# Questions tagged [power-electronics]

Refers to the conversion of electric power by using solid state components such as semiconductors. Can also generally apply to the field of electrical engineering which works with power electronics.

1,165 questions
86 views

### Are there commonly used equations for short-term overpower of wirewound resistors?

If I have a wirewound resistor rated for 250 W that might need to dissipate, say, 400 W for several seconds, is there a commonly used equation for finding its temperature rise or time to failure under ...
62 views

### How does the wind farm decides to give priority to reactive current during faults or voltage dips? [duplicate]

The grid code for lvrt system says that during low voltage faults wind farm must give priority to reactive current and supply it to grid and decrease the active current. How does it provide reactive ...
26 views

### HID Lamp Ballast Using TI UCC2305

I am trying to control an OSRAM XENARC 66140 35W HID (High-intensity discharge) Lamp with a circuit which contains Texas Instruments UCC2305. I have obtained 4 original lamps from OSRAM and tried on ...
61 views

### Advice for a LiPo UPS

I want to make an UPS using a LiPo battery for a SIM800l cellular module, I have an SIM800l module attached to a 3.7V wall adapter but I also have connected the SIM800l to a 3.7V LiPo Battery, I want ...
116 views

### Analog to Digital conversion for an old analog synth

I'm trying to convert an old analog synth into a digital one. I'd like to bypass the speaker and read the values of the speaker with my arduino. But I don't know how to do it
422 views

### Buck converter design (311V to 3.3V)

I'm trying to make a buck converter which produces an output voltage of 3.3V with a load of around 1 amps when the input is around 220v AC. This basically means converting from 311v DC to 3.3v DC. I'm ...
33 views

### How to get IC IR215x in proteus or multisim?

I need to use a high power IC IR215x for oscillation in half bridge circuit for Compact florescent lamp circuit but I can't find this series in multisim or proteus for simulation. Is there any way I ...
71 views

### What stabilizes the alternators/generators?

I've completed my intern in hydroelectric power plants. I've seen large generators working to maintain voltage in 50Hz. They were turning at 187,5 rpm with 32 poles. But I wondered what stabilizes ...
76 views

### boost converter for ultra low power application

I want to design a dc-dc boost converter and manage power (MPPT) for an ultra-low power fuel which contains input voltage < 1 V and input current < 500 uA. if I choose simple boost converter, I ...
31 views

### How to compute the least overshoot Voltage used by schottky rectifier?

I have a schottky rectifier, it's 11DQ10. I know the Max. Working Peak Reverse Voltage is 100V Vrrm？ If i give it a singal which is a Damping pulse, the first peak maybe over 100V, but the second ...
40 views

### Testing short in circuit

I think it is a very simple test to perform, but I do not know the correct equipment for this. I just have a basic LED circuit, resistor before LED, but I want to test a short in parallel with the ...
77 views

### What is this? Could this help aid in creating an electromagnetic field [closed]

out of a Carvin Dcm1500 amp, and I was wondering if you guys could maybe tell me what it is, what it does, and what the connectors do? Thank you!
151 views

### What causes SMPS voltage ripple?

In many datasheets and application guides there is always an equation for ripple current, because it is fundamental to the operation of a buck or boost converter, but I never see a direct equation for ...
72 views

### How do I understand the effect when the load current is over the inductor's saturation current?

Got a question about the effect after the current over the saturation current in a buck DC-DC regulator. I'm thinking of a theory that due to the fact that the inductance will be downgraded if Isat ...
33 views

### What does it mean to have dual input range?

Hi guys I am looking for a wide range input voltages DC-DC Converter as my inputs would vary from 12,24,36,42Vdc. I found this, the Murata NCS12 series which have an input ranges of 9-36V and 18-75V. ...
37 views

### Relationship between heat coefficient and conductance

I'm involved in a project and part of it involves heat coefficient and heat conductance. What's the relationship between the two, given that the SI unit for heat coefficient is $W/mK$ and the SI ...
160 views

### Why does a wind turbine deliver reactive power to the grid during no winds or when turbine is stopped?

An answer to a previous question explained that a turbine in stop mode may deliver reactive power to the grid. It also takes active power from the grid to run its control system, lighting system and ...
68 views

### What do you think about my PSU design?

I have designed a symetrical PSU using LM317, LM337 plus power BJTs. The desired output range is at least 24V-2V @ 6A max. Altough not shown in the schematic, i plan to add power resistors and a ...
356 views

### How do designers know about kilowatt power of wind turbine generators like 1.5 MW?

Generators and transformers are always designed in kVA because designers never know about the load it will provide power to. Then how do we know the wind turbine generator will deliver 1500 kW or 2 MW ...
33 views

### Automatic Battery Charger that disconnects battery from load ciarcuit when charging. (Power protection)

I am struggling to find resources to guide me in how I learn about power protection. My board draws current from a battery. When I plug in a USB to this circuit, I would like the battery to charge ...
53 views

### Selecting suitable relay for car fuel pump

I am working on a project in which i will control the car fuel pump using relay to turn it on or off. I want the relay to be suitable for keeping the fuel pump continously working for over 15 hours ...
185 views

### Question regarding ripple factor

For the pictures above, I am confused as how to how they got/derived the formulas for the peak to peak ripple voltage (VrPP) and Vdc. So far, I got the output voltage, which is 14.9 volts. However, I ...
66 views

### Why does a turbine with PMSG and full converter system draws reactive power when turbine is stopped or there is no wind?

Our turbine has a permanent magnet synchronous generator and full converter system (rectifier diods for rectification and IGBTs for chopping dc link voltage and as inverters) which means its generator ...
40 views

### initial position detection in BLDC compressor

We have designed an inverter board to control BLDC compressor(air conditioner).The board is up and running.we are controlling(trapezoidal control) the compressor in open loop (without considering back ...
100 views

### What is torque-ampere ratio at electric machines? How it is related with machine efficiency?

When I am reading a journal about SRM (switched reluctance machines) it said that outer rotor design has better efficiency due to higher torque ampere ratio. How it is related with efficiency?
115 views

### What effect would a hydrogen bomb detonated at high enough altitude have on the power grid and solid state electronics?

After reading several dozen reports on EMP effects of nuclear explosions and viewing archived government footage of nuclear weapons testing I have come up empty handed. As for example let us assume ...
95 views

### How to create a shocker device safely, that would electrocute a user with a low charge [closed]

===================================================== As a disclaimer, I'm a novice when it comes to electrical engineering, I have a background in programming in comparison. I'm looking for ...
78 views

### Can this push pull oscillator improved for experimental realization?

I am using the following push pull oscillator circuit is extracted from this Application Note for implementation of a wireless charging system. In simulations, it's efficiency is above above 85% when ...
253 views

### Symmetric vs Asymmetric PWM

I am working on Control of Power Converters, I was reading TI's piccolo DSP ePWM guide and came across symmetric vs asymmetric PWM, I have a good basic understanding about converters, DSP and all. ...
74 views

### Protective diode across dump load

I have a rectified DC Voltage and I will switch in a dump load resistor. I have a 25PV045 Schottky diode connected across it as a flyback to deal with the inductive properties of the load when the ...
67 views

### BQ24133, unable to charge the battery

I have designed the circuit around BQ24133 and in my humble opinion, chose the right components while following the datasheet. I had the PCB made, soldered the components and started testing. The next ...
84 views

### Bypassing DSLR battery to power camera from power supply cheaply with bidirectional optocouplers

I am trying to power my Nikon DSLR with a permanent power source instead of the battery for long captures (overnight) without buying the overpriced battery adapter. I can't simply connect a AC-DC ...
758 views

### Startup problem in boost converter

The figure below is a diagram of a voltage-mode controlled boost converter. I am wondering how experts solve the start-up problem for this converter. Problem: Assume the output voltage is zero at ...
32 views

### Sharing ground between devices connected to same power supply

Several Raspberry Pi projects I've seen, using two modules, have a jumper wire between both GND pins, when a physical connection between one or more pins is needed between both modules. What is the ...
53 views

### How to find SPDT IC that doesn't need a power-supply to have NC and COM connected?

I am looking for a SPDT IC (or circuit?) that connects NC and COM even if the power-supply is off. Basically, I need a TS5A3157 without the need of a power-supply in the NC state. The reason for ...
67 views

### Efficient electronics components [closed]

Imagine budget is not an issue and you are asked to design the most efficient circuit. With efficient, I mean that the power used to perform the functions is used solely for that and is not dissipated ...
123 views

### Auxiliary circuit to reduce power losses in idle stage of this oscillator (wireless power application)

I am trying to implement the following resonant oscillator for wireless power transfer application. There will be a secondary coil coupled with Lp. . Reference - WPT Application Note One of the ...
41 views

### How to sense voltage of 48 V 600 Ah VRLA battery bank for Arduino

How to check the battery terminal voltage across 48 V (2* 24 V cells) of VRLA battery bank (600 Ah). I am not sure whether a voltage divider serves the purpose. Please give me the advice to convert it ...
64 views

### MC34063A Poor load regulation in case of boost and buck converters

I'm using following circuit for a boost converter using MC34063A IC. The circuit is designed for 24 V, 250 mA output. The simulation works fine but the actual circuit on a PCB behaves weirdly. In ...
49 views

### Driving a 12VDC solenoid from a 24VAC signal

I would like to put together a circuit that does the following function: 1) You input 24VAC. 2) It outputs 12VDC pulse to drive a 3W, 4Ω latched solenoid. 3) Once 24VAC is removed, it outputs a ...
32 views

### Forward converter power

I found a TI reference design, which is class 4 PoE with 25W output power. I looked at the schematic and made some calculations: I looked up the transformer turns ratio, which is P:S = 1 : 0.16 (...
82 views

### How to find relationship between switching energy loss, temperature and current in an IGBT

I am calculating the losses of an inverter in Simulink. I used 'IGW25N120H3' IGBT for the inverter. In the datasheet, they have mentioned switching energy losses for 2 different temperatures and from ...
40 views

### Low voltage control of 75V piezo actuator

I am looking to perform position control on a 75V piezo linear actuator with a Raspberry pi. To do so I intend to use a 5V output DAC and some kind of power amplifier to amplify the range between 0V ...
268 views

### Power factor and Harmonics associated with Electric Vehicle charging

What is the power factor associated with (typical) DC fast chargers and onboard chargers in electrical vehicles? Also, how much is the harmonic content (especially triple-N harmonics) associated with ...
45 views

### Driving MOSFETs with Bootstrap connections

I'm designing a type of a buck converter which has the following circuitry. Simulation runs fine on PLECS and I've added three bootstrap connections to drive these high-side MOSFETs (All top three ...
104 views

### High temperature of components to joining & soldering

Please help me to know the best components for the process of welding an electronic circuit to operate it in a very high temperature environment up to more than 600 degrees Celsius? Note: I do not ...
59 views

### Electric Vehicle Charging [closed]

I have a few queries related to EV charging: (1) When we refer to 'X kW' charger, is it that the charger is taking in X kW power and delivering power = X kW times the efficiency of the charger to the ...
173 views

### Ferrite core selection for boost converter using push-pull topology

I'm trying to build a boost converter with the following specifications. Switching Frequency: 100 kHz Maximum Input Voltage: 14 V Nominal Input Voltage: 12 V Cutoff Input voltage: 10.5 V Power ...