Questions tagged [power]

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

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1 answer
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Voltage modulation circuit

I tried to simulate a modulation circuit which uses a comparator, following this video. The output I get at the 1 kΩ resistor is weird; it should be the same shape as the send signal above. May I know ...
1 vote
1 answer
52 views

Masking tape on 12v car charger adapter a fire hazard? [closed]

I recently purchased a 12v USB car charger adapter (for context https://www.bestbuy.com/site/anker-powerdrive-2-alloy-24w-vehicle-charger-silver/6479184.p) to power my phone. Due to vibrations, the ...
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1 answer
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Does peak mains power consumption of a laptop chargers depend on input or output parameters? [duplicate]

Disclaimer: I do understand that depending on the load the "power adapters" or chargers would pull a completely different values, so this question is about the theoretical "peak". ...
0 votes
0 answers
26 views

Solar charging- battery overcharging due to resistance of path voltage drop

I am trying to implement Solar charging for cells using LT3652, as mentioned by one of their modal circuit The circuit works for multi-cell chemistry while charging till the VFB voltage reaches a ...
0 votes
1 answer
111 views

Do DC-DC converters have a power factor smaller than 1?

Say I have a boost converter (picture below) that accepts a constant DC input and outputs a constant DC signal. Does this system have a power factor (PF) that is smaller than 1 (because the circuit ...
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5 answers
103 views

Could someone explain why reactive components like the inductor and capacitor are needed in circuit? Can't they be avoided? [closed]

I just don't get why they the inductor can't be avoided. It's this same Device that causes reactive power. Could someone explain why reactive components like the inductor and capacitor are needed in ...
0 votes
0 answers
32 views

Power dissipation vs. heat dissipation for transistors and diodes

Are these two concept the same or different for semiconductors? Some power MOSFETS have power ratings in the hundreds of watts, and that's way too high for heat loss. I try to understand 'power ...
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2 votes
0 answers
51 views

Diode conduction angle for inductive and capacitive load [closed]

I need to calculate the conduction angle of the below circuit in two cases: A 1 μH inductor as load as shown in the figure; The inductor is replaced by a 1 μF capacitor. My source is a 10 V peak ...
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2 votes
1 answer
56 views

How to match the pin of this IC in LTspice?

Refering to the datasheet here, I find it hard to predict the names of the pins because the names are different for these 2 pictures. Is C0 the same as CE, and should CLK_INH be left floating/...
0 votes
0 answers
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What is the difference between Inertial Response and Primary Frequency Response in Power system aspect?

What is the difference between Inertial Response and Primary Frequency Response? In literature, some times they used as interchangeably. How can I differentiate these two terms? Specially in the case ...
4 votes
1 answer
67 views

Minimum USB-C power in order to recognise device?

My setup: I have an ESP32 IC (and some circuitry around it) which is powered by USB-C or external power. These two power inputs are "mixed" together using 2 Schottky diodes. (GitHUB repo for ...
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2 votes
3 answers
609 views

Why doesn't this Wien Bridge oscillator work?

See the circuit. I am running this from a 24 V supply. I need it to oscillate at about 700 Hz. Does anybody see anything wrong with the circuit? I have spent about 3 days trying to figure it out, but ...
7 votes
2 answers
808 views

What happens if high via current flows in PCB?

If I used a via of 8 mils diameter with 20 um thickness. As per sierra tool calculator it can carry current of 1 A at 10 degree rise in temperature. What happens if the current is more than 1 A? When ...
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1 vote
1 answer
118 views

In the output feedback loop of a DC/DC switching power supply, how much bandwidth do the operational amplifiers need?

I think the title says it most - I was wondering how much bandwidth is needed for the amplifiers within the analogue feedback path of a DC/DC converter? I am having some issues with my design where ...
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1 vote
1 answer
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Can a single device connect to two different power outlets?

I’m designing a desk with electrical parts onboard that need to be plugged into a wall outlet. I’d like the desk to have two power inlets that can plug into the wall—one on each side of the desk—so ...
3 votes
3 answers
314 views

How does the PFC boost circuit work?

I am reading TI's PFC Circuit Basics, and I am having a hard time understanding how the active PFC boost circuit works. I understand that ordinarily the current waveform is not in-phase with the ...
1 vote
1 answer
52 views

Why shouldn't I use devices with motor capacitors with my remote controlled power plug adapter? [closed]

In the manual of a remote controlled power adapter (one of those that you plug into a power socket and switch on/off via the 433MHz remote control) it says that you should not use it with devices that ...
1 vote
0 answers
33 views

LoRa power level contradictions

I've got some LoRa boards that claim 20 dBm transmit power. They do indeed show ~100 mW output power on an old-school moving-coil RF wattmeter. However, on a spectrum analyser with 20dB + 30dB ...
2 votes
1 answer
79 views

Why does air conditioner power draw fluctuate during the day?

My air conditioner is controlled by a thermostat like most are. When the set temperature is exceeded, the system turns on the air conditioner using the R and Y wires of the controller. As I ...
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6 votes
5 answers
2k views

Confused about MW to MWh conversion

I have various datasets of energy production in MW. I need to present everything in MWh. I need to know if my data is already by the hour (logging a value for each hour of each day of an entire year), ...
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4 votes
2 answers
272 views

Is it perilous to route symmetrical circuits on different layers or with different trace lengths?

Given a common PCB size of 100mm x 100mm, sub-RF frequencies (<20 kHz) and non-sensitive signals (as opposed to as measurement H-bridge) is there a real problem in routing traces of a symmetrical ...
1 vote
0 answers
51 views

Ringing seen when charger is presented to DUT

The following is my setup: Charger is set to 56V and 15A. When charger is turned on there is significant ringing measured by the probe directly at the charger terminals. However this ringing is ...
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0 votes
2 answers
89 views

Method for always getting the sign of the power right

In a circuit setup like the one below, I'm asked to find the power at the voltage source. I did: $$KCL: I_V + I = I_R \iff I = I_R-I_V$$ $$I_R = \frac{V}{R} = \frac{1}{200} = 0.005 A$$ $$P_V = VI_V = ...
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0 votes
2 answers
90 views

Press same button 3 times to turn on an LED [closed]

Is there a circuit that can turn on an LED by pressing the same button 3 times? I have tried to search the web but found none.
0 votes
0 answers
45 views

Reset rain drop LEDs after it reaches a certain point

Referring to this YouTube video, this CD4017 is connected to 10 LEDs to produce a rain effect. May I know how to reset the entire circuit after, for example, 23 times of rain drop effect (each LED has ...
2 votes
1 answer
71 views

How to design an auxiliary power hot swap controller?

I'm designing a system that has to sit out in a field for days with no access to power mains. It contains a computer, low speed motors and a few sensors. Power info is 29V nominal input (8S Lipo), 15A ...
2 votes
2 answers
56 views

Can regular ON/OFF solenoid valves be turned into a proportional valve just by changing the control electronics?

I was wondering whether it was possible to make a proportional valve out of a regular ON/OFF solenoid valve by characterizing the current vs the flow rate and then driving the solenoid using a ...
0 votes
0 answers
68 views

RF low-power limiter

I have designed an RF front end in the 915 MHz ISM band. This front end is for two radios that interface with an SDR. The TX portion of the front end will transmit 3 W. My problem is that after doing ...
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0 votes
2 answers
67 views

Cutting a 1500 W heating coil into two halves and using one half for a project

I have a heating coil (Nichrome coil) of 1500 W working at 230 V. I need to cut it into two halves and use one half for my requirement at 230 V without burning my coil. I know that if I use half the ...
0 votes
1 answer
48 views

How do I calculate the electrical power of a BLDC motor?

I used a current sensor to measure the current of one of the motor phase lines (Iphase or Iline?), and used a voltage sensor to measure the voltage between two motor phase lines (Vline-line). With ...
0 votes
2 answers
80 views

Help identifying a female power plug (500 V - 16/25 A AC - 3 pins - France)

Can you tell me what kind of plug this is? I suppose it's from the 60's but I am absolutely not sure; it may well be more recent. Are there adapters to allow connecting regular 220 V devices to it (...
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-1 votes
1 answer
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Connecting multiple Raspberry Pis to the same power [closed]

I am trying to make a smart fridge. In the fridge, I have 4 shelves. Each shelf has a Raspberry Pi 4. I don't want a mess of cables in the fridge. Because of that, I want to make a power module (or ...
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0 votes
1 answer
69 views

What is the "Smart Battery Connector" for 9V rechargeable batteries?

I'm looking for a battery charger for 9V rechargeable batteries (must be switch-mode, not linear). I came across the "Smart Battery Standard Connector" structure in a controller IC datasheet ...
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0 answers
51 views

How to calculate voltage noise density and RMS from power spectral density

I found an interesting paper for an ultra low noise voltage reference. They show a power spectral density plot: I now want to compare these measurements to a standart voltage reference. They are ...
-2 votes
1 answer
121 views

What happens if you put a 100 Ah battery on a 48 V, 1500 W motor? [closed]

I got a 48 V, 1500 W hub motor kit to put on my bike. I also bought a 48 V, 100 Ah battery that constantly releases 40 Ah. How long will it last? How fast will the bike go? Is it safe to use?
0 votes
2 answers
108 views

How to power a 3V motor with AC?

I want to power a 3 V motor continuously for product demo purposes. Currently, the product is powered by 2 AA batteries. I would like to change the power source so I can plug it into a 120 V wall ...
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1 vote
1 answer
96 views

Identity a QFN chip

I would appreciate your help in identifying an electronic chip in a QFN package with 24 pins that belongs to a Roland R-05 sound recorder. The component is located near the DC/battery input and I ...
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2 votes
3 answers
838 views

Total voltage of six 12V batteries in line

Total voltage of six 12V batteries in-line A golf cart has six 12V flooded batteries in line. Each battery has six cells (six flooded holes for maintaining levels with distilled water.) Each hole or ...
1 vote
2 answers
128 views

Two similar voltage sources equidistant from a load in opposite direction

I have two 52 VDC voltage sources, each an equidistant of 200 m from my load. For this purpose, take it as one voltage source is coming from the east and the other from the west. Along the 200 m path ...
8 votes
5 answers
3k views

What may happen if I leave out bypass capacitors?

I'm using the KSZ8081RNA/RND 10BASE-T/100BASE-TX PHY with RMII support. This is the hardware design checklist of the IC. On the page 2 of the checklist, there is a power supply connection figure. What ...
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0 votes
1 answer
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Why is there continuity between the output terminal of my DC power supply and input terminal of RAMPS 1.4?

I have a 12V, 15A power supply. Using a multimeter I found that there is continuity between the output terminals (2 positives and 2 negatives) of my power supply. Also, I did the same test on my RAMPS ...
0 votes
1 answer
70 views

12 VDC to 6 VDC to power a radio [duplicate]

I have a Grundig radio that requires 6 V and 500 mA negative center pin. It is very sensitive to noisy wall warts, so I want to power it from my very noise-free ham radio 12 V power supply. Can I use ...
2 votes
2 answers
365 views

I built a DIY DC-DC buck regulator. It's getting extremely hot. Why?

I am really scratching my head at this. I don't see anything wrong with my circuit but my regulator gets EXTREMELY hot while in operation. What I'm building is a USB phone charger for my e-bike as ...
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1 vote
3 answers
121 views

Buck converter adjustable output-voltage using digital potentiometer [closed]

I am trying to design a buck converter using an LM2576HV (Vref: 1.23 V) and a digital potentiometer (input: 48 V, output: 0 to 48 V, Imax= 3 A). The digital potentiometer with the highest supply ...
-2 votes
1 answer
90 views

What's the difference between P = 5V x 3A and P = 3V x 5A? [closed]

What's the effective difference between power(W) = 5V x 3A and power(W) = 3V x 5A?
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1 answer
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Glass cartridge fuses, what does the "P" suffix mean?

The IEC 127 standard for glass cartridge fuses ends with a voltage rating, "###V". I have a fuse with a "P" suffix after that, what does this mean?
0 votes
1 answer
32 views

Battery Charger and power supply DC-DC with noisy input

I have sort of a weird question I'm hoping folks here can help with. Have searched other questions but not found a similar-enough one that applies. I have a large mechanical system which travels over ...
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0 votes
0 answers
15 views

Minimum and maximum input power level of clock buffer

What is the minimum and maximum power level(dB) that can be applied to [ADCLK846BCPZ-REEL7][1] chip? In the datasheet it is mentioned as below:- Input level:-1.8Vpp ...
-1 votes
1 answer
74 views

Calculate the power consumption

I have project put the ESP32-S2 in active mode for 10 second and then go to modem-sleep mode. I want to compute the power consumption for the active mode. According to this, the ESP32-S2 current ...
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0 votes
1 answer
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Via stitching in PCB design

I am a newbie in PCB designing and started designing PCBs recently. I came across a concept called via stitching which is to achieve increased current carrying capacity of the board. I looked for the ...