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

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0
votes
2answers
14 views

Can a 9v battery be substituted with an array of LiIon 3.7v?

I use some audio devices (mixers and effect boxes) that literally drains out my 9v cells (specially the rechargeable). I'm thinking on doing arrays of LiIon batteries (rated at 3.7v-4000mAh each), ...
0
votes
2answers
71 views

How to calculate power supply for 100x loads @ 3V 700mA

I'm currently designing a setup using 100x loads that requires a 3V 700mA supply ea. The loads are connected in parallel with the main power supply. I'm a bit doubting about my power supply dimension ...
0
votes
2answers
48 views

When replacing a PS, how do I know I'm safe if device doesn't list current? [duplicate]

I recently acquired a Lantronix UDS1100 telnet-> serial converter. It came without a wall wart / power supply. I have an extra power supply from an old modem that I think might work, but I want to be ...
0
votes
1answer
13 views

Sharing the Seeeduino LiPo with a motor controller

I'd like to use a Seeeduino to control a small DC motor to wind/unwind a thin cable which will be lifting a small door. Ideally, I'd like to use the same LiPo that's being used to power the ...
0
votes
1answer
24 views

Sharing negative terminal (“ground”) between 2 LiPo batteries and UBECs / paralleling 2S LiPo packs

One of my projects require a hefty amount of amperage - and as such I want to use 2 LiPo 2S batteries, in parallel. In addition, I am regulating the voltage using multiple DC-DC step down converters ...
0
votes
1answer
55 views

Identifying DC electrical power connector

I have here a PowerFilm 10 Watt F15-600 Solar Panel, and attached to the panel is this connector: The male end attached to the panel has a little green rubber gasket on it and the female end ...
4
votes
5answers
207 views

High Voltage differential Measurement

Suppose I want to measure individual cell voltage of a 12-serial-cell battery pack, what would be my most economical options? Single cell voltage is 3V-4.2V but the stack can be between 2-12 cells ...
2
votes
2answers
55 views

How to power a Arduino Yun with a 6V battery?

I would like to power my Arduino Yun board with the following battery: Arduino Yun has a VIN pin that represents the input voltage to the Arduino board. The official documentation says: Unlike ...
1
vote
2answers
78 views

Designing effective usage time from 12v car battery

Need a little power design help: I have a project I'm working on where I have measured that I will use approximately 14.4Ah over 24 hours. This is quite the load for a small timelapse setup where I ...
0
votes
1answer
59 views

In any circuit we can always control the input power? [closed]

In any circuit, we can always control in voltage and current? We can stabilize them any value we need, given a good power source? Also, we can increase voltage in a circuit without changing current ...
1
vote
6answers
154 views

Why is pin protection needed?

I have read this article about protecting input pins. One thing is still unclear to me — why is the protection needed at all with such a high resistance on the input pin inside of the ...
0
votes
1answer
46 views

Debugging power on issue [closed]

First off I don't know if this is the correct fora, for this kind of question. My personal Acer Aspire 5745G has an issue, namely that it usually has issues powering on. The issue is that when the ...
-1
votes
2answers
62 views

Fast thermal ramp up/ power efficiency [closed]

I want to build a controlled temperature well in an alumminum block, and right now I am in doub as to what heating method choose. I am mostly torn between a high power resistor such as this or ...
0
votes
1answer
57 views

Reduce discrete linear voltage regulator dropout

I am investigating the following circuit taken from here which works fine in simulation. However, while Vout rising linearly with Vin it shows a ~800mV dropout, which I don't quite understand. ...
0
votes
0answers
39 views

Poweline Communication? [closed]

I want to implement power-line communication over the area of up to 100 sq.meters. to establish intercommunication between up to 100 devices with the rate of several kilobytes. I studied different ...
8
votes
3answers
870 views

What simple IC can I use to extract 500ma from a computer USB port?

I have very small and simple electronic projects that I power up using the USB power connectors plus a resistor. For one project I require to use more than 100ma, however the USB port requires an ...
0
votes
3answers
85 views

Shunt Resistor on output of Voltage Regulator? [closed]

I was looking through a popular circuit on Sparkfun and trying to lower the power consumption of the device. I found that the outputs of their regulators are shunted to ground with a 300-ohm resistor. ...
0
votes
2answers
59 views

NCP51460 alternatives

The NCP51460 20mA Precision Voltage Reference with it's wide input voltage range of up to 28V seems interesting for our current project, more-so considering the very competitive current price at ...
0
votes
1answer
65 views

How much will be maximum power capacity of a transformer with supper conducting wire

If I wind a specific transformer with superconducting wire and take away temperature from the core by means of some way, how much power can I take from transformer? I should mention max power capacity ...
0
votes
0answers
44 views

Modelling Hot-Plug event

In a related question I described unexpected (smulation) behaviour of a P-Ch. MOSFET high-side load switch when input voltage rises very steeply. Now, admittedly a step input can't quite be a good ...
-2
votes
2answers
147 views

Is it possible to carry over 20MW? [duplicate]

Is it possible for a series of conductors carry massive currents(100 kA) at voltages over 100V? Assuming there is massive cooling. How can power plants carry MegaWatts of power?
0
votes
0answers
27 views

Three Phase Power. Phase Currents to Power and KVA calculations

I'm trying to learn a little bit more about three phase current, power and KVA. We currently have some hi-tech UPS power systems at work and I'm trying to ensure that they are adequately provisioned ...
1
vote
1answer
95 views

Capacitor placement / count

I'm building a circuit that has a number of servos on it. To eliminate servo chatter, I've seen recommendations to put in a 250uF cap (for the size servos I'm using). That much I can follow. The ...
2
votes
1answer
44 views

How do variable current limiters work in power supplies?

Bench top power supplies often enable you not only the set the voltage, but the maximum current. How do these bench supplies provide this variable current?
2
votes
1answer
75 views

Two power sources, auto-switch?

Quick question (hopefully!). I'm new to electronics, but getting quite interested. Coming from a programming background, it's always interested me... Anyway. I have a circuit with two DC Power ...
-1
votes
0answers
49 views

Stable current?

A large conductor that carries massive amounts of current at extremely low resistance(micro-ohms), now back EMF is induced that is really large. Let assume V = 0.2 volts and -V = 100 volts, and I ...
-3
votes
1answer
27 views

Question about ideal transformer

Let's say that an ideal transformer has a rating of 500/125 V, 10 kVA. The source voltage applied to the primary winding is 525 V (rms). The load that is connected to the secondary winding consumes ...
0
votes
4answers
242 views

Strange amplitude fluctuation in video signal

I am reading a video signal from a CCD array. For some reason I get this extreme vertical jitter. I use decoupling and bypass caps everywhere possible. But it does not seem to be the noise issue. Any ...
0
votes
1answer
61 views

How does the principle of conservation of energy for a phase-shifter transformer apply?

Since the phase shifter transformer is used for regulating the real power in the transmission line by means of changing the angle it leads to the fact that the real power at the secondary side ...
4
votes
2answers
128 views

How should I design a power bus for a wearable project?

I am thinking about building a(nother) wearable LED jacket project. The basis will be 60 LED/m WS2812B strips, around 2048 pixels, for a peak possible current draw of just under 125A. In reality I ...
8
votes
3answers
1k views

Why too many capacitors in parallel for Vdd supply net? Can't we just add all to replace with one big capacitor?

I have given the image of Basys-2 board's power regulator IC and filters connected to it in schematic. This is just an example but this is pretty much a similar filtering design for most of the supply ...
0
votes
1answer
58 views

How to use MOSFET thermal data for simulating in software

I have a MOSFET (irfb7434pbf) acting as load switch in a circuit. The usual operation is well within the SOA region, but, on situations where the load would short circuit, the MOSFET is set to limit ...
0
votes
1answer
38 views

Low Current Battery Montior Detail Question

I'm trying to design a circuit that will be running from a battery. I'm currently working on the part that detects the voltage and came across this question (and answers) here: It made pretty good ...
1
vote
1answer
58 views

Power Supply for LED Project

I am working on a project where I have to power a 5 meter long LED strip (https://www.sparkfun.com/products/12022) and 54 3.4V 20mA LEDs and control them all from an Arduino. My current idea was to ...
0
votes
2answers
70 views

5V wallwart to 4 USBs and 3Pin fans

I am working on a small Raspberry Pi cluster that I am going to use for web hosting, home automation, cloud storage, VPN, and so on. I plan on using the 3D printer and laser cutter/engraver at my high ...
9
votes
3answers
205 views

What is the correct spelling/capitalization of watt hour?

In some documentation I have commented that a field contains "the forward active power, in Wh". Which way should it be written (when I don't want to use the abbreviation)? the forward active power, ...
10
votes
7answers
1k views

Is there a constant power supply?

A voltage source is a device that produces constant voltage, but allows amperage and power to vary, in accordance with the laws of electricity. An current source is a device that produces constant ...
0
votes
1answer
106 views

How to short a push button switch to be always on

I have a little bluetooth FM transmitter that uses a single button that you press and hold to turn the device on, press and hold to turn the device off, and press once to change the FM station it ...
1
vote
0answers
46 views

Antenna array weights and Power input

A big request for clearing this simple doubt. For an application, I am using antenna arrays(say dipoles and array length is 11 elements). Now, this antenna array will have the beamforming vectors ...
0
votes
3answers
108 views

Unplugging home TV saves power? [closed]

I've tried to find recent articles about how to save electricity at home. I remember the most basic instruction was to unplug everything that was not being used at that moment. My problem is that I ...
0
votes
1answer
124 views

How can I limit the current in a 12v car battery to be safe for my 25a motor driver?

I have a 25amp Sabertooth Motor controller that can be powered by my 12v car battery. I have big 24v wheelchair motors attached to the motor controller. I do not know how much current that the motors ...
0
votes
2answers
127 views

Is it wise to use an Arduino to power a crystal oscillator?

I'm building a small VGM audio player. I currently have a SN76489 (here) that is clocked from a 3.579 crystal oscillator. When ...
0
votes
1answer
78 views

Li-ion battery choose question

I am new to this forum and I hope you can help me with this. I want to build a small circuit that will have: an ATXMEGA ucontroler that uses all of its 5 USART and one bluetooth module. This circuit ...
0
votes
3answers
118 views

Regulated +5V drops when relays are switched on

A regulated power supply RAC02-055C/277 provides 5V to an Arduino driving 2 relays. The power supply is rated to provide 2W of power. Connecting a multimeter between one of the leads of the power ...
1
vote
3answers
64 views

What do the abbreviations “SPF” and “SPH” mean with respect to fuses? (Single line drawing for 480 V system.)

There are two lines connected between the transformer low voltage side and the 480 V bus, one with a fuse labeled "SPF" that connects to a GE power quality meter, another with a fuse labeled "SPH" ...
0
votes
1answer
59 views

Power opamp 'floating' output

So I had to design an amplifier with a 'floating' output. (I don't know if floating is the right word, it's the direct translation from dutch.) See the picture below ( I drew it whilst sitting in the ...
2
votes
1answer
43 views

load switch capacitance constraint

Considering using a Load Switch like DigiKey FDC6330LDKR-ND for powering on and off a device at the far end of a cable. The voltage and current requirements are well within spec however load ...
3
votes
1answer
87 views

Power up sequence

I am designing a hardware a specific power up sequence is needed. The Vdd_33 should come 10uSec after vdd_18. I have LDOs for these supplies, one option is to control the power distribution with ...
0
votes
2answers
59 views

Basic question regarding power consumption of different devices

I have current values for devices measured at different DC voltages. 4.2mA at 2.4V 68.8uA at 3.0V 44mA at 2.0V 65mA at 3.4V If I were to power them at a voltage of 3.6V and would like to ...
0
votes
0answers
72 views

Powering AVR project

I am building new project, which I will power up the water tank heater from my smartphone. I have few safety though I want to ask here to get your opinion. I am going to use AVR to run a relay, that ...