Power supply Definition and 301 Threads

Hello, Certain power supplies can be both a voltage source or a current source. a) Voltage source: We set the voltage to a specific value we like and change load resistor. The current will vary (get smaller for larger R) but the voltage will not vary. To make the power supply a voltage source, I...

I am working on a switch mode psu in step down configuration with the key components being: LM2592 (adj) http://www.ti.com/lit/ds/symlink/lm2592hv.pdf 530-PC-24-1000 http://www.mouser.com/ds/2/643/PC-594199.pdf GSIB-25 http://www.vishay.com/docs/88646/gsib25xx.pdf Using a slightly modified...

Picture for reference is below. I'm confused as to how this is able to receive a differential voltage of +/- from a single power supply. (Yes, I know the picture says dual power supply.) Normally I have to short the negative to ground on one side of a dual power supply, and short the positive...

Homework Statement So, for a school project I have to make a resistance soldering iron. As far as I know, this requires a high current going through high resistance wire (such as stainless steel in my case). I need to make this run from a standard 120v 15A wall outlet. I have figured out so far...

Trying to build a simple 9V power supply using a 7809 voltage regulator and full wave rectifier. The load current from the regulator is 1A. So I = C*dv/dt, therefore, C = I*t/(delta V) To my understanding t is the time between the two peaks or the time the capacitor supplies the load. So if...

Will my described method allow me to achieve my objective? If so, could you recommend a rheostat that is rated for at least 20A @120VAC that will work for my application? If not, could you describe an alternate method? Objective: Determine the ampacity of various wires at 120VAC Method: Wire a...

Wanting to know if it is possible to power a LED with a forward voltage of 29.3V and forward current of 440ma from a 1.5V source with a 2400mAh Capacity? No particular need for this, more for challenge/knowledge. Have tried methods with a transformer, DC-DC converter, and lm350 constant...

I have a ton of 3.7 volt lipo's at my house, each of which can be charged @ 5C, and since each have a capacity of 270 mAH, than I should easily be able to charge them @ 1amp. I put 8 in parralel with each other so it is a 1s, 8p battery pack. each of the lipos is the same (in tems of specs, ik...

Hi all, I've just watched a video about the problems of back-feeding your home with an inverter/battery source, most of which relate to the split-phase system in the US. It got me thinking about the differences between this and the UK (and EU) mains supply, which is single-phase 230V. This...

multiple 220V to 5v, 2A ac to dc adapters connected to the same 2-phase input terminals input voltage is 220v domestic supply. is it safe to i join output in series to obtain 10v /15v/25v etc. ?

suppose there was no ground stick at power generating station . then there would be no reason for a person to get an electric shock. no need for ground wires. only live and neutral wire for domestic supply. why is the neutral wire connected to Earth at generating station

Homework Statement So the circuit drawing is in this link http://i.imgur.com/jVYm5La.jpg . Basically, we have to create a power supply circuit and using Livewire and PCB wizard program in conjunction, I created this circuit Homework Equations None? The Attempt at a Solution [/B] I can't...

I designed one transformerless power supply and did lots of calculations for that. can anyone answer me how to calculate value of capacitor using as a smoothing capacitor parallel to zener.and also tell me if the value of capacitor is larger than required then what changes may occur in the...

Hello, I'm an Aquaculture Engineering student at lima. I'm trying to do an experiment of electrochemical harvesting of microalgae. But it seems my weakness at physics its getting in the way plus i don't know to well how to operate the equipment which none knows either since its new to the lab. I...

So many moons ago I made myself a pretty bog standard dual linear bench power supply using an LM317 and LM337 to give me -15 - 0 - +15. In an attempt to get more current out of it (for no real reason other than because I can) I got a larger transformer and a beefier rectifier, then using the...

Homework Statement Specify ratings and values for the transformer, bridge rectifier and smoothing capacitor for a 230 V unregulated power supply with an output voltage of 12 V, output current of 2 A and a ripple factor of <0.024 Homework Equations V * I V*sqrt 2 C= I/2f*Vr Id=(1+sqrt2)*ILThe...

Hi guys, Here is the amp schematic, http://www.classictubeamps.com/schematics/Marshall/1966%20JTM45.pdf Here is the power supply schematic I would like to modify and use. http://imgur.com/a/sdYAV I don't know how to get both of these schematics to display in this post...I guess I will never...

I'm pretty darn new to engineering, so I'm just diving in and hoping all goes well. I've got roughly 6 months to finish this project as it's a Christmas gift in the making. My current plan is to carve a large spruce log into the shape of an old cathedral style antique radio, make a cabinet...

I recently salvaged a Melles-Griot HeNe laser from an FTIR system. I neglected to save any of the electronics except for what I think is the step-up transformer attached to the laser tube. The laser is "05-LSC-708-540" and the transformer is "05-LPM-850-045". I have a 12V power supply, but was...

What is the voltage leaving the rectifier? What is the voltage at the two 22 ohm resistors? What is the effect of the 4.7 volt zener diode?

Homework Statement When the internal resistance is large in comparison to the external resistance, the terminal potential difference falls to a small value. This is used to make high voltage supplies safe for use in a laboratory. Explain how this makes the supply safe. Homework Equations...

Hi! I'm trying to build a variable voltage DC regulated power supply that is 0-30v and 2mA-3A. The problem I'm having is that as soon as I plug it into get a reading on my multimeter it reads 34v, even if I try turning the pot it does not change. I've rewired the pots and made sure the...

It is safe to add on extra socket by this way? Original connection: postimg.org/image/v6nshoygh/ Add-on connection: postimg.org/image/vkoccsyu5/ The extra socket is for light usage only. Water heater is instant water heater without tank. The switch is double pole single switch.

Ok folks, I haven't got much answers lately here and almost none with my last smps ground wire thing but here is another problem I'm facing , on the outputs (DC) from my smps after the bridge rectifier diodes and a smoothing filter cap bank I still get about 1V or bit more parasitics which I am...

Hi Guys, I want a to buy a DC power supply to experiment with to power transistor amps that I want to build. I also I want to power up 12V car radios and other low voltage devices. I am looking at this one new from ebay which cost about $50.00. " 30V 5A Precision Variable Adjustable Digital DC...

I am looking into different methods of power supply's when I found out about switch mode power supply's. These are the type of supply's that you have in your phone charger (or at least i believe so). The type of supply I need, is something that can supply a voltage of 2.5 volts @ 70 amps, and...

I have an old motorcycle which I would like to fit with a modern CDI ignition. The ignition would be of the type typically fitted to dirt bikes and which require a high voltage AC source. They have a permanent magnet alternator with a separate high voltage stator for the ignition in addition...

Can a supercapacitor be a power supply?

I recently bought a DC power supply online to perform experiments that require electricity. I am not an expert with electricity so I have a few questions about it. It has a maximum of 10 amps and 30 volts, and both values are variable, however it does not show me the value of the current unless...

Hello community, I am building a device for which I will be using five Stepper motors (each 5v, 3a) and one brushed DC motor whose speed has to be varied and operates between 12V and 48V (350Watts). Also I have a heater which runs at 12V, 40Watts. My question is: How will I best power these...

Homework Statement a 12v dc supply is connected across 2 100k resistors in series.a voltmeter having sensitivity of 10,000 ohms per volt is switched to its 10v range and is connected to its 10v range and is connected to measure the voltage of 1 resistor. Homework Equations 1)sketch circuit...

Hi, When the modern 80 plus power supplies are quoted as being "87% efficient" on 100% load, does this mean that an 80 plus Gold PSU rated at for example 1000 Watts will provide 1000 Watts to the internal PC components, and therefore draw 1000/(0.87) = 1149.43 W from the wall? OR does it mean...

1. Homework Statement Homework EquationsThe Attempt at a Solution My answer to (b) was that power supply would have an internal resistance which is not negligible and will affect results. The correct answer is that shorted lamp A would cause damage to the lamps/supply. How is lamp A...

I just recently finished a new computer build for $280, or so I thought. I did it reluctantly. I was hoping to hold on to my old Core2Duo I built back in 2007 until 2022 when they stopped supporting Windows 8. In fact, I probably would have pushed it even until they stopped supporting Windows...

Hi folks. I'm currently designing a 4000w LED chip array in which I plan on using 3x 1500w 12v switch mode power supply's. A DC-DC converter will convert the 12v to 35v powering two chips. This totals to 20 step up converters and 3 switch mode power supplies to drive the proposed 40 100w chips...

I'm sorry if this isn't the right place for a shopping question, but I'm not sure where else to go for advice. I got a https://www.amazon.com/dp/B0094KM4VK/?tag=pfamazon01-20 on sale and the unit is great, but the batteries don't hold a charge very well, especially when using rechargeables - it...

Hi I know little about this but I am wanting to wire up my 1mw green laser to my usb port to use it as a power supply it is 3 volts I'm wondering is there a program you can use to change the 5 volt output to 3 volts or would I need to use a resister in the wiring ?

I have a thing I want to build(scanning electron microscope) that requires like 5-10 different power supplies within the 1-20 kv range. Instead of building all of them, can't I build one 250kv power supply and split its power into all of these different high voltage components? How would you...

my 3inch plasma globe needs 5V 300mA dc supply... Can I use an adapter with 4.5V and 50mA output rating? If can't then what will happen if I still do use it?

Hello, I'm planning to light up a tile chess board with 64 LEDs (blue and white) set between the tile squares, and I was wondering if this Class 2 Battery charger output: 12VDC 900mA, would work to power 16 parallel sets of 4 LEDs + 1 ohm 1/8W resistor and a SPST toggle switch? The current...

Hello all. If I was to create a circuit with a 2 kV power supply, how would I reduce the current so that if I were to accidentally become part of the circuit, I would be in no danger? Another question: Does a bleeder resistor help? Thanks.

I'm looking to build a varied, high frequency power supply for a strobe light. Any suggestions on the best way to go about this? I would prefer to have it computer controlled so that I can change the frequency without manual input. Any pointers would be really appreciated! Thanks!

I'm trying to re-purpose an old Compaq (and another HP) ATX computer power supply to use as a lab PS. I've seen tons of articles on line about how to do this, for example. I can't get it to even start up though. I have the power-on pin from the ATX connector that goes to the motherboard shorted...

Hi. I have made a 12Vdc 3A unregulated power supply for my projects. I want to do some electrodeposition, and the 12V are a bit too high (It starts to electrolyze water and the deposited copper breaks very easily). I'm looking for a way to step-down the voltage without using too much money...

Hi. I'm joining this forum to ask about some equipment I need. At the community college where I teach, we do a lab in freshman physics where students measure the input to and output from a transformer. My AC sources are reaching the end of their lives, so I'm looking for replacements. As far...

Homework Statement I have recently learned about the boost SMPS and and have built a circuit to investigate the waveforms and levels for Vout, [L] and [C] for different mark space ratios. the circuit consists of a 95uH inducotr, diode, 47uF cap, 70 Ohm load, a FET who's gate is controlled...

Hi! I want to design DC power supply 12V 2A. Here is what I have done. Firstly, we need to transform AC main voltage. I will use transformer with ratio Np:Ns=16:1 : We must choose diodes with maximum forward current more than 2 amperes. I will choose UG8JTHE3/45.. This diode has maximum...

I've built a small voltage regulator that I can use with my breadboard or to test circuits. It is the first circuit that I've actually soldered together, so please disregard the hack job. The problem with the circuit is that when I hook up a very small load to the supply, the voltage plummets. A...

Hi all! This is my first post here and I really hope you guys can help! I am currently in senior design at Purdue Fort Wayne in the MET department. I also own a company called Graphite Customs where we make graphite molds for glass blowers. When machining graphite, the powder is very abrasive...

I have a power brick (transformer) that sends 12V, 17.9A to a device. I have another device that requires 12V, 10.83A. If I put a 1.7 ohm resistor in parallel to draw some of the current: \frac{12V}{17.90A-10.83A}=1.697312 Could I use it to power the 10.83A device? I'm just not sure if it is...