Supply Definition and 515 Threads

  1. B

    Low Voltage AC Supply from Wall wart?

    Hi - I'm just starting to build a few basic circuits and am looking to get easy access to a low voltage ac power supply. I pulled apart a power brick, and it only has 4 diodes, a cap, and a transformer. If I pull out the cap and the diodes and solder the cord to the leads on the transformer, I...
  2. Hepth

    What Happens If a PC Power Supply is Maxed Out?

    I currently have a slim-line PC I bought real cheap. http://www.abcwarehouse.com/product_catalog/pc_proddetails.asp~prod_id~34788# I paid $200, not bad. Well, the case is Custom, as is the internal power supply. The video card is lacking, and I know there are quite a few pci-e...
  3. S

    Uninterrupted Power Supply (UPS)

    Hi, I have an ups used for my PC. I have just replaced his faulty battery and checked the output on battery operation with a multimeter.The reading are as follows: 1. Without load the ouput is about 184V. 2. With load the output is between 196V to206V. Can someone tell me if I use the ups...
  4. P

    Medical Why is the drug for lethal injection in short supply?

    It's reported that sodium thiopental, the first of the three-drug cocktail in lethal injections, has been in short supply across the US and the state of Oklahoma responded a few days ago by using a veterinarian drug instead. Some other states have suspended executions. Strangely, none of the...
  5. J

    Question on Evaluating a Power Supply

    I'm evaluating a wall-transformer type power supply used to power guitar effect pedals as a replacement for a 9V battery. It's rated at 9V and 2000 mA. I put resistive loads on it of (nominally) 16, 8 and 4.5 ohms, and made measurements with a Klein Tools MM1000 multi-meter. Here's what I...
  6. S

    Electrical Electron Accelerator/Decelerator grid supply

    Hello. I want to build an electron accelerator grid in vacuum. The grid, which has the purpose of accelerating or decelerating electrons produced by a nearby filament has to be electrically charged at +500V or -500V. The switching frequency between the voltages +500V to -500V has to be...
  7. C

    How can I eliminate AC leakage in my power supply for optimal performance?

    Im using the 7809 IC to get 9v regulated dc supply. However, I'm also getting about 14v ac in the output as well. I've tried putting a notch filter tuned to 60hz to remove the ac voltage, but its still there. I'm using this power supply to power tl072 op amps and I'm worried that the ac voltage...
  8. S

    What happens when a power supply is has more volts but less amps than you need?

    Hi guys and gals, please forgive the lame-o title, first poster here! I recently picked up a pretty fierce interest in electronics and I've been doing plenty of reading and experimentation but I have a few questions that I'm hoping will land on generous ears. What follows is a "brain dump"...
  9. M

    Set Up Dual Line Bench Power Supply For Op Amp Testing

    This is a very silly question. I can't believe I have forgotten. I have a 30v bench power supply and I am looking to test an op-amp running at +/- 15v. I have a supply which has a negative output/ positive output and inbetween a green common/earth output. How do I wire them to produce the +/-...
  10. B

    Op-amp supply voltages wrong way round.

    Hi I'm somewhat new at this practical electronics stuff. So could use some help. I'm trying to debug a circuit made by a colleague who has moved on. It's a derivative of a non-inverting amplifier designed to amplify a signal from a generator. It works, to an extent, however the output...
  11. L

    Op amp output when supply is missing

    What is the output of the op amp when either Vcc or Vee is not connected. I simulated this and got Vsat. +Vsat when Vee was missing and -Vsat when Vcc was missing. But I don't know why the output saturates to +Vsat, even in a inverting configuration. Shouldn't it go to ground, since the...
  12. D

    Need help interpretting OpAmp spec, supply voltage

    In the datasheet it says the voltage max is +/-18V. Does this mean that the maximum on Vs+ is 18V, or that the maximum voltage between Vs+ and Vs- can be 18V, or 36V? I want to power it with Vs+ at 36V and Vs- at 0 volts.The datasheet is here: http://focus.ti.com/lit/ds/symlink/opa627.pdf
  13. A

    Designing an Auto Match Unit for RF supply

    I've picked up a 13.56 MHz RF generator from eBay which I plan to use for an ICP plasma project (this is what it was designed for). I need to construct an RF coil and parallel capacitor with a resonant frequency of 13.56 MHz but I also need to construct an AMU as, as I understand it, as soon...
  14. D

    Calculating CFM from 800 PSI Air Supply

    If I have an unlimited air supply with 800 PSI and fed through a 1' pipe how do I calculate the CFM
  15. U

    How Can I Adjust Vcc to Correct a 10V Output on my Amp Power Supply?

    Hi, I'm trying to understand how to correct when you put Vcc as 10V your max output is like 9.18V. Is there a factor on the data sheet or what? I'm trying to build a bi-state multivibrator to generate a 10V peak value but it's being saturated. thanks.
  16. D

    Three phase induction generator on a single phase supply

    Hi, I’m really stuck on a problem for my final year project in my taught Masters degree and any suggestions what might be going wrong would be greatly appreciated. I’m trying to run a three phase delta connected induction generator on a single phase supply using a Steinmetz connection. The...
  17. G

    How to operate a 3-ph, 440V equipment using 1-ph, 230V supply?

    As the title states, I've been having trouble figuring out how to run a certain large dryer for corn and rice due to the available supply in our locality. The dryer is a modular equipment that runs at a total of 30-hp and requires a 440V, 3-phase supply. The only available supply is 230V...
  18. D

    Why use high frequency power supply for generating plasma?

    Why use high frequency power supply for generating plasma?? Hi everyone, I noticed that for the plasma ball common in science museum, power with high frequency should be used for generating so called plasma inside to give out colorful glow. But one thing I can't understand is why power supply...
  19. A

    Solving the Problem of Unwanted Mains Supply Field in a Faraday Box

    Hello, I have constructed a Faraday box with alluminium sheets having holes on them. The problem is that the mains supply field is not canceled within this box. The box is about 50cmx50cm and hosts a number of electrodes and an electrical drive that moves these system of electrodes. I...
  20. R

    Infinite supply of marbles probability problem

    Homework Statement A has an infinite supply of marbles numbered 1,2,3,... A places the marbles, two at a time and in numerical order, into an urn (i.e. first 1 and 2, then 3 and 4, etc.). Each time A puts two marbles, B reaches in and pulls on out. This process goes on forever. c) If B...
  21. N

    Can an increased oxygen supply make you stronger?

    Hello, A friend of mine told me her dad used to work in the coal mines, like 800m under the ground, and he found that whenever he had to carry something heavy from inside to outside of the coal mine, he always noticed that carrying that same thing underground was easier than carrying it...
  22. H

    Changing Frequency of AC Power Supply: Circuitry vs Generation

    Can anyone tell me what the most standard way of changing the frequency of an AC power supply is? Can it be done with circuitry or does the method of generation need to be set at the desired frequency?
  23. W

    Building High Voltage Supplies for Amateurs: Safety and Considerations

    High voltage supply questions! :) Ok, well a few friends of mine have come together to build a fuser and an electron accelerator. I have obtained an NST at 20ma 6 kv DC , but would like to build a crockcroft walton voltage multiplier for the accelerator. My question is, will this setup run off...
  24. T

    Capacitor/Transformer Voltage Rating for a 12V Power Supply?

    Hello, About me...so you know where I am coming from. If you don't want to read, skip to the end-ish... I'd like to start off my saying that I know next to nothing about electronics although I am eagerly reading the All New Electronics Self-Teaching Guide right now and it is confusing but...
  25. R

    Choosing the Right Power Supply for Your M-Audio Keystation 61es MIDI Keyboard

    I need a power supply for my M-Audio Keystation 61es MIDI keyboard, and I think I might have one that will work for it. The user manual for the keyboard says this: But then their website is selling a 9v 500mA as the proper replacement...
  26. T

    Creating a simple DC power supply.

    Homework Statement In one of my labs for a circuit analysis class we are told to design a simple DC power supply. The power supply will have three outputs, +4.5V, -4.5V, and an adjustable output from 0-11V. I have already done most of this and the question I have is could you design this so...
  27. H

    Will this power supply work for my device?

    Will this power supply work for my device? URGENT! I have a Mini-fridge I need to get usable again. Recently, as of a few minutes ago, I opened up its power adapter to find that capacitors have burst and that would be the reason of the fridges death a few months ago. Given the mini-fridge is...
  28. S

    Why do nerves get a blood supply?

    Hello everyone, I like to know why nerves get a blood supply. Is it because they need ATP to open protein channel to carry out action potential, or is the extra cellular matrix of a neuron determined by the blood supply. If a neuron can not carry out cellular respiration, why would it cause...
  29. L

    How to supply Serial Clock Input into an audio-ADC IC?

    Hi seniors, I am struggling something with my audio ADC. I bought AD7811 from farnell, which is an ADC to convert my analog data into digital. But at this stage, i found that a SERIAL CLOCK INPUT is needed to supply into the IC. However, I m wondering what exactly the clock i should...
  30. D

    Why Ferrite Bead in Supply line

    Presently Am try to design a USB to UART,485& 232 board, in that Am using FTDI USB to UART converter, In the FTDI data sheet they providing some sample design and A ferrite bead is connected in series with the USB power supply to reduce EMI noise from the FT232R and associated circuitry being...
  31. D

    3-Phase Voltage Supply Simulator

    In the study of power electronics, many tertiary education institutions faced problem in setting up an electrical lab where experiments are conducted using three-phase voltage supply. The difficulty arise was mainly owing to student safety factor. Also, the costs for such experiments are...
  32. F

    What Factors Affect the City Water Supply Pressure for Plumbing Design?

    In plumbing we need to know the pressure in the city main supply , my question is how can the city give us the minimum pressure of its supply for our building let's say before pluging in our whole plumbing system to the city main line ? usually the pressure at a node is determined when it...
  33. M

    Clipping and V supply and Voltage at collector of a transistor

    Hi, I am new here, I'm still in high school here in Melbourne Australia, so please excuse my stupidity. Theres a question come up on a massive project that has a large bearing on our end of year results, its got to do with clipping of an output signal, and relating it to the Supply voltage...
  34. J

    Electronic Supply sites make me cry (A switch-related question)

    Electronic Supply sites make me cry :( (A switch-related question) Ok so I've been going through Newark's site, trying my darnedest to find a tactile switch that A: does what I want, and B: has plastic switch caps of some kind that fit. To address item A, I need a tactile button that is...
  35. E

    A simple non latching,I.R.switch to supply 90 ma .

    I have made an onboard uncoupling device for my model railway,It works perfectly using the circuit from a toy helicopter.Can anyone suggest a suitable circuit to make myself? I wish to use a 3.7v battery and the device uses a coil drawing 90 mA for 3 seconds from 1-2 metres range.
  36. N

    Design an OP AMP Power Supply for Audio Preamp

    Hello, I am trying to design a foundation for an audio preamp that is powered by a single 9V battery. I am successful so far except the single power supply part. I am using the voltage divider scheme to get a +4.5V and a -4.5V reference voltages. With no load the supply voltages are close to...
  37. M

    LC Circuit with DC power supply

    A circuit has a battery(V), Capacitor(C) and Inductor(L) connected in series. At t < 0, the switch is open and the capacitor has an initial charge of -800uC and Io = 0.0Amps.. When the switch is closed at t = 0, I want to know what happens here. I only understand an LC circuit where there is...
  38. F

    Three Phase A.C Supply: Explained

    i was reading three phase ac supply and this statement is quite confusing ''because of the 120 degrees phase shift the voltage across any two lines is 400 volts (the voltage across each of the lines connected to the terminals is 230 volts) can anybody please explain it??
  39. S

    HELP 3 phase supply keeps interchanging

    PLZ HELP!3 phase supply keeps interchanging Hey friends, The power supplying company at my place keeps changing the phases on daily basis and this has caused a nuisance.. In my country the colour coding is "Red-Yellow-Blue" I have to change the Main supply wired to "Blue-Yellow-Red"...
  40. L

    Switchmode power supply question

    Why are SMPS smaller than linear power supplies? I understand when you switch at high frequency, the transformer,inductor and capacitor size reduces. Usually, there are 2 transformers in a smps. One at the AC input and one after switching. How do they rectify the 60Hz using the first...
  41. J

    Power Supply for EE Student Experiments at Home

    I am an EE student and would like to get my own power supply so I can experiment at home. I saw these two power supplies at frys and was wondering if they are any good. One is 0-30V 0-3A and the other is 0-60v 0-1.5A. I would like to experiment with making audio amplifiers. Which one of these...
  42. V

    Power supply - Importance of amp Rating?

    Power supply -- Importance of amp Rating?? Hello all: I have a TV tuner that requires a DC 7.5 volt, 500 ma power supply. I have a 110 V input power supply rated at 7.5 V DC 1,000 ma. Can I safely use this powersupply with the tuner. Analogy: I can plug a 3.5 am vacuum cleaner into a 15...
  43. A

    Power Supply Alternatives for an Electromagnet

    Homework Statement For an electromagnet that is just made up of wires and a core, what power supply can I use other than batteries that let me adjust the volts? Can you explian in detail? Homework Equations none The Attempt at a Solution I have already looked on the...
  44. A

    Replacing a Wall Wart Power Supply

    Assuming I have the same voltage, correct polarity, and sufficient current, can I generally replace any class 2 power supply with any other? This will be used for common household electronics. In particular, when researching power supplies, I see specifications for ripple, noise, setup, rise...
  45. T

    Laptop Power Supply: How to Charge Battery Externally

    Greetings, Does anyone know how to use a laptop's charger to externally charge its battery? I am using a battery from an old DELL laptop to power my handheld radio. I wish to use the charger that came with the computer to rejuvenate the battery, however, the charger circuitry is smarter...
  46. G

    What is the Optimal Change Strategy for a Baker?

    Does anyone know results about how much and which bank notes a baker should have at the beginning of the day, to insure we will always be able to give proper change to customers? Maybe the question could be: Basically given a distribution of bank notes of the customers, what is the...
  47. S

    Power supply input discharge voltage

    I would appreciate any help, opinions or explanations on this as I am receiveing many different views currently. I measure the discharge voltage of a single power supply (laptop ac charger) using a digital chart recorder. On a trial and error basis I achieve the data as close as possible to...
  48. S

    Effect of variation of steam supply

    Hi, I am doing my revision and one of the question got me thinking but I am not sure if I got it right. The question asks what is the effect of variation of steam supply on power output,power factor,armature current and load angle of the synchronous machine. I think reduced in steam...
  49. N

    Design Pump w/ 158m & 250m Water Levels

    how to design a pump with top water level at the intake is 158m and to the treatment plant of 250m top water level
  50. N

    Design of a water supply system

    how to identify water demand in an area
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