# Tag Info

### What does power balance and voltage balance of a circuit tell? How to calculate them?

I am not familiar with these terms so I can't say they are widely used where I have worked but I can take a guess at possible matches. Power balance sounds like power CONSERVATION, which as you know ...
• 9,682

### Does anybody think this design has been able to show more energy produced than used?

No. The rope has friction. The pulleys have friction. The motor bearings have friction. Bending a rope takes energy. The drawing shows three motors but no generators, so the whole thing is running ...
• 12.6k

### Does anybody think this design has been able to show more energy produced than used?

Short Answer: No! Pepetuum Mobiles never work. And a pulley system does not reduce to work required. It just reduces the force required but at the price of more distance. And since every pulley system ...
• 1,475

### MOSFET Power Switching Circuit

The problem might be the internal drain/source capacitance of the P fet. If you connect your battery, the voltage of the P fet source rises very fast and feeds this delta-U forward to it's source. ...
• 196
1 vote

### Is the consumption of a DC motor linear?

The mass of the load doesn't matter, it's the energy expended. If you're moving it downhill, it will take virtually no energy and, with some motors, might give some back. Let's assume you mean "...
1 vote

### How to find the maximum power dissipation or Thermal resistance (J-A)

Web search results may vary. It depends greatly on PCB & heatsink design, convection, airflow or enclosed https://www.datasheetarchive.com/pdf/download.php?id=...
1 vote
Accepted

### How to find the maximum power dissipation or Thermal resistance (J-A)

See section 7. The storage temperature is listed as -65 to 150 C. This might mean that Tjmax is 150 C. But there is no guarantee that it will function correctly at that temp. See note 7-4. The maximum ...
• 24.2k

### I've designed a new style of ac alternator where both the stator and the rotor rotate oppsite directions so that rpms multiply by each other

Unfortunately your conjecture that the rpms will multiply is incorrect. The governing equation behind motors and generators (and alternators) is the faraday induction law: https://en.m.wikipedia.org/...
• 487

### How to reduce power drawn by a resistor heater?

Typically, industrial power supply is 3-phase. You can split power between 3 phases (3 heaters, star or triangle, depends of voltage you wish) so reduce current through every single phase. Another ...
• 176

What they call "loading factor" seems to be what is usually called "load factor" (in the UK at least). This is measured over long timescales - like years - and includes downtimes ...
• 65.8k

### How to reduce power drawn by a resistor heater?

In addition to other answers, the simplest approach I can think of is to reduce the diameter of the wire. That will increase the resistance and drop the power. In addition, the smaller-diameter wire ...
• 57.9k

### How to reduce power drawn by a resistor heater?

220 Volt / 6 Ohms = 36.6 Amps * 220 Volt = 8066 Watts 120 Volt / 6 Ohms = 20 Amps * 120 Volt = 2400 Watts Reduce the voltage. At these currents you likely want a transformer. Or get a 120V power ...
• 70.7k

### How to reduce power drawn by a resistor heater?

Since your application (electric furnace for fused metal) is not going to need quick reaction times, one flexible way to control the heating power is to use PWM (Pulse Width Modulation), as mentioned ...

### How to reduce power drawn by a resistor heater?

You can put a resistor in series with the 6 ohm heater , in order to reach 2400W of power you will need a smaller than 6 Ohm resistor.
• 464

### How to reduce power drawn by a resistor heater?

If you need 8067 watts of power to heat whatever it is you're heating, then... you need the watts, can't reduce the power. If you do not need the watts, but find you need less watts, then you can use ...
• 57.5k
1 vote
Accepted

### Transformer ratio of a transformer that connects a generator to a MV grid?

I try to answer your questions below. how should I modify the transformer ratio when the rated power changes? You should not change the voltage ratio due to the rated power of the generator. ...

### Voltage is below 380

You need to find out why your power line voltage is so low. I believe the nominal voltage should be 440 VAC. If you are getting below 370, your power grid is dangerously close to failing. I assume ...
• 57.9k

### How to calculate the total power of a LED using solid angle?

Vishay has published how to measure light density and intensity at a conical distance in a document from the datasheet page you posted. "General Information Measurement Techniques" ...
Accepted

### Conceptual understanding of phase power vs. line power

Conceptual understanding of phase power vs. line power There aren't separate phase power and line powers. There is just one value for power, which you can work out for a balanced load using either of ...
• 2,605

### Voltage is below 380

I think what you are looking for is called a Servo Controlled Voltage Stabilizer, e.g. implemented as variable transformer that automatically adapts its transforming ratio in order to compensate input ...
• 15.7k

### How to regulate 5V 3A to 3.3V for ESP32 and level up 3.3V to 5V on a PCB?

In addition to what's already been said - yes linear regulators do produce a whole lot of heat, they have poor efficiency compared to switching regulators. Going from 5V to 3.3V isn't a big step ...
• 13.5k

### How to regulate 5V 3A to 3.3V for ESP32 and level up 3.3V to 5V on a PCB?

The linear regulator burns excessive power as P = V * I, so it burns off the extra voltage (while the current stays the same), but the power dissipated is that ...
• 3,286
Accepted

### How to regulate 5V 3A to 3.3V for ESP32 and level up 3.3V to 5V on a PCB?

The linear regulator burns the extra voltage as heat. Example: ESP32 draws maximum 240mA. Let's use 300mA instead, assuming the ESP32 will draw a bit of extra currents to light LEDs, etc. At this ...
• 57.5k

### How to regulate 5V 3A to 3.3V for ESP32 and level up 3.3V to 5V on a PCB?

I think LM1117 is enough to drive your ESP32. The maximum output should be around 2.5W. To protect your LED, simply check the maximum allowed current of your LED and calculate the corresponding R3. ...
• 11

### Voltage is below 380

The problem am facing is voltage supply is variable, that is from power supplier company. Most of the time I get voltage around 390 but. sometimes it drops to 375 or below. At that time motors couldn'...
• 9,678
Accepted

### How can I make this variable power supply go from 1.25V and -1.25V to 0?

Since you have supplies of both polarities, you could make a regulated -1.25 V supply and connect R3 to that instead of to Ground (and do likewise for the negative supply). These +/-1.25 V supplies ...
• 51.2k

### How can I make this variable power supply go from 1.25V and -1.25V to 0?

How much current do you need? A buffered op-amp could source or sink between +12 and -12. This answer has some circuit ideas that could do the job: How to increase the output current of a dual supply (...
• 40.2k
1 vote

### How can a reed switch be used for high current applications?

You will want a protection circuit (or BMS, stands for Battery Management System) for the LiPo pack, to implement overtemperature and overcurrent cutoff. The protection circuit will have a MOSFET that ...
• 4,680
Accepted

### Power supply overload protection work around

I need to switch on a contactor that uses around 3.2A inrush current for around 20ms... ...the power supply breaks down the output voltage around 3.1A ... at 3.1A, the output voltage of the power ...
• 12.3k

### Power supply overload protection work around

First, you’ll need a representative SPICE model for the contractor coil. Measure the inductance and series resistance of the contractor coil – using an LCR meter, as it’ll do both at once. Then ...

### Power supply overload protection work around

I'm not sure you'd actually want to do this... adding a C in parallel to the relay coil will form a resonant tank circuit. When power is removed, the the 3.1A stored in the relay will start ...
• 11.7k

### How can a reed switch be used for high current applications?

For long-term reliability, a 60 A load requires relay contacts rated for at least 100 A. The coil current for such a contactor almost certainly is greater than the reed switch rating. There are at ...
• 12.6k

### How can a reed switch be used for high current applications?

Don't use the reed switch directly. Use the reed switch to switch the coil of a larger relay. Alternatively, use the reed switch to switch the gate of a FET large enough to handle to load current.
• 57.4k

### dB (decibel) is a relative measure. It's not a physical unit. Decibel relative to what?

dB is a ratio. dBx is with respect to the reference level x. Originally, it was a power ratio, but it has since become common to also use it for a voltage ratio, and regardless of the impedance levels....
• 140k

### dB (decibel) is a relative measure. It's not a physical unit. Decibel relative to what?

dB is a ratio of two power levels (at least originally). Common practise is to give it a suffix indicating what the reference level is, so for example dBm is power relative to 1mW, dBW is power ...
• 16.1k

### dB (decibel) is a relative measure. It's not a physical unit. Decibel relative to what?

The reference point is arbitrary. Per Wikipedia the reference level most commonly used for sound in air is 20 μPa which roughly corresponds to the sound of a mosquito flying 3 meters away.
• 1,306

### dB (decibel) is a relative measure. It's not a physical unit. Decibel relative to what?

It is relative to any reference value you want to use to know how your value compares to the reference.
• 87.1k

### Galvanic Isolation in Automotive Environment

Assuming this is what you got... The problem here is the ground loop. The voltage reference for your signal is the "0V" point at the source (in this case the computer playing the music). ...
• 57.5k
Accepted

### Apparent power for assymetric configurations

Yes. For a Wye source with a balanced load you also have $$S = 3V_{phase}I_{line}$$ where $V_{phase}$ is the voltage between any one phase and neutral. ($V_{line}$ is, of course, the voltage ...
• 2,605

### Measure power with multiple measurements

It is incorrect to multiply the RMS values. If the V is constant, then there is no need to use its RMS value --and for small amounts of ripple, then a straightforward average is OK. Given that V is ...
• 12.4k
1 vote
Accepted

### How do you add multiple system voltages to a design?

Devices that include multiple switching controllers in one package are known as PMICs or multi-channel regulators. These are commonly used in microcontroller, microprocessor, or system-on-chip ...
• 560

### Could someone please tell me what each of these components are?

The components have been identified. 'WP' may stand for Water Pump. The hydraulic system may be water-based not oil-based.
• 9,678
1 vote
Accepted

If the incoming E-M wave can induce a voltage won't it accelerate or decelerate the electrons in the wire and doesn't this acceleration cause further radiation (lets call it secondary radiation) of E-...
• 12.3k

If you have a power supply with V volts, connected to a resistor with V volts, is the resistor a power supply? A receiving antenna can be considered to be a negative power supply, just like a resistor,...
• 3,918
1 vote

### Can a CPU heatsink be used to cool a TO-3P or a TO-220?

First of all, there are heatsinks designed for TO-220. Second, your main concern is mechanical contact. A CPU heatsink generally has much better thermal resistance than a TO-220 heatsink due to the ...
• 6,650

### Determining the characteristics of an unidentifiable low-frequency transformer

It sounds like you already have the windings identified. For other readers I'll give a tip. When measuring an unidentified transformer, always apply your excitation to the highest resistance winding. ...
• 140k

### S = VI*/2 derivation

The way to derive $${S=VI^*}$$ is as follows. Let there be a voltage $${V\angle\theta_v}$$ and a current $${I\angle\theta_i}$$ in a phasor equivalent circuit in the steady state. In the time domain, ...
The reason $${S=VI^*}$$ is as follows. Let there be a voltage $${V\angle\theta_v}$$ and a current $${I\angle\theta_i}$$ in a phasor equivalent circuit in the steady state. In the time domain, the ...