Questions tagged [high-current]

Say how much current is required, high-current means different things to different people.

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29
votes
6answers
5k views

How can the contact points of jumper cables handle the hundreds of amps required to start a car?

When jumpstarting a car, you connect those big alligator clamps to the terminals of the batteries. The cables themselves can handle the current just fine, but the contact points between the alligator ...
25
votes
5answers
16k views

High PCB copper thickness: What are the pitfalls?

We need to carry high currents on a PCB (~30Amps sustained), so we are likely to order our PCBs with high copper thickness. So far we've only used 35 microns in our designs, so 'high thickness' for us ...
24
votes
7answers
36k views

How to carry high current on PCB

I need to pass high current on some part of my circuit. I used an online PCB track width calculator to see that required track width is about 5mm and minimum clearance is 1mm, which makes it about 7mm ...
22
votes
14answers
4k views

Finding a faulty chip that draws too much current

Note that this is a theoretical question - there is no schematic I can show. I will show some schematic, but it will be a very simplified version of an actual circuit, only for illustration purposes. ...
21
votes
7answers
4k views

Is there a downside to using multiple relays simultaneously to increase relay capacity

I want to install a relay to my fusebox which is controlling whole basement with machinery. Relays that I have have got 2A limit each, and I have 32 relays. Can I just use all of them for the same ...
16
votes
3answers
5k views

How many MOSFETs can we safely parallel in condition of very high currents? I had problems with a motor application at 48V 1600A

I tried with some configurations in which 16+16 MOSfets of 240A each (really they are case limited to 80-90A because of source terminal, but i doubled this termminal with a very thick copper wire for ...
13
votes
1answer
833 views

Safety when experimenting with large currents

I am experimenting with large currents from ultra capacitor discharge. For example with 500 A (at 2.8 V) you get a very impressive demonstration of the magnetic field of a straight conductor using ...
11
votes
5answers
5k views

High Voltage PWM Motor Controller - Mosfets Explode

I've searched every post for an answer to this problem. I've built a motor controller circuit as shown in this diagram. I made the diagram as accurate as possible. The diodes on the mosfets were ...
11
votes
5answers
4k views

Automotive ground shift phenomenon

I'm working on the integration of a sensor into an automotive platform, using a standard 12v negative chassis setup. I am trying to understand a somewhat mythical phenomenon that is experienced known ...
11
votes
7answers
2k views

How can the ACS712 pin handle 20 A?

I am searching for some current measuring ICs and found the ACS712, but what I can't figure out is how the seemingly small pins can handle the 20 A current since the trace width calculators say that I ...
9
votes
4answers
8k views

Controlling high current (1000A) with MOSFETs

I am currently designing a capacitive discharge spot welder and am running into the issue of switching. I plan to use a few super capacitors in series to discharge around 1000A in a very short ...
9
votes
3answers
2k views

PCB layout for high side switch (high current)

I'm working on a PCB layout for two high side switches. You can see below a picture of my current layout. The copper weight of the future PCB will probably be 2 oz/ft² (double sided). I use two p-...
8
votes
5answers
1k views

Best way to test a high current pcb design 70A @ 12V

I designed a circuit (MOSFET HBRIDGE) that Should Be able to handle 70A @ 14V. Now that the board is sent out I am on to thinking about how to properly test it. Right now the most logical way I have ...
7
votes
2answers
11k views

Creating a high-current bus on a PCB

I'm planning a custom power-distribution / fuse-board for in-car application, but that requires carrying high currents (50A+ @12v*) on a PCB trace. Since I'd like to keep the board cost, and physical ...
7
votes
1answer
813 views

Series pass transistor, LM7812

I am making a 12 volt regulator for a solar panel to power an audio amplifier. I already have a switching regulator for most application but it is very noisy for amplifier even with a lot of filtering....
7
votes
2answers
4k views

Alternatives to breadboards for high-current applications

I've read that solderless breadboards cannot handle more than 1 A of current or so. What kinds of alternatives exist to a solderless breadboard? Would a soldered board make a difference if I want to ...
7
votes
2answers
893 views

Can I build a high-frequency SMPS choke out of an arbitrary coil of wire?

Suppose I want to build a boost converter that runs at 100 kHz, with an input voltage of 600VDC and an input current of 100 amps. (This is hypothetical, I know the semiconductors involved would be ...
6
votes
4answers
9k views

Square Wave input into Transformer

Can a square wave generated using an astable NE555 be used as input of a transformer instead of AC? Say, I generate a square wave of 60Hz using NE555 and a 24V at 6A supply and feed it into a ...
6
votes
1answer
268 views

Switch high voltage with triggered spark gap

I want to switch a high current/voltage pulse (up to few 10kV, <1kA) from a capacitor as supply. It needs to be cheap and I don't care about efficiency too much yet. I took a look at using ...
6
votes
5answers
1k views

The path of electrons in AC circuit?

I have a question regarding the AC circuit shown below. If we ignore the voltage drop caused by the long cable, I think the device will work and the circuit can be considered as a closed circuit. Now ...
5
votes
9answers
18k views

Switch capable of very high current?

I need to design a circuit that can turn a DC motor on and off. The motor is like a winch motor on a truck an can draw high amounts of current, in some cases up to 200Amps. The motor runs at standard ...
5
votes
3answers
17k views

Question regarding use of low voltage high current outputs

I see every day high voltage, high current; high voltage, low current. I rarely see low voltage, high current; why? I know that I can take a high voltage, high current signal, send it through a step-...
5
votes
3answers
7k views

MOSFET as Variable Resistor in High Amp Circuit

I'm trying to create a variable wattage heater circuit as shown below. I'm clearly not a trained electrical engineer (simply a hobbyist) so please forgive my crazy idea and general stupidity. You ...
5
votes
1answer
2k views

How to measure car battery current precisely in wide range (starter current, charging)

I want to measure car battery currents in high resolution and in wide range and both directions (including engine start and charging currents). I don't need very high precision measurement, but I ...
5
votes
2answers
1k views

Is there a standard way to implement desat protection on high-current FETs?

To implement desaturation protection on a switching transistor, one typically sets some manner of comparator to watch the voltage across the current flow terminals of the device. If that voltage ...
5
votes
3answers
16k views

is there some sort of paste, grease, spray or similar thing that helps make more contact surface for high-current battery?

I have terminals attached to a battery, which will conduct high-current (40A to 200A), and these are copper plates. As the plates, and battery terminals are not perfectly even (even if they appear to),...
4
votes
3answers
688 views

Why do they place a high current device in a low current package?

For instance, it is said that the practical current limit of the TO-220 device is 75A. But I frequently see MOSFET devices for which the specified maximum continuous drain current is above 75A. (...
4
votes
2answers
658 views

Protoboard components being used for applications with high current

If I have a few pins of a relay (which is rated for the correct current) that will carry 5A when the relay is triggered, what's the best way to wire this up? Details: I have a breadboard with a ...
4
votes
2answers
5k views

Can we remove the neutral wire?

If we have the connection shown below (star connection of the secondary part of a TX), the load per each phase is equivalent (balanced load), then the vector sum of ...
4
votes
2answers
1k views

Driving 3 LEDs at 1000mA. Is this circuit / driver ok?

I want to drive 3 LEDs in Series at constant current of approx 900mA - 1000mA. Will this circuit work? The LEDs are Vf 3.55V @ 1000mA. LED Diagram R1 = 0.25W 100k Ohm Resistor R2 = 2W 0.47 Ohm ...
4
votes
3answers
3k views

Dupont connector for 5A

I have to do a connector adapter, that has to handle 5A current, from a pwm motor driving circuit(power mosfet), to the motor. I have not found the current rating for dupont connectors It is ...
4
votes
2answers
7k views

How do current ratings on barrel connectors work?

I'm trying to power a pcb using a psu that is rated at 12V 10A and has a barrel connector with a jack that is 2.5mm x 5.5mm. I've tested my board with screw terminals and it draws about 8A. I want to ...
4
votes
2answers
677 views

Is it safe to use narrow but short PCB traces for high current flow?

I am trying to design a PCB which has high current traces on it. PCB has 1 oz (35 um) trace thickness. Maximum current flow is going to be 12 Amps RMS. I found this online PCB thickness calculator: ...
4
votes
2answers
2k views

Can a high current trace be on outer and inner layers at the same time?

EDIT, COMMENTS: TL;DR: Data doesn't conclusively suggest you can do this, but it seems to be worth trying. The data from IPC-2152 (more in the answers below) is intriguing, but doesn't seem to ...
4
votes
2answers
5k views

Controlling multiple motor drivers with one Arduino

I have one Arduino and I need to be able to control five to seven 12V motors that each draw about 4 amps. Would I be able to use four Sabertooth 2X5 Regenerative Motor Drivers for this? Each driver ...
3
votes
5answers
548 views

Getting ~600W of power to 2048 LEDs

Despite my Computer Systems Engineering degree, I haven't played with electronics for over a decade, and I'd like to get back into it. I have a project idea, and I think I've got all the design leg ...
3
votes
2answers
1k views

Op-amps, why do they have such low output currents

An introduction to my question is that ultimately op-amps drive something with their output stage (i.e., they source or sink current). I am looking specifically at the current sourcing scenario for ...
3
votes
1answer
1k views

What is the ideal shape for rail-gun?

I was trying to create a low voltage (30V) rail-gun. I have quite a hard source of power that doesn't drop voltage upon current drain, further more, this source is re-inforced by big Tesla capacitors. ...
3
votes
2answers
767 views

Designing a high-power PCB

I'm trying to build a Raspberry Pi cluster (at least 32 Pi's) and I need a convenient way to power them all. So I'd like to design a power distribution board. The distribution board will have USB ...
3
votes
2answers
549 views

Is it possible to switch relay above the power spec?

I am planning to use a DC drived SPST reed relay. Below I include the spec for voltage, current and power ratings. Contact Rating: 200W Carry Current: 5A Switching Current: 3A Switching Voltage: ...
3
votes
3answers
447 views

What terminals of bridge rectifier to use, if I want it to behave as a high-current diode?

I have a 12V power source that can deliver 25A (DC). I intend to use something around 15A .. 20A on a circuit that includes a diode. However, I can't find a diode that can handle that much current, ...
3
votes
2answers
2k views

How do plasma lamps work? [closed]

I've been trying to understand how plasma lamps (or plasma globes, according to Wikipedia) work and why you don't die a horrible fiery death when you touch them. What I've got so far is that the ...
3
votes
3answers
1k views

Why doesn't a high current transformer get damaged when shorted?

In this video a high-current transformer secondary coil is shorted with numerous thick pieces of metal - pieces of rather thick wire and a knife blade. All those pieces either get red-hot or just melt....
3
votes
2answers
192 views

Waterproof Fan Failing In A Chamber With 100% Relative Humidity

So I've built a aeroponic tower that uses an ultrasonic atomizer instead of spray nozzles. This approach is called "fogponics" across the hydroponic community. My Problem is that I have to run a fan ...
3
votes
3answers
3k views

Possible to parallel PC power supplies & increase voltage to 14 VDC?

I'm in need of 14 VDC @ 100 amps. Switching power supplies are available but too costly. I have enough supplies left over from various desktops to assemble such a beast it's just how? This is to power ...
3
votes
1answer
86 views

How to design a contactless mechanical shaker [closed]

I am trying to design a circuit to make an inductor oscillate with high-current (around 50A) at a low frequency. The inductor will act as a high-powered electromagnet. Most designs I've worked/messed ...
3
votes
2answers
4k views

Switching high current and high voltage for coilgun

I am building a multi-stage coilgun and need to be able to electrically switch 450V and over 100A somehow (virtually shorting large capacitor bank)... I've tried using IGBTs but fried them. I also ...
3
votes
1answer
182 views

High current plasma jet striking circuit

A little background: I'm a mechanical engineering graduate student with a focus in materials, so electrical engineering is not my core background. I'm conducting research on plasma surface treatment ...
3
votes
2answers
1k views

How to pick the right capacitor for device with significant current peaks?

I'd like to power the GPRS modem (uBlox LEON G100) with a 4V 500mA power supply. How can I calculate the capacitor parameters so that they will provide the necessary current for TX slots? The ...
3
votes
2answers
271 views

Why do I get high DC current in grid tied inverter output?

Edit: Added gating signal waveforms. Changed some of the graphs, I accidentally put a test circuit waveforms the first time. Current is not that high but offset is there and current is high for a ...