My cousin called me from Sacramento, CA and said super markets and big box stores are out of toilet paper and certain brands of bottled water cannot be found. Other necessities were also missing.
Here in Virginia, my local Costo was packed with people also buying up all toilet paper. Lines...
I have read pros and cons for both, but would like to hear what people have to say. I can build a simple power supply for a project that supplies 15v that is isolated from earth ground by using the output from a step-down transformer. I can also put one together that shares earth ground.
Which...
I have a situation that I cannot explain so I need the assistance of someone with a good understanding of thermodynamics.
I have 36 AC to DC power supplies located in an equipment rack. These power supplies are failing after some time. The failures appear to be moisture related. We put...
I was wondering about the possibility of Induction heater powered by Bicycle Dynamo (alternator/generator) without using any other circuit element. Which means connecting 24 V 50 to 60 HZ AC to Coil with turns around 100 in pancake shape (10 inch diameter ) and Stainless steel plate of 3 mm...
I have a Multicomp 0-30V 0-5 amp power supply. I did some tests using it as a battery charger. It worked very well the first few times, then I accidently hooked it up backwards and killed it. There was light sparking when this happened. No fuses blew. It powers up normally, and I can...
A shortage of carbon dioxide (CO2) in the U.S. is leading to complications at a number of breweries and food suppliers across the country.
https://time.com/6215461/carbon-dioxide-beer-shortage/
Denbury Energy issued a statement that the contamination was a "minor issue", and they maintain...
Why do some UPSs have both Volt-amp and watt rating? According to APC, the connected load shouldn't exceed the UPS's VA and watt rating. Why? If I had a UPS with 1000VA and 500W rating, why can't it power a load consuming 1000VA @ 900W? If a UPS can output 1000VA, why does it care how much...
Along with the endless complexities of life and the evolution of life, it occurs to me that at all points there had to be enough available nutrition for existent life forms - and that food supply itself had to go through a process of evolution. It seems self-evident that the environment of early...
The equation for supply should be this-:
y=mx+c
S=m*Qty+c
=c+d*Qty
Why is P used instead of Qty?
I understand that supply increases as price increases relation is used here, but I just want to think graphically. This looks wrong according to that.
Hi,
For years I wanted to understand why we have a 3 phase supply and not a 2 phase supply in AC. In Quora I found an interesting answer and was convinced about the purpose mentioned:
Answer to Why there is no two phase electrical inputs instead of three phase and single phase? by Paul...
I'm currently making a solenoid valve for a home project, I've been testing the solenoid with a DC Lab power supply, I have set the desired 12V but after connecting it drops and I get a high current with a small voltage.
I understand that it will only draw the voltage required to push the...
I am confused with the negative voltage supply connections in electric circuit. If i have circuit as below with -5V source
it is same as below
In the 2nd circuit the 5V is directly shorted with the ground, does it mean the circuit is not correct? Am i missing something? Please advise.
I have held the assumption that batteries supply electrons at the negative terminal and absorb electrons at the positive end for many years. However, after watching this video at about 3:30, it is said that batteries do not actually supply charged particles but that the battery only creates an...
I am using a power supply (30 kV, 20 kHz) to discharge in air between two electrodes separated by an insulator. For 30 kV applied voltage, oscilloscope shows only 6 kV, and no discharge occurs. What are possible problems and solutions?
I check the datasheet of LM 319 high speed comparator online. I was wondering if LM 319 can accept negative supply voltage(-10V) and its possible to produce a 10V to -10V square wave which oscillates along origin rather than just 10V to 0v as shown below.
In a plasma device, the plasma is generated by applying high voltage in a gas. What are the specifications for the power supply producing such plasma?
The output must be AC or DC? Pulsed or not? What are the current, voltage, etc...?
Yesterday the batteries died on my key fob and I didn't have the appropriate batteries to replace them. I thought I could use my power supply to operate the key fob to open the car door but it did not work. I thought that it may be caused by a noisy power supply at the higher frequency range of...
About 0.38 Myr after the Big Bang, the universe cooled to about 3,000 K and went through the recombination era. Electrons and protons combined to form neutral hydrogen atoms and the photons became free to travel through space.
The freed photons can be considered as photon sources of a small...
Hi,
I have a question, I think the answer is no you can't do it, but I want to know why.
First mains supply - 3phase N + E (50hz)
Connected to this first supply is an inverter that gives out a 3 phase 415vac @60hz (no neutral) second supply.
The 60hz inverter output feeds 3 independent tapped...
Please don’t laugh, this may sound a trivial question, but it is important. I have seen so many conflicting opinions, even from manufacturers. Some say, just use the biggest bore possible, others say use a small bore 8mm for a fully pumped system & a large bore 11mm for a gravity system. There...
I have to use a BLDC motor combined with a BLDC motor driver (X-NUCLEO-IHM08M1)
The motor has a rated current of 7.3A. So i am planning to use a 36VDC 13.9A power supply (SMPS).
The problem is that the PS that i want to use has a "HICCUP mode" for overload protection and not a "constant current...
Yes, this is a question. I already converted an old PC power supply (350 Watt) to replace the bower bricks for my Internet modem and router. What I would like to do now is install a 2-3 hour mini-UPS in the mix so I can remove it from my computer's UPS.
I have spent days online scouring the web...
I need to create a 5 V stable DC supply out of 6 V AC from a transformer. By "stable", I mean that I do not want the ripples in the voltage that one gets from the output of a full-wave bridge rectifier. I have to feed this to two ATmega 8A μCs.
I am going to create the following circuit:
6 V...
Find the supply voltage of a ladder circuit shown, so that I=7A. Assume R=11Ω. (The unit must be placed)
Hello, everyone. Please, help me with this. Could someone explain to me how to solve such tasks. I literally spent the whole day watching Khan Academy and trying to figure out how to solve...
I want to mount a camera on the front of a tractor(Sony RX0M2, similar to a gopro). The camera will eventually be used for image processing. A PQ-12 micro linear servo (see here) will be used to turn the camera on/off. It is being run by a Raspberry Pi 4B. All components in this project will be...
Hi, friends,
I have two queries.
I read somewhere that
1. In class B mode higher plate efficiency (tube amp) permits the use of smaller power supplies...and
2.For low level signals a low voltage supply is used, but as the signal level increases, so a high voltage supply is utilised.
Q1. what...
A few years ago, I bought a Accurite weather station which has a wireless connection (not wifi) to a unit in doors. I was standing near it on a quiet sunny day and I heard a motor running. It turns out that is's a fan that blows over the temperature sensor to make sure it measures the actual air...
I know only these relevant equations for power. But here there is a different situation, we have a parallel plates which we don't have to know I current. How should I think of about this? I wonder if it can be thought of a capasitor or something?
Assume that also we know E, B and velocity .
How can Vce vary from 0 to 2Vcc? In class, I learned that it was due to Lenz Law working in the transformer and a voltage of Vcc being induced to reverse the change in Ic. However, I cannot picture this. Can someone please explain with a diagram of how this comes about in the transformer windings.
I know how to calculate the power output and input by analyzing the current in put and output with multimeters and using the formula P=VI. But P_out is obviously incomparably smaller than P_in so the efficiency would suck this way. Is there a better way to do this??
In AC-DC power supply modules, having non-isolated power converter topology may result in input "Line" (hot wire) been assigned to "Vss" (lower voltage rail) at output of power supply module, and N (neutral) assigned to Vdd (upper power rail). Inside single system, this usually does not results...
Hey everyone,
So I'm trying to figure out what could be causing this problem:
I have a DEWENWILS Wireless Remote Wall Switch which takes a 12V battery 60 mAh(23A battery), when I replace the battery with a 12V 500 mA DC power supply, the unit stops working properly. I'm able to use the Power...
My first idea was to find the total impedance of the circuit, but I think viewing the two parallel resistors as one resistor of 0.5 Ohm isn't the correct way? I don't know how to simply this series / parallel circuit further to find Z total.
Then I tried to use Kirchhoff's law to the loop on...
Hi, I'm graduating with a PhD in ChemE. I'm interested in a position in industry that is not purely technical and that will have some exposure to the business/leadership side.
I have an offer at a F500 company to be a supply chain engineer. The job will entail working with Asian suppliers and...
Summary: Hi there
On a 12VDC transformer we use at school. Is the positive terminal +6V above ground potential and the negative terminal -6V below ground potential?
Thank You
Hi there
On a 12VDC transformer we use at school. Is the positive terminal +6V above ground potential and the negative...
So I've basically built a robot that has a lot of servo motors. 14 of them can draw up to 3 amps each(max)(usually 1 amp average) at 4.8 to 7 volts.
What's my best option to power it? The power source doesn't need to be connected to the robot, so weight shouldn't be an issue.
My best guess is...
Why when we supply energy for biological body then the body can keep entropy not increase?Because we know that by definition temperature equals partial derivative of internal energy to entropy.So that when temperature being constant,if internal energy increase(supplying energy for body) then...
Hope you may help me to understand how detrimental to compressor motor would be if it operated at voltages exceeding the manufacturer's specified 400V by 12%? so 448V.
I have vendor engineers saying since it exceeds 10% they cannot safely run the plant and of course the voltage monitoring relay...
I am trying some projects that involve building some very simple electrostatic motors. I attached below figures of the kind of electrostatic motors I am trying to make. What I can't figure out is what kind of high-voltage power supply I should use, presumably 1000 to 10,000 volts is what these...
This is for safely powering up devices being tested/repaired. Supply is 240V rms single phase, protected by 32A MCB and 30 mA RCD/GFCI, then fused at 13A.
There doesn’t seem to be a consensus online, and my EE and repair books just say I need both, without specifying order.
I think the...
Hi there,
I have a query about electric power in AC systems. I am Chilean, and over here the power supply is 220 V (rms) at 50 Hz. Some countries use voltages in the range 200-230, but others use 110 V or so, at frequencies of 60 Hz. There is no uniqueness, but all work. My question is...
hi everyone.
my uncle currently has a big "cylindrical rolling cooking pot" (imagine a cement mixer with burners at the bottom) that he uses to cook his stuff, ie sesame seeds.
this cooking pot currently runs on gas.
as he has been facing some issues with the gas supplier, he intends to...
I see that DC power supply have voltage between it's + & - and its 24V.
However, there is no voltage with ground.
I don't understand - if device's "point" has some potential, why doesn't it give some voltage with ground (which has ~0 potential)
I tried this with phoenix contact...
Hello!
Is the blood supply to an organ done exclusively by one (or more) distinct arteries or there is extensive collateral supply from different arteries?
For example, is lungs' circulation only from bronchial and pulmonary arteries/veins or there is collateral blood circulation as well from...
I'm looking for a high voltage power supply. I have no experience with such a power supply, nor with all the terms or specifications used for such tools, so I'm looking for general suggestions to what to look for.
I want to generate an electric field or potential field between two points a few...
Hello, I have recently converted an old bluetooth speaker into a Aux input device for a guitar amplifier. You can see how I converted it here. So now I'm trying to power both the bluetooth device and the guitar amplifier using the original amplifier's power supply.
Here is the power that each...
Hello,
I understand that a bench power supply (see picture below) is mainly used as a constant voltage source: once the load is connected to the two terminals, we set voltage ##V_{supply}## by turning the voltage knobs on the right and find that voltage across the load. At the same time, the...
Hello and good day.
I am currently involved in research that seeks to utilized a Walker Scientific power supply and magnetic. The system is old but functional. We seek to utilize the magnet in order to conduct some low temperature experiments. We need information on this power supply, of which...