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2 votes
Accepted

Maximizing power transfer from 50Hz AC line via toroidal current transformer

Minimum line current 50A means we need to drop maximum 20V to deliver 1kW. I assume we have no way of looping a wire around (power lines are generally solid wire, coated with rigid insulation, and ...
Tim Williams's user avatar
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15 votes
Accepted

Why is the MOSFET in this fan control circuit overheating?

It looks like you have an N-channel MOSFET operating as a "source-follower", otherwise known as "common-drain". That means the source is always a few volts lower than the gate (by ...
Simon Fitch's user avatar
  • 38.9k
7 votes

Why is the MOSFET in this fan control circuit overheating?

The problem is you have the fan in the wrong spot - your MOSFET is operating in its ohmic region. To correct your circuit, tie the source of the MOSFET to ground. And put the fan between the Key ...
MOSFET's user avatar
  • 4,963
3 votes
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How should we calculate L (inductance) value for a transformer

A starting point would be 20 % magnetizing current of your full rated load, in this case 2 VA. At 230 V, that’s 8.6 mA. Z = 2*Pi*L*f. Solve for L. If the transformer would have been 2 kW, about 5 % ...
winny's user avatar
  • 15.7k
0 votes

How should we calculate L (inductance) value for a transformer

The inductance is essentially a characteristic of the transformer core, and rises with the square of the number of turns. If you study the datasheet for a particular core you should find this value ...
Frog's user avatar
  • 7,470
2 votes

Current varies with constant firing time in an SCR

There are many things that affect the charging current of a battery, and the applied voltage is only one of them. The resistance of the battery itself depends on things like its state of charge, its ...
Dave Tweed's user avatar
  • 175k
0 votes

Power IR2110 from a low voltage AC Source

You have connected your "DC Output" of the bridge to the AC input. The cathodes of D1 and D2 are the positive output of the bridge, and anodes of D3 and D4 are the negative output of the ...
Peter Bennett's user avatar
1 vote
Accepted

Using Microchip Technology MCP39F521 (I²C Power Monitor) with 240V

The answers in reference to the comments are: No. If we substitute L2 for the N in the circuit, the voltage divider on V1+ would need recalculating. No. L (or L1 for two phase) is the 0V reference. ...
Kartman's user avatar
  • 6,423
1 vote

Do you know this circuit?

The 2 PNPs form a simple comparator; comparing the emitter voltages. When the 3V3 level is higher than ext_3V3, the right-hand PNP will have a higher VBE than the left-hand one (since the bases are ...
jp314's user avatar
  • 19.4k
2 votes

LiFEpo4 issues and concern

If this is what you intend to do then NO, it won't work. simulate this circuit – Schematic created using CircuitLab
Rohat Kılıç's user avatar
0 votes
Accepted

Confused about layout guidelines for TPS63710 buck converter

It's not much different than having a bypass cap on a normal logic IC with one supply and one ground pin. Or rather, a logic IC with built-in regulator and the logic that uses the output of the ...
Justme's user avatar
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1 vote
Accepted

How to measure battery voltage during charging?

Will I read battery voltage/charger voltage/intermediate voltage between 15V and 12V. No. If the meter probes are placed across the battery, you will measure the sum of the battery voltage and the ...
RussellH's user avatar
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1 vote

How to measure battery voltage during charging?

If your battery is 12V and charger is 15V then connecting the charger to the battery should show 12V or something very close to 12V as the battery voltage cannot jump instantaneously as it needs ...
Justme's user avatar
  • 159k
1 vote

How to measure battery voltage during charging?

the battery voltage or the charger voltage or some intermediate voltage. Yes, yes, and kind of yes. By definition, the battery voltage and the charger voltage are exactly one and the same because ...
Davide Andrea's user avatar
0 votes

Is the zeta DC-DC converter topology scalable to 50kW / hundreds of amps?

For this powerful of a converter, you typically don't want to use a standard hard-switching topology. At 50 kW, even 90% efficiency means that you have to dissipate 5 kW of heat! You need to target ...
Hearth's user avatar
  • 35.2k
1 vote

Designing a 24 V output relay using PCF8575

You are not telling how exactly you are connecting the optoisolator LED input to the IO expander. Since it does not work, it is a safe guess that you connected the anode to IO pin and cathode to GND. ...
Justme's user avatar
  • 159k
0 votes

I need a sensor setup to detect if something passes through an opening after I click a button

To make your pill dispenser work smoothly, you'll need sensors and a setup that detects when pills pass through each slot. Here's how it could work: attach a sensor to each slot where pills come out. ...
Gonzalocasey's user avatar
0 votes

PCB inverter design

But how to design a PCB for an inverter or power converter without using separate power supplies for microcontrollers and gate drivers... designing only by using input supply Use is made of isolated ...
Andy aka's user avatar
  • 465k
0 votes

Peak Current in Electrical Discharge Switch FET

I don't know that a very full answer can be provided without more details, but generally I think you are thinking about this the right way. Assume there are designs that operate without discrete ...
Matthew Huber's user avatar
0 votes

Do we need MPPT in grid synchronization and string inverters?

As stated by Dave Tweed we use an MPPT only when we have a large sink that can consume a huge amount of current. At times of synchronizing and load providing in string inverter the load is limited and ...
kam1212's user avatar
  • 669
3 votes
Accepted

Designing Optocoupler circuit

The 6N137 is built for logic signals, so both input and output have only two states, high and low. The recommended operating conditions show that the input is guaranteed to be read as high when the ...
CL.'s user avatar
  • 19.6k
4 votes

Designing Optocoupler circuit

The 6N137 is an optocoupler with logic-level outputs. If you want a plain optocoupler, perhaps look at 4N25 and similar. You can see the internal functions in the 6N137 datasheet, and the current ...
jonathanjo's user avatar
1 vote

Connecting the LC circuit to dc voltage source without transient

I have been looking for a control algorithm how to achieve a state when both of the upper transistors are open and this state has been achieved without transient in the LC circuit. I don't believe ...
Andy aka's user avatar
  • 465k
0 votes

Help Needed with Compact Circuit Design for Pulse-Triggered Switch-Off Sequence

One of solution is below: A monostable gets triggered with input pulse. After delay of monostable generate a trigger pulse setting the Latch low.
Michal Podmanický's user avatar
0 votes
Accepted

Help Needed with Compact Circuit Design for Pulse-Triggered Switch-Off Sequence

Based on the updated information - Because of the requirement to ignore subsequent input pulses, you still need a latch circuit of some kind. Also, the shift register input probably would not like a ...
AnalogKid's user avatar
  • 21.4k
0 votes

Help Needed with Compact Circuit Design for Pulse-Triggered Switch-Off Sequence

I ran into a similar problem a few weeks ago (with different logic), what I found is a micro is a way to go because you can get very small micros. You do have the challenge of programming them but ...
Voltage Spike's user avatar
  • 84.8k
5 votes
Accepted

How does MPPT maintain a constant voltage?

MPPT is not a specific "algorithm", it's a concept. When you pull more current from a solar panel, the panel voltage drops; if you pull too much current, the voltage collapses and you get ...
Boann's user avatar
  • 474
3 votes

How does MPPT maintain a constant voltage?

An MPPT can only track the maximum power point if the load can swallow the power, regardless of how much. Usually, you're either charging batteries or feeding the grid. In that case, the load is in ...
John Doty's user avatar
  • 4,867
2 votes

How does MPPT maintain a constant voltage?

Your first figure has a flaw. It's lacking the input capacitors of the DC-DC converter. Those are massively important. Let's assume that the L is so big that the current is approximately constant, i.e....
juhist's user avatar
  • 1,752
3 votes

How does MPPT maintain a constant voltage?

The power converter shown in the MPPT is known as a buck/boost converter; this is a type of DC-DC converter that can produce an output voltage that is either lower (buck) or higher (boost) than the ...
Fabio Barone's user avatar
  • 5,327
5 votes

How does MPPT maintain a constant voltage?

As with any regulator the output voltage can be made stable/fixed/constant with varying input voltages. The diagrams are just so simple that they do not show the presence of feedback, so the output ...
Justme's user avatar
  • 159k
0 votes

AC capacitor computational problem using calculus

Since current \$i(t)\$ is discontinuous at time \$t=1\mu s\$, the calculation must be piecewise, the sum of integrals over two distinct intervals, but the equation for \$i\$ during each interval is ...
Simon Fitch's user avatar
  • 38.9k
4 votes

Switching between batteries and a power supply

Here's the schematic using Schottky diodes having a low forward voltage drop. A 14 V power supply is used, presuming a 12 V system backed up by a 12 V sealed lead acid battery. It doubles as the ...
vu2nan's user avatar
  • 18.9k
1 vote
Accepted

How to determine the correct direction of the transformer winding (photo)

Your primary winding is connected to your circuit via wires (it seems) so, once you have decided where your secondary winding wires terminate, you can do a little test with a signal generator and an ...
Andy aka's user avatar
  • 465k
0 votes

Yokogawa WT3000 don't boot

From the information in the question it isn't clear what the failure mechanism is, but for general debugging suggestions about checking if the Altera EP1C3T144C8N FPGA configuration is valid: Check ...
Chester Gillon's user avatar
2 votes

Switching 5 kV for a neon sign

As an idea for individual 12V->HV supplies, here's a high-volume, novelty quality power supply for a neon tube in the 30cm range. It was the silhouette of a skating hockey player, in a couple of ...
Spehro Pefhany's user avatar
0 votes

How to control lightweight pull-up and pull-downs from GPIO-style pins?

There are no markings on the image of the board. If the actual chips are marked AGCx (where x could be anything) then they are probably MP2315 chips, in which case you can try connecting 100kΩ in ...
Spehro Pefhany's user avatar

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