Power supply Definition and 301 Threads

Since we want the current to stay constant, the change in potential energy that's caused by the coil flipping in the magnetic field should be "undone" by the work done by the power supply, so shouldn't ##W = -\Delta U## ? the answer guide did it without the negative sign, so I'm wondering if the...

I want to buy a car/motorcycle battery charger because it's a very convenient thing to have. Also, for a while, I have wanted to have a simple power source like shown. How safe is it to use it to charge lead-acid batteries from cars or motorcycles? I know the simplest option is to buy the...

Hi, I've ordered and received an advanced heat pump from Jiangsu Micoe in Red China. It is a full inverter-driven air-to-Water heat pump, IOW the fan motor, compressor, etc, are all PWM driven. The power supply takes in line voltage and immediately converts it to DC for moderation by the...

I have a CCTV camera using the ordinary 12 volts AC to DC adaptor that has higher voltage (like 15 volt) when there is no load. I decided to buy a Meanwell adaptor but the datasheet (below) I got doesn't give the no load voltage. What do you call power adaptor in which the voltage is higher at...

Good afternoon, How should an upstream isolation transformer be sized for a dc power supply? For example, if we have a power supply with the following specs: Input Voltage: 120 VAC Input Current: 2 Amps Inrush Current: 22 Amps Efficiency: 90% Power Factor: 0.55 Output Voltage: 24 VDC Output...

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 been trying to build a simple Current control circuit using a NPN TIP35C transistor but have run into the problem of it constantly over heating and being destroyed. The transistor is the only component that heats up whilst it is on. The supply voltage is 10V, well below the Max and at the...

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...

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...

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.

Into a project I am working is use 12Vdc SMPS to power an audio amplifier and some more components. We have no “noise” on that stage. Then I use a step down converter to convert the 12V to 5V and power a mic preamplifier (Respeaker – usb Mic array) and a development board. There is a lot of...

I know that the answer for A is 31.82. But when i look up B why is it zero? can someone explain please thank you

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?

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...

My dad has been asking about some speakers for his boat, something that will move a bit of air, not too big though. I'm thinking 1x12. He also wants it bluetooth and powered externally, so it doesn't drain the boat battery. So I'm thinking 1x12 speaker in a small box that can fit inside the...

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 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...

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...

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...

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...

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...

Let's say you have a UPS 550 Watts (1100 VA). How much current or watts does the unit itself used? This is important when your source itself is limited by the wiring.. let's say all your computers total 500 Watts and the wiring is sized for roughly that.. Would the UPS draw more current or...

Interesting article sent out by Digikey just now...

Is there some common parameter for DC power supplies that provides the maximum oscillation amplitude allowable at the output? For some context - I would like to generate an oscillating signal powered by a DC power supply, but to prevent most of the oscillations reaching the DC supply I am going...

I have a 30V 5A variable linear power supply, which has failed twice from transients killing the LM358 quad op-amp IC that controls the output. These transients are from driving things like a car ignition coil, for making an electric fence energiser. Simply replacing the LM358 gets it going...

I am searching for a legible schematic diagram for a Tenma 705-72 DC laboratory power supply. Each of its two channels uses a LM723 regulator and a pair of 2N3055 power transistors. One of the channels operates normally; the second channel puts out the maximum voltage (37 volts). Any help...

I am struggling to understand the voltages present in the circuit below. So as stated in the diagram, there is 30V AC at the secondary of the transformer, this is equivalent of 42.4Vpeak. The bridge rectifier changes this to DC and drops the voltage down to roughly 26.3Vpeak DC where each diode...

building a DC supply with a load voltage of 3.3V and load current of 3.3mA. all the books and schematics I'm seeing is that they're putting the fuse in the primary of the transformer, why? if i were to fuse the primary as well how do i get the rating of the fuse that i'll need? its said in my...

Homework Statement Design, giving the necessary ratings and characteristics necessary for the transformer, bridge rectifier, reservoir capacitor and regulator, a 12 V, 2 A regulated power supply. Also identify any heat sink requirements. The available mains supply is 230 V ±10% @ 50 Hz...

First off I'm not an engineer nor do I have a electronics background. I have an old Linear (HP 6284A Power Supply). I would like to be able to display Hz/CPS. I need to measure the speed of a tattoo machine. (basically two coils that make and break connection through out its use. From what...

Lavolta BPS 305 0-30V and 0-5A. I was showing a young lad how you can energise a car ignition coil and get a spark on the output, and that this effect can be improved by adding a cap in parallel which forms a crude LC oscillator etc when the unit died. Silly, I know, but we got a bit carried...

what is actually happening when an Inductor is connected with an ac source.(i mean at the very instant of connection is made).i know emf will be induced due to change in current.(curl of E is =-time derivative of B)here my confusion is,inorder to induce emf,current should flow first,then who...

I've got an old laptop charger 19v 3A for my solenoid. I used a multimeter to check the charger without and with load. I used a solenoid of insulated 22gauge of approx 150 turns as the load. On my first try without any load, it gave 20v DC on the multimeter. When I connected the load and...

Hi, Out of interest, today I was mucking around with a 160W LED, 240V, 50hz, outdoor light. I looked at the Power Factor (it was 0.96) and the THD was 14.something %. I then wondered what would happen if I put a capacitor in parallel with the light. It was a three phase 90uF cap, so since they...

For a project,we thought of making solenoid engine. We made everythig by hand, including the DC power supply. The power supply worked very well, it's puts out like 20v 1A, and it was fine still after testing it for a long time connected to DC motor. When we connected it to a solenoid coil...

Hi, For my project I am plotting a Force vs Displacement graph using 2 analog inputs which are going to a DAQ. The two analog inputs are coming from; -A 5k potentiometer (for the displacement) -A 1000 lb load cell sensor (for the force) I would like to use a regulated 12V DC (1Amp) power...

In this project, I am using the https://www.amazon.com/dp/B005W09XYW/?tag=pfamazon01-20 as a power supply, but in my project, if my device shuts off suddenly without shutting off properly, it would require me to reboot the entire system as it won't work anymore. So I decided to use this power...