A freeze in southwestern U.S. and Mexican fields has resulted in damaged crops and inflated prices for imported produce such as lettuce, broccoli and cauliflower.
Describe how this would be interpreted on a supply and demand diagram. Do not draw graph.
*Please include one(if you can) so I...
I'm trying create a battery power supply to create a portable modem. The modem runs off an AC wall adapter, and on it, its written to have 6V 1A output. My power supply needs to have the same output characteristics, but be battery powered. Can someone please point me in the right direction? Thanks
The demand for oranges is P=200-1.25Qd
The supply for oranges is P=-20+0.50Qs
a)find the equilibrium quantity
b)find the equilibrium price
c)what would occur if the market price was set at 150 cents?
Please help me get started or explain how I should do it as I have no idea where to...
I'm thinking of making a 200 led grow light using red and blue leds(5v). I have little knowlage on electronics. I was wonder if a computer power supply could be used and what other componets would be needed. I'm trying to get this built by late February to start growing my veggies (new project...
The UN reports that the World's food supply is dwindling rapidly while prices are approaching historic highs. http://www.iht.com/articles/2007/12/17/europe/food.php
Wheat has just hit a record high of $10.095 per bushel for March delivery.
What happens if next year's crops don't do well?
Hello All,
I am trying to run an electromagnet from my new power supply (TekPower HY3010E - 0-30V @ 0-10A). My electromagnet is a very simple air-core solenoid - 3-layers wound with 8 turns per layer from a 20-ft-long #12-gauge wire. The coil form is not big at all - a simple cardboard...
Hi There,
Right I recently did an experiment in Physics to find out the internal resistance of a lemon when used as a power supply.
We connected the lemon to a voltmeter, ammeter and variable resistor, changed the resistance on the variable resistance and measured the voltage and current...
Hello,
I opened up an AC to DC power supply today to see where they connected the Earth ground wire and I found that it's connected to the negative side (labeled V-) of the DC output. V- is also connected to one side of the transformer's output. Why would they connect the Earth ground wire in...
My Question is this-
We get AC supply to our houses, So for the first half cycle the current should from thro
the live wire to the load and then return thro neutral, Now for the 2nd half cycle this
must be reveresed, That is Neutral-load-Phase. This is wat is Alternating current.
But I...
Hi to everyone,
I would like to build a simple power supply, converting 230vac to 230vdc.
I have already purchased a full bridge rectifier rated @ 400v 35amps.
Q1) I would like to draw 5-10amps dc
Q2) Do I need to smooth the dc with a capacitor.
Q3) If So, what size and type of...
in relation to this thread:https://www.physicsforums.com/showthread.php?t=179898&highlight=psrr
is anyone savvy enough with bjt followers on SPICE to loosely guide me through the process?
Hello,
I'm trying to decide how to design the power scheme that will supply the various voltages within my project. The two big requirements are that there is a single main supply, regulated 5V @ 1A (typ. load .5A), and extremely low noise regulated 12V @ 1A (typ. load .4A). The low noise 12V...
So I'm trying to do some regulator PSRR tests and for this i'll need a regular DC source with a ripple on it (say 200mv pk-pk) so i can compare this to the ripple at the output and someone suggested this circuit set up to me. My question is about the capacitor, i was told "a signal generator...
Homework Statement
Hi friends,
We are working on a project for devloping a HIGH VOLTAGE POWER SUPPLY
Around 15 Kv for CO2 Laser.
Atpresent we have the power supply using 1N4007 that have a Vrrm (Peak
inverse voltage of 1000 V).We have uses 80 Diode in series as a diode bank.
To...
Hi, I'm technically a biologist so talk slowly!
Can anyone tell me, or point me in the right direction of a resource, that explains how you can change the frequency of an input AC source? e.g. in a "lab-pack" power supply.
Thanks very much,
Gareth
Hi,
I'm in dire need for help in my assignment. I have been asked , a), to research on a dual output DC power supply (Output = +15v and -15v) of not more than 15 components and to identify the different sub-sections that make up the power supply on the schematics. And, b), give an explanation...
I bought three LEDs, three 1k ohm resistors, and some wire. When I bought the LEDs, I made the person show me that they worked. He connected the negative end of the LED to the yellow wire, and the positive part to the resistor, which he then connected to the black wire. The LED lit up.
As far...
I just bought a 320w TEC to cool my processor. But the problem is, I can't afford a power supply that can provide enough amps through a single 12v rail. If I buy a power supply that has dual 12v rails, can I wire them together in order to provide enough amps to the TEC? I won't have anything...
what's the difference between AC and DC power source for solenoid valve?and what is mainly the power consumed for?
for mature products available, what should be taken into consideration for power design?
thanks
Homework Statement
A 12 V battery is rated at 200 Ah (Amps hours). How much total energy can it supply?Homework Equations
P=IV
The Attempt at a Solution
First I did E = 1/2 C V^2. (Got 4,320,000 J, although I'm not sure if that is correct). But now I need to convert it to kwh so my question is...
Homework Statement
If you have a supply line of water running from one tank to another tank.
And you started to drain the water out of one of the tanks.
Would the downward flow of water create a suction or low pressure in the supply tube?
. Relevant equations[/b]
The Attempt...
Hi,
I'm using a CPLD as an IO expander and I'm seeing +/- 200mV glitches with a 7ns period on the 3.3V supply (the CPLD uses this supply) when output pins are switched on and off. Based on the CPLD's datasheet the acceptable voltage range is 3.0V-3.6V. Are these glitches typical/safe or...
urgent power supply and creative inspire 2.1 2500 question
hello every one
this is urgent...
i am trying to fit computer speakers in a car
the computer speakers need 12V@ 2.9 A DC
the car battery is of 12V DC but of a lot more amperes
the problem is i want to make a filtered power...
Homework Statement
Ok, you'll have to bare with me on this problem, this topic is not covered as part of my second level education. I think that ye do this in the US though.
You are given a circuit containing a non-ideal power supply, an NTC resistor, an ammeter, a voltmeter, and a switch...
Is it unreasonable to buy or build a power supply circuit that is rated at 500V and 4Amps?
Thanks.
I know 500V is possible, but not at that high an amperage.
Anything in and around $5k would be fine.
Hey guys,
I have a question regarding connecting up 6 * 3mm/5mm super bright mcd Led's in parallel (since they would all have the same forward voltage when wired this way), using a supply voltage of 3V but not sure whether is should be 2*1.5V AAA or 2 * 1.5V AA batteries.
The reason i put...
I have a servo motor that I'm controlling with a simple PID controller for a constant frequency square wave with varying duty cycle. My supply voltage is 5.17V with ~1V drop across my low side driver. The controller sits right around 50% duty cycle to keep the servo open to position A. A...
I need a DC power supply for a project I'm working on.
I have a Leach amplifier with a monster power supply and heat sinks able to handle it clipping at ~500W/channel. It's just sitting on my floor.
I also have a 2 16bit 1MHz DACs and 2 16bit 200KHz ADCs attached to a National Instruments...
All,
Well, I have this idea for a patent ... but ... it requires a power supply ... and I can't find one that meets my needs.
I need to come up with the smallest, cheapest 110VAC -> 20VDC, 10AMP (or close to that) power converter (about 190 - 200 Watts), constant voltage.
Small means...
Hello, I'm new here and I apologize for my first post being a design question. I'm a 20 year old junior Electrical Engineering student from the University of Akron.
I need some help with a design that I can't get working for the life of me!
If you know pSpice Schematics, or OrCAD Capture...
I heard recently that Wheat (grain) production decreased due to drought in Australia and other areas, e.g. midwest US. Several countries have curtailed or reduced export and in some cases are now importing. At the same time, the cost of production has increased, in part due to increased energy...
Find v1 and v2 in the circuit shown. Also calculate i1 and i2 and the power dissipated in the 12-ohm and 40-ohm resistors:
My work so far:
i_1\,=\,\frac{N1\,-\,N2}{12\Omega}
i_2\,=\,\frac{N2\,-\,0}{40\Omega}
i_3\,=\,\frac{N1\,-\,N2}{6\Omega}
i_4\,=\,\frac{N2\,-\,0}{10\Omega}...
Alright, this may seem a bit of a childish question, but for my sake I need it answered. So please stay with me.
Alright, pretty much what this is all about is the effect that space exploration has on the Earth's air supply. We were all sitting around talking about the creation of a space...
i am stuck. i have no idea how to start on this project. I have to build a power supply that produces 5.0V regulated. i can't use regulators so i have to build it but i have no idea how to get started. i have an ac course to start with. i would appreciate any ideas, insights or designs you might...
I'm trying to find the size of pipes that are to carry a certain amount of heat in them, 6000 W. This formula should give me the amount of water needed:
m=W/(4200*delta T)
Delta T is 20 degrees (the diff between supply and return), but what I don't get is that if I increase the supply and...
I recently modified a computer power supply into a lab power supply. I would like to check the amperes bieng output, but where can I get an ammeter?
Or can i make one and how much does one cost.
Heres a link to a pic of my PSU
http://i106.photobucket.com/albums/m261/Squall_11/PSU002.jpg
I recently bought an nVidia 7600gt video card and I can't figure out if I am supposed to hook it up to the power supply or not. I have a friend that has the 6800xt and it does hook up to the PS. But nowhere in the manual does it say that this card should hook up to the PS.
Here is the card...
"Universal" laptop power supply?
My father had an extra laptop lying around that despite being old and having had it's monitor separate from it's chassis was in perfect working order. Or such was the case several months ago - I dusted it off today and it refused to start. I got out my...
I just bought a new 750W powersupply off of newegg and put it in my computer and tried to fire it up. The fans on the back of my computer spun for a fraction of a second then everything turned off. My monitor kept going from green light to orange light for some reason (even when I turned off the...
Need a little help here...getting started. I don't really understand what to use here.
If two 1000W toasters were to be connected in series to a dc power supply, what power supply voltage would be necessary for normal operation? Assume each toaster was designated to a 120V ac circuit...
I have an aptitude test in a Suppy chain management Company for the post of Software developer ( fresher).
What kind of questions should I expect?
Thanks !
Wow! An Electrical Engineering Forum! :!)
Please help!
I'm a newbie in the field, just got my degree last May (2005, BSEE). I focussed on computer engineering and can program the crap out of a micro-controller. Now I'm working on some automated test systems and have to work on a lot of...
I'm seriously lost!
Here's the problem:
It has been estimated that the Earth contains 1.0 x10^9 tons of natural uranium that can be mined economically. If all the world's energy needs (7.0 x10^12 J/s) were supplied by 235(U) fission, how long would this supply last? Assume that the average...
Dear All,
In talking about taking electrical equipment to Japan, we were wondering about the effect that the supply frequency might have on the output of the equipment’s power supply. We have tested it in the UK as far as we can.
The power supply, being powered at 100v through a...
Hi, this might not be electrical engineering, but I found no other forum to question about this.
I'm trying to get a 5V regulated power supply from a 12V, 300mA transformer. I can't seem to get it to work. I'm using a 5V regulator, two 470 microfarad capacitors and electronic wire in a...