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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.

0
votes
1answer
37 views

Low power design, choosing correct buck-boost converter for LiPo battery

I want your opinion on subject considering low power applications. I want to build basic loraWan tracker with Murata Lora module(3V3), and I want to use LiPo battery. What Im struggling with is power ...
0
votes
1answer
55 views

One wire AC power

I would to connect a nodemcu board (powered by 3.3 V) to AC power behind the light switch, but I can use just one AC wire (the one that opens/closes the switch for light). Is it possible to do that ...
-1
votes
0answers
22 views

DATAQ Data acquisition device power connector [duplicate]

I got hold of a DATAQ DI-710 data acquisition device. The device was delivered with an AC-adapter. According to the data sheet, the device can be connected to any 9-36VDC however. The only problem is ...
0
votes
0answers
46 views

Using circuit breaker instead of a fuse

I am making a contraption that uses an atmega328 to trigger a water pump to water the garden plants on a schedule. The controller will run on low power mode to sleep all day and wake up to water the ...
6
votes
2answers
1k views

Power Transformer: 110V and 220V input, with two 15V outputs 180 degrees out of phase

I have never designed a power supply before and have a few questions and would appreciate any help. Firstly, I want to use a transformer that can both take 220V and 110V inputs. Can I use a center ...
0
votes
1answer
71 views

Is this cheap extension cord safely rated for 1625W?

Comparing two cables that I have, a cheap extension cord and an expensive "heavy duty" extension cord, both are rated for the same load. Is this an inflated rating or is it accurate for the white ...
0
votes
1answer
30 views

LC filter applicability for power to output cables

I am designing a circuit that has a 240MHz MCU and some cables going to sensors so I am wanting to reduce the clock noise getting onto the supply line and going out the cables by using an LC filter. ...
1
vote
3answers
91 views

Resetting CD4017 Counter when power source is OFF

I found the circuit below online and I have two questions about the reset switch. Does it help to click the reset button when power is OFF? I mean, does it clears the memory of the CD4017 chip when ...
0
votes
3answers
107 views

What is this component on circuit schematics? [duplicate]

It's a resistor like coloured 2 pin component from a power supply board of a home theatre, with a glass-transparent aspect. I'm a hobbyist and not into complex circuit till now... looking for an ...
3
votes
1answer
79 views

How can i add voltage regulator to unregulated DC adaptor?

I would like to add L7809 voltage regulator to an unregulated DC adaptor,as it is shown in the photo. In the data sheet,there is a figure for application circuit that included 2 capacitors(bottom ...
0
votes
1answer
56 views

How to calculate maximum amount of bulbs I can connect in parallel to match design specification of 1.5 A?

I'm designing a sensor triggered circuit that involves 220 V passing on a PCB, so I designed the board thickness to withstand a maximum of 1.5 A. The main load on the circuit would be a series of LED ...
0
votes
1answer
27 views

What is the reference for High side IC with internal mosfet driver

In the schematic below (like many other) the IC (switcher) is on the high side. I was really curious how the internal circuitry of such an IC is referenced to. My first thought was that everything ...
-1
votes
1answer
44 views

Tumble dryer heater element [closed]

The heater element on my tumble dryer died, ordered a new one using my model number etc. The problem I have is that the original element is rated 240 V and 1050 W, the replacement sent is 240 V and ...
4
votes
2answers
119 views

Flyback Converter Capacitor Value selection with given ripple voltage limit

I need to design a flyback converter for my project. In my design the output voltage is 15 V. I calculated all the parameters including inductance values, diodes selection etc. However there is a ...
0
votes
1answer
57 views

LDO Voltage regulator output unexpected Voltage drop

I have a circuit using LD39015 1.2V Low Drop-out voltage regulator. . The value of VCC is 3.3 Volts. The goal is to supply an ADC channel with a constant stable voltage so I can use that to ...
3
votes
1answer
74 views

5v power switcher: Uninterruptable power source

I know there are a few other questions similar to mine, but after looking through the answers, it does not seem like it's what I need. I've also looked at the Arduino Due/Uno circuitry, and they aren'...
0
votes
0answers
33 views

Current and power ratings of components for pulsing current

I want to put together a circuit that will pulse 40 A of current through at inductive load pushed through by 80 V. Cost is a factor for the design and build, and I would like to know what I could ...
1
vote
0answers
18 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 ...
-1
votes
0answers
23 views

Output current handling for TC1044S

I'm reading the TC1044S charge pump datasheet to create a negative dc power from a +5v supply. But I can't understand how much current this part can deliver. Can I power multiple opamps with a single ...
2
votes
1answer
74 views

Power Dissipation of Op-Amp

If we look at the output stage of the MP111 op-amp it's just 2 MOSFETs in series. I'm curious why the power dissipation of the device isn't simply \$R_{\text{ds(on)}} \times I_{\text{out}}\$, but ...
1
vote
2answers
227 views

Rough estimation of power consumption in an electronic design [closed]

I want to get a rough estimation of the power that my design is going to need. Is it sane to calculate the power of every IC component based on values in DC Characteristics in the corresponding ...
-2
votes
1answer
54 views

Inductor power choke

I'm looking for this inductor 10 µH. Need help to recognize series model of this IC's inductor.
1
vote
1answer
41 views

LED strip power requirement [closed]

I have an approximately 1 meter LED strip in "warm white" running from a 2 amp power supply for some time now with no problems. I want to add another strip, of about 2 meters, to this same power ...
0
votes
1answer
36 views

I have a H07RN-F 3G cable which is rated at 400V/16A, can it be used for a normal 220V schuko connection without consequences?

Basically making it a 2.5mm gauge cable, will it have any negative effects on appliances that run on 220V - I am not sure if a 400V/16A rating is the max or the supposed to be used at/for rating?
-1
votes
0answers
28 views

Generator RPM and Energy Relation

If a 3 phase AC generator rated 5 kW @300 RPM generates 5 kWh in one hour of continuous operation, is it possible to find how many rotations of the generator at 300 RPM will generate 10 Wh? Thanks in ...
0
votes
1answer
64 views

RCD tripped when measuring with a scope

Below was my setup: The moment I connected the probe the RCD tripped. My scope was earth grounded. Does that mean I shorted the neutral and the earth ground? I know that neutral and earth are ...
0
votes
1answer
36 views

Calculating true output of LED

I'm trying to figure out the true output of the individual LEDs on this panel: https://www.amazon.co.uk/gp/product/B01M10RZ98/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 It's a 96 LED infrared ...
1
vote
1answer
29 views

Forward Converter - Voltage through primary winding Question

So my waveform is a step function, where maximum voltage is at Vin = 40V, and minimum voltage is (-N1/N3)*Vin = -200V. The minimum voltage doesn't sound right to me, so I was wondering if anyone can ...
-1
votes
3answers
78 views

Oven power usage estimation [closed]

Does an oven draw less power when used at a lower setting? I'm trying to calculate the cost of running my oven on the lowest setting as a dehydrator. Wattage is 4800 kWh/cycle is .92 and my cost for ...
-1
votes
0answers
29 views

How to specify an “external enable” (buffer) chip for a current-hungry peripheral

I have a design with a simple quadrature optical encoder as one of my system peripherals. I'm working on reducing my power consumption in the "idle" or "off" state and the optical encoder draws 18mA ...
2
votes
1answer
90 views

5-10 second backup for wifi router during power cut

In India power cut is often. And most houses are installed with Inver-battery, for backup till the power comes back. But since all inverters don't behave as ups, there occour a little gap between the ...
0
votes
1answer
64 views

Good PCB Design - Single Power Plane with 2 Power supplies (+ve & -ve)

Recently I've taken over a project which requires low noise but the design given to myself does not meet the requirements. I noticed on the PCB design It has a single Power Plane with 2 separate ...
0
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0answers
33 views

Equal Voltage, Higher Wattage

I am attempting to make a solar powered fan for my room. I am going to be using a 9V DC motor to spin the fan axis, and I have my choice between different 9V solar panels. My question is this: If I ...
1
vote
1answer
41 views

Does Reactive Power flow between Energy storage elements in a three phase system?

I noticed that unlike the single phase ac power sources, the power in three phase is constant which means the instantaneous power is the same as the real power which is $$3V_{rms}I_{rms}\cos{\theta}$$ ...
0
votes
3answers
108 views

Resistor selection based on power rating

For example, I have a cicuit of single resistor R = 2k, apply with Vdc = 18V. The Power of the resistor is about 162mW. Should I pick a resistor with higher Power rating (Eg 0.25W 0.5W) or lower ...
0
votes
1answer
70 views

Interfacing coin cell back up for internal RTC of ESP32

In esp wroom-32 all the VDD pins has a common connection. It includes VDD_RTC too. So in case of power failure if I switch the power between main DC source and coin cell using a mosfet, will it create ...
1
vote
1answer
38 views

Max power draw on voltage rails of mini PCIe Card

I am designing a custom mini PCIe card. What is the max power I can draw from the 1v5 rail, and the 3v3 rail?
0
votes
1answer
151 views

Finding a CPU's Capacitive Load - Computer Architecture

I'm new to computer architecture, and found a question similar to that on this site already with actually quoting the same text book. I'm struggling to figure out if the answer is 1.77Ghz or 3.55Ghz. ...
0
votes
1answer
41 views

How to size transformer for a circuit?

I am using a 5 Watt PCB mount AC/DC power module with universal input(85-264 V) and output as 12 V. The cost of the module is very high so thought if we could replace the module with a PCB mount ...
0
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0answers
17 views

How does one calculate wifi interference per channel?

If you've ever lived in a dense residential neighborhood, I'm sure you've come across the problem of finding the best channel to put your router on. Assuming there is no other non-wifi noise (a ...
-1
votes
1answer
54 views

Mainboards ATX “PWR_OK” signal fried [closed]

I've been struggling here trying to find out what exactly went wrong, but I just can't. I messed around with a power supply and decided to wire up my own with 3.3V, 5V, 12V and all other connections ...
-2
votes
1answer
40 views

DC generating plant [closed]

What would happen if positive terminal of Dc get grounded in any DC generating plant? Will it impact negative terminal and burn it?
0
votes
1answer
26 views

2A Brushed motor driver

I need to power 2 brushed dc motors with 2A each and 3 to 6V, one direction(no bidirectional or break). To the enable the rpi 3.3V pwm, and standard pins(breadboard), not those micro pins. I know the ...
1
vote
2answers
122 views

How many watt-hours in two AA cells?

If I wire 2 AA cells with a nominal capacity of 2 Ah and a nominal voltage of 1.5V each in series, then I'll get 3V with 2 Ah, right? Is that, thus 6 Wh? If I wire them in parallel, I get 1.5V with ...
0
votes
1answer
25 views

Line - Line voltage with different phase angles, amplitudes and frequencies?

I know that the mathematical equation for the calculation of Line - Line voltage with same frequency, same Phase angle, same Voltage of 3 lines from the same generator. now, i want to know ...
1
vote
1answer
118 views

Can someone explain how I turned on a circuit by touching it?

I was just trying to learn how a transistor actually works by tinkering around myself. I have an Arduino running a flashing light program. I hooked up an NPN transistor to test out how I can make it ...
0
votes
2answers
53 views

Are there any reasons I shouldn’t use a nodemcu’s 3.3v pin with this component?

I have this Hydrogen Sulfide gas sensor and the datasheet says the supply voltage requires a regulated voltage with a min of 2.6v and max of 3.6v I can’t find any datasheet for the nodemcu v3 (spent ...
1
vote
2answers
90 views

Transformer magnetizing inductance

I am learning about transformers and in the equivalent circuit the magnetizing inductance of the excitation branch is supposed to represent the current needed to "set up" the flux in the core due to ...
1
vote
2answers
90 views

Receiving power from antenna (Homework)

The question: "At a carrier frequency of 2 GHz, assuming a transmit antenna gain of 3 dBi and a receive antenna gain of 0 dBi, calculate the line-of-sight received power at a distance of 100 m from ...
1
vote
0answers
92 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 ...