most HVDC systems that appear in Alstom - ...
2
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0answers
130 views

Why does my SEPIC converter output more power at higher temperatures? What are the implications of this behavior?

I have a Pololu S18V20ALV SEPIC voltage regulator board that is wired to a high-amperage 5V USB power source on the input and a DC brushless fan on the output. The output is set to about 5.5V. ...
2
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0answers
117 views

Q: What is the power of this signal

Determinate the power of the discrete signal: $$x[n] = u[n] + (-1)^n + (\frac{-1}3) ^n * u[n]$$ where: $$u[n] = \begin{cases} \ 1, & n \ge 0 \\[2ex] 0, & n \lt 0 \end{cases}$$ The answer ...
2
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0answers
81 views

Audio: Camera activated external microphone

I want to build a relay circuit that turns on an external microphone (powered by an internal 9V battery) when a connected camera is turned on (a camera offering only 1V plugin power through a 3.5 mm ...
2
votes
0answers
462 views

What's necessary to properly decouple/filter a PWM-controlled fan from an Arduino?

I've got a small problem I could use some help with. I am using an Arduino to control a cooling system I am building for a DSLR. Primary goals are to use PWM and some pots to control TEC power, as ...
2
votes
0answers
97 views

Getting more than 0.5W from USB OTG

Has anyone actually measured the maximum amount of power that can be drawn from a smartphone's (say Samsung S4) USB OTG in host mode? I've read people suggest 100mA but can't find if anyone has ...
2
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0answers
371 views

Strange stepper motor behavior- moves too far

I have 3 CD drive stepper motors on a 9V 2A power supply, and they are being driven with EasyDrivers. I am using an Arduino with grbl to control the drivers. The current for the motors is at the ...
1
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0answers
20 views

24-60V Precharge schematic critique

I'm looking to design a soft-start precharge circuit for starting up circuits with substantial input capacitance (~1.5J @ 24V). The main requirements are: 24-60V compatible Constant current pre-...
1
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0answers
26 views

Changing between usb power and battery power using P-Channel MOSFETs and a CMOS Invertor

I am trying to switch between USB power and a single cell lipo using two mosfets. Would the circuit below be ideal or is there a more efficient/reliable way to do this? When the USB is connected the ...
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0answers
19 views

Is it possible to predict the operating state of a power system (using MATLAB) if I have calculated the voltages at all nodes by state estimation?

If I have calculated all the node voltages by state estimation, is it possible to predict which operating state my system is at? By operating state, I mean any of the following: ...
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0answers
70 views

Repurposing or obtaining a cheap audio signal amplifier for school physics lab

I teach highschool physics, and want to connect my smartphone (LG V20) to a Chladni plate (vibrating plate for studying interference patterns in sound in solids). I have successfully done this by ...
1
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0answers
24 views

What is the best way to isolate power hold-up circuit?

I an currently designing a hold up circuit for a computer and I need to keep this load isolated from other circuits that don't need to worry about a brief loss of power. The research I've done has ...
1
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0answers
46 views

Raspberry Pi wake-up and battery power circuit

I am working on a Raspberry Pi (3B plus) project that - at times -needs to operate on battery power, and on external power whenever available. The RPI needs to operate only when a dedicated sensor ...
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0answers
35 views

How can we make a load that has configurable power factor for 230V AC?

We are hoping to create a lab for students at our university that requires them to measure the power factor and correct for it. We are working with 230V AC and have a maximum power of 300W. We were ...
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0answers
59 views

Generate energy from waves that move my ship?

I'm currently building a small solar powered robot boat. I expect it to work fine (because why not.. :-) ), but I'm already looking for other ways than only solar panels to generate electrical power. ...
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0answers
30 views

Battery Powered System and Input Capacitance

I have a battery powered system in which the battery is connected to a buck/boost converter to derive 3.3V from two or three AA batteries. The regulator I'm using is a TI TPS63050, and it has a power ...
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0answers
62 views

What are these programming terminals for a 2 kW power supply?

Does anyone recognize the programming terminals on the real panel of this power supply? I would like to get the 50 amps out. It is an ATE1 made by Redfern radio, it is an old army surplus. Going in ...
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0answers
26 views

Reactive Power at Slack Bus

When computing the power flow solution, we find the (1) voltage angles at (a) load nodes and (b) non-slack generator nodes, and (2) voltage magnitudes at the (a) load nodes. We can then compute the ...
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0answers
46 views

Rise time and fall time issue in the power MOSFET

In our automated design due to MOSFET obsolete we have changed new MOSFET which gives us rise and fall time issue at the frequency applied from 10Khz to 500Khz. when we use the power MOSFET as Load ...
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0answers
78 views

Producing clean power with multiple switch mode power supplies

Thanks, I am new to using this site, I apologize for my vague post earlier. Here is a schematic I been working on. The project requirements are 5VDC, and 20VDC. The 5VDC is to power the ...
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0answers
43 views

Voltage drop on power bench supply for channel being off

If I measure voltage drop between terminals of my bench power supply (spec) I get -15 mV when channel output is turned off. Why it is not reading 0? I believe it's due to internal impedance of the ...
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0answers
24 views

Split Power Plane when using Load Switches?

To do power saving for a battery operated product, I am using couple of load switches to shut down peripheral power when not using that. PCB stackup - Signal(component), Gnd, Power, Signal -- 4 ...
1
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0answers
50 views

What factors should I consider when choosing a high amperage power supply?

I've searched around, but I haven't found an answer to this particular question yet. I'm building an elecromechanical project which requires somewhere around 60 Amps at 12 Volts. While this may not ...
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0answers
100 views

Designing a +10 V -10 V +7 V DC power supply for audio equipment

I've recently purchased a tape recorder (Tascam Midistudio 644) that was very cheap because the previous owner had lost the power supply. The PS-M1 power supply that originally came with this unit is ...
1
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0answers
61 views

Inrush current limiter circuit for filament bulb - comparison

Context: A 12V power supply is switching on externally connected 12V filament bulbs. The power supply's load switch implements an electronic resetable fuse (13A/τ=15ms) in case of an external short. ...
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0answers
68 views

MPU6050 hangs on ESP32 when operated using a battery on custom board

We are facing a very peculiar problem. We are designing a board based on ESP32 with various peripherals like motor drivers, sensors etc. We are using GPIO 4,5 on the ESP32 as I2C lines and have hooked ...
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0answers
23 views

Hook up an automatic transfer switch with two phases only

We have a house in Haiti connected to the shore line. The shore line isn't always working so we bought a generator. I wanted to ground one of the two phases to create one neutral, one phase and a ...
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0answers
106 views

Power consumption measurement on the bench

I've been using the Atmel Power Debugger to sort out power consumption issues on some µController based circuits... and have been pretty pleased. Unfortunately, it's limited to a maximum of 5.5 volts ...
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0answers
278 views

IGBT failure and protection

I have a 3-phase bridge rectifier (shown below). I am using an IGBT (STGE200NB60S) to limit the inrush current from the capacitors at start up. I also added the NTC thermisters to help with the inrush ...
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0answers
52 views

Is there a cost savings associated with 3 phase power at the same device power requirement (kW)?

I am a Mechanical Engineer looking into purchasing an annealing furnace and have seen that some operate on single phase power while some operate on 3 phase power. I've done some research and have seen ...
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0answers
53 views

Brick SMPS power supply issues

I'm working on a system comprised of two boards (power board, screen board) powered either via European outlet (220v 50Hz) or a LiPo battery. Power handover is achieved via an autoswitching MUX that ...
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0answers
316 views

Soldering sheet busbars to PCB concerns

Hello fellow engineers I have decided to solder busbars to a high current pcb , but i have 2 concerns : Does soldering a flat busbar (shown in left image) could cause thermal stress and deformation ...
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0answers
91 views

Are there commonly used equations for short-term overpower of wirewound resistors?

If I have a wirewound resistor rated for 250 W that might need to dissipate, say, 400 W for several seconds, is there a commonly used equation for finding its temperature rise or time to failure under ...
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0answers
103 views

aluminum anodizing power supply schmetic

It has been a long time since I played with the electrons. In my day filament transformers were common and power supply design included the number and type of tubes being used.LOL Anyway I need to ...
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0answers
104 views

Gate Driver Not Working as Expected. Why?

I am using the ADuM5230 gate driver to drive an N-channel MOSFET in a basic buck converter circuit that will convert a 12V DC input to a 5V DC output. The buck converter will operate at a 10kHz ...
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0answers
50 views

Daisy chaining power through mcu modules

I am really sorry if the following question is too obvious and basic, I am trying to understand how I can do this right. I have five 5V PIC custom modules that I am trying to power, using a daisy ...
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0answers
225 views

Which power factor is better in an industry -0.21 or -0.94 and why?

In the electrical panels , when i switched on-off the capacitor bank then power factor gets shifted from 0.89(lagging/during OFF condition) to -0.87(leading/during ON condition) , similarly on ...
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0answers
197 views

Magsafe to USB-C adapter

I would like to create an Magsafe 1 to USB C adapter to re-use my macbook magsafe charger on my usb-c macbook. I have these components below and already tried to connect both V+ and Ground with no ...
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0answers
77 views

Power sequencing with LDO without enable pin

What is the right way to provide a power sequence using LDO (or any other power source) without the enable pin? I'm using DAC7718 from Texas Instruments and it require a quit complex power sequencing:...
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0answers
62 views

Designing Battery Power System For Robotics

I'm building a mobile robotics project for a class and I'm trying to figure out how to (or even if its necessary) to design a nice battery power system for it. I sort of wanted to learn how to build a ...
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0answers
88 views

Am I right about measuring current, and power

I have a meter that can measure: current, active power, reactive power and complex power. simulate this circuit – Schematic created using CircuitLab So, when I measure the four things: current,...
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0answers
512 views

Potential difference between DC floating power supply and earth ground

I have a question about a simple DC floating power supply: it is as simple as possible, secondary coil -> bridge rectifier -> filter cap, as shown on the figure below. If I connect the input of the ...