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

learn more… | top users | synonyms

0
votes
0answers
11 views

Running 2 5V USB battery power packs, Can I use them in parallel

Can I run two 5v power packs in parallel to give me more mAh's (Time)? Or will one try and charge the other? Example I.E. connect both 5V lines together, both GND lines together to my device
0
votes
0answers
18 views

symmetrical components and power conservation?

My understanding of the method of symmetrical components is the following: An unbalanced three phase system (voltages, currents etc.) is split into three balanced sets; zero, positive and negative ...
-3
votes
0answers
51 views

Does a switched on power socket consume electricity? [on hold]

Let's say I have a TV and a power socket. The TV's switch is open and the socket's switch is closed. Will this outlet consume electricity?
0
votes
1answer
32 views

Protect Beaglebone Black from Power Outage

I am using a BBB (Rev C) as a web server, powered by a 5V power supply connected to the 5V jack. I read in several locations that disconnecting the power supply to turn off the board can damage the ...
0
votes
0answers
19 views

Powering a 5V device from one or more sources

I'm building a circuit and need to power a PICAXE IC from one of two possible sources - a USB 5V connection (which provides power for the Adafruit Powerboost 500 charger), or a Raspberry Pi, which ...
0
votes
2answers
43 views

USB power in Parallel, increasing the maximum current using a Y splitter idea[POWER ONLY]

When you connect batteries or power sources of the same voltage, in series, the voltage adds together. When in parallel the capacity of the two add together. Ive seen a few usb>sata cables in which ...
0
votes
2answers
50 views

What sized motor could spin ~2lbs?

I am working on a prop for a film -- I have to make a sign spin in a circle (simple attachment to a motor) and have variable speed. I know enough to wire the thing, but am having a hard time getting ...
0
votes
0answers
29 views

Ups or voltage stabalizer ? What isbest in this situation? [closed]

I damaged my macbook charger due to power surge or drop maybe not sure when switching to and off power from home generator To prevent it in future can i use a ups with the charger to prevent such a ...
-2
votes
0answers
23 views

Power flow on branches using matrix algebra

Having: S: The vector of power injections at each bus. V: The vector of bus voltages. Y: The circuit admittance matrix. A: The branch-bus connectivity matrix. ...
0
votes
2answers
24 views

PLC For MV Networks

Can power line communication work over both live LV (+-230V) and MV (11kV) conductors? Is there hardware available that makes this possible? Up to what voltage is power line communication possible?
0
votes
2answers
49 views

DC Supply Load Dummy based on NPNs

I am fixing an old regulated load dummy that I use in my workspace. It was a mess and I want to modify its regulator side. My question is: will the circuit showed in the image work properly? If you ...
2
votes
1answer
297 views

Whats the overrall power available from two PSUs in series?

Consider this circuit: PSU 1 is rated at 100w, PSU 2 is rated at 200w. How do I calculate how much power is available to the load, given the mis-matched power supplies?
-2
votes
0answers
14 views

Need to Calculate the inductance for the single-phase version to have 5% ripple current under both boost and buck modes, assuming 100 kHz switching. [closed]

I need to know more on buck and boost converters it would be more helpful. In addition if anyone of you can provide me the solution to the problem it would br helpful.
1
vote
1answer
27 views

KiCad: Power with hierarchical sheets

I just started trying to use KiCad (complete newbie), and I have a very basic question about using power inputs with hierarchical sheets. Let's say I want a single LED on a hierarchical sheet, while ...
0
votes
1answer
60 views

High voltage on home appliances surfaces [closed]

I noticed that some of the appliances in my kitchen can cause some sort of a small electric shock. At first, I though it is just an electrostatic discharge, but when I measured the voltage between the ...
0
votes
1answer
64 views

Power Switching with Microcontroller

I am in the process of designing a device for a uni project. As a requirement, we are required to have a very low power consumption whilst in standby mode. Our plan for this, was to have our 2 x +-5V ...
1
vote
1answer
57 views

Adding a remote switch and battery to a 9 volt dispenser

I have an insecticide dispenser in my shop. The unit is designed to spray a short burst of insecticide once every 8 minutes. I have found I don't need this frequent of a burst and my thought is to ...
0
votes
2answers
40 views

compare high power mosfet for high power load

I'v been searching mosfet for high power load project (DC 110V 100 Amp) and I found Fairchild FDL100N50F (TO-264) with maximum Power Dissipation 2500W. According to data sheet, the Max SOA DC ...
0
votes
1answer
45 views

3v wireless arduino and power consumption

I decided to create another post in order to get feedback for my ideas. I have created a network of wireless sensor nodes which connect to a central arduino with serial connection to a RPi. I ...
1
vote
2answers
160 views

Help me identify this mystery IC? [closed]

I had a bug (yes, a literal bug) decide it would be a good idea to crawl inside my printer and short itself across two pins on my printer's power supply board. I have pulled the board in the hopes of ...
0
votes
0answers
59 views

Power Consumption [closed]

I have a power supply circuit. It is a power supply unit with 32 AC output channels. And I do not know how to calculate power consuption. What I know is , I am givin 60 Volt DC, from power source ...
0
votes
2answers
69 views

RF Transmit Power in an ISM band

I was browsing through some OFCOM Frequency Allocation Tables for use on a small project I'm doing. I require the use of some unlicensed ISM bands in the UK, and found that the lowest unlicensed band ...
0
votes
2answers
33 views

Find which wires are what in a sjt power cable

I'm trying to figure out what wires are live, neutral and ground in my computer power cable. I'm getting some weird readings from the wires. ...
0
votes
1answer
91 views

Rapidly switching on and off a 12v power supply, bad idea?

I was just wondering if this would be a bad idea, the power supply is connected to the mains power and would only undergo this at a max of 10 minutes at a time. would this cause any damage to the ...
0
votes
2answers
49 views

RF power limiter

I am interested in constructing my own version of an RF power limiter. There exist models such as the 11930A Power Limiter, but are very expensive. The intended use for the device is to limit input ...
0
votes
1answer
65 views

Few doubts about turning an atx psu into a bench lab power supply [closed]

First, thank you for your time of reading my questions. As the title suggested, my questions are about turning a computer power supply into a lab power supply. I already did my homework and read ...
-4
votes
0answers
38 views

Power Mosfet and IGBTs

Can somebody explain me the difference between power semiconductors and traditional ICs..and within power semis the difference between IGBTs and Mosfets. a detailed answer would be really ...
1
vote
2answers
88 views

Battery life: 2xAA or 4xAAA - which is better?

Which will provide longer battery life: 2xAA batteries in series or 4xAAA batteries in series regulated to 3V via a voltage regulator or buck converter?
1
vote
2answers
104 views

Help in the design of a super low power device

I'm building a wireless device that have to last with batteries as long as posible. The device has an rf module with a microncontroller that manages the control, that part is bought and works fine. ...
1
vote
2answers
39 views

Calculate power supply for step down modules

i'd like to build a system in which there will be step down modules that get their power from an ac-dc converter. there are 5 modules connected to the ac-dc converter (each of them steps down to ...
-3
votes
4answers
81 views

Can I power a 110VAC heater with 230VAC [closed]

Can I give power supply of 230VAC to 110VAC heater? What is the effects on giving higher voltage on heaters?
0
votes
1answer
45 views

A single pump controlled by a VFD

We're testing a 110V single phase Variable Frequency Drive(VFD) connected to a single pump having randomly let's say: R= 10ohm, L= 50mH. And I am putting these numbers to fiqure out the relationship ...
1
vote
2answers
70 views

Two power supply units, equivalent settings, different results, why? [closed]

I recently bought a 3d printer which runs on a Melzi v2 board [http://reprap.org/wiki/Melzi]. It came with a 12V 20A power supply unit (multimeter readings showed values ranging from 11.8V-12.1, im my ...
2
votes
2answers
81 views

What resistor should I buy (More than 2kW peak power)

Im using a resistor (68Ohm) to discharge a capacitor bank rated at around 400V. This is the graph of the current and the power in the resistor, as you can see there is a 2KW (4.5A) peak. But it's just ...
-2
votes
2answers
59 views

Starting current of an induction motor

How to calculate the Starting current of an induction motor if I have the power in kilo watts and the voltage? I have looked up formulas , but I got confused. I calculated the full load current by ...
0
votes
0answers
32 views

Circuit error: Possible reverse current in the circuit

Imagine the system: 1. Power supply connects to CAN EGSE 2. Through DC/DC converter, EGSE provides converts 28V to +15, -15, and 5V outputs 3. The outputs go to the module Note:EGSE provides CAN ...
0
votes
1answer
104 views

How can a speaker have a higher output power than input

Looking around the internet, there haven't been many answers to this questtion. Here is one which doesn't fully explain it: Power input smaller than output? How can this be? So I am confused. I know ...
0
votes
1answer
36 views

Undestanding the SOA of MOSFET from the datasheet?

I was checking my MOSFET for the selected power class. Could somebody explain the decoding of SOA of the MOSFET from the datasheet specs. I want to know which regions are considered during the ...
4
votes
1answer
262 views

What is a good process to replace a discontinued part?

I have been looking about (on the web and printed catalogs) attempting to replace a part that is now discontinued. The experience has been part success - and part failure. A part is available to use ...
1
vote
1answer
42 views

Circuit for controlling 3 DC motors

I have a simple 3 motor robot arm. Without much experience or knowledge, I put together a circuit for controlling it. Circuit is below: Now the circuit actually works and I can program the Arduino ...
2
votes
1answer
98 views

Why do graphics card power cables (PCIe, etc) use more than two wires?

High-end graphics cards need more power than can be delivered through the PCI slot. One option would have been to deliver the extra power using a 4-pin Molex or SATA power connector, but recent ...
1
vote
2answers
74 views

How can I detect which DC power source to send to an underwater camera housing?

I have a small problem and hoping someone can help: I am trying to design and build a reasonably universal underwater housing for some different cameras. there is a breakout box on the surface and ...
0
votes
0answers
10 views

Determine which component failed on a motherboard [migrated]

Laptop powers up from the battery but it does not from the charger and it doesn't charge the battery either. I have measured voltages on power circuit components (see in the attached image). ...
-4
votes
0answers
34 views

How do I know what kind of adapter to purchase for my equipment. Amps? Volts? Both? Thanks [duplicate]

I have an old bulky adaptor mean to power 2 items. I only have 1 of those items now that needs to be powered. I want a new, smaller more portable adapter. What info do I need to buy a replacement. ...
0
votes
3answers
87 views

Producing electricity from heat on a small scale?

Using a small solar panel like in the following picture we can produce around 0.935W of power with a peak voltage of 5.5V and current of 170mA under good sunny conditions Does a similar type of ...
0
votes
0answers
24 views

Arduino + 4051 -> noise on certain 4051 pins

I am trying to use two 4051 ICs with an Arduino Micro right now. The idea was to have an 16-sensor demo station (8 sensors per ...
1
vote
2answers
58 views

Determining which power supply is connected to our circuit?

I am designing a small dongle that will have features either enabled or disabled as a function of the supply voltage. I want the device to be low-power and run, for the most part, off a 3V coin-cell ...
0
votes
0answers
17 views

garbled characters display in Power System Analysis Toolbox (PSAT)

I've tried many versions, it still didn't work, does anyone else have similar problems before? Thanks very much!
0
votes
1answer
45 views

How battery-charger system in mobile phones and laptops works?

It was 5 am in the morning stuck at McD and waiting for the train with my friends. All out of nowhere I asked them this question that I have been thinking about for some time. How this ...
0
votes
2answers
160 views

wiring a 3 position toggle switch for two devices?

I am building a plastic vacuum molding device that requires a heating source and a vacuuming source. For safety reasons I want to install an On/Off/On toggle switch so I, or whomever, am forced to ...