Questions tagged [load]

An electrical load is an electrical component or portion of a circuit that consumes electric power. This is opposed to a power source, such as a battery or generator, which produces power.

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3answers
444 views

Controlling 13 outputs with a mcp23017 or 74hc595 and two uln2003?

I need to drive 13 20ma (constant) loads with a single microcontroller with only 5 available pins. My first thought was to just use a mcp23017 or some 74hc595's but after reading the datasheets it ...
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1answer
93 views

Why can the loading resistor and capacitor let the unloading waveform become from negative to positive voltage?

Fig(1) is part of schematic,and it generate a sine wave .Fig(2) shows two waveform which are with load and unload,i can understand that these two waveforms will be different because of loading,but why ...
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1answer
730 views

Single phase heater loads on 3 phase supply

I have two single phase heaters (same rating) that I have to connect to a 3 phase supply. Say for example the rating on the heater is 1000W, 208V. And the supply is 208V,3phase,60Hz. I connect heater-...
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2answers
3k views

Why does an induction motor draw more current when the load is increased?

I am aware that a coil has inductive reactance when powered by AC besides the еlectrical resistance which is typically very low. Considering the fact that reactance is proprotional to the inductance ...
1
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1answer
134 views

Adding a temporary load to a power supply

I have an isolated switching power supply which takes in 30V and outputs 55V 1.5A. It's a power source for a PoE+ powered device. When the device which is supposed to be powered is not connected (via ...
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1answer
449 views

Load sharing between 3.3V regulator and LiFePo4 battery

I am trying to design a supply for a relatively low power (<100mA) device with a LifePo4 (14500 format) battery and a USB input. Everything is running at 3.3V, and therefore I would like to avoid ...
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4answers
2k views

When transformer rating is in kVA, why load is mentioned in WATTS?

The transformer rating is given in kVA, but the load connected is always considered in watts. Why? Eventhough, the load active power is represented in watts it has some reactive power, right? Is ...
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2answers
698 views

Can any type of op amp output stage be forced into Class A operation?

I'm trying to choose a good op amp for a Class A small signal audio amplifier circuit. I've done my research and understand the use pull up or pull down resistors externally to force Class A ...
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1answer
176 views

What is the purpose of this FET load?

I'm used to seeing a load resistor in the place of the yellow highlighted (Q2) section of this FET amplifier circuit. This is the input section of a guitar overdrive effect, so any distortion created ...
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1answer
87 views

Building a numeric potentiometer for AC current

I'm building a bench to calibrate a device that measures AC currents. As I won't build something accurate, the current will be measured with a current clamp and a multimeter (voltage mode). For the ...
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1answer
367 views

How a current buffers works, I want to make (1-5)V to (4-20)mA V-I converter, how can I make this circuit load independent?

I want to make a 1-5V to 4-20mA Voltage to Current convereter. I choose this circuit. The circuit is working for only 250ohm load the conversion ratio is 4. But I want to make this circuit load ...
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0answers
2k views

How to plot an impedance vs frequency graph in Proteus?

I'm designing a circuit that simulates the impedance behavior of a real world speaker, which is not purely resistive and looks something like this: I already got the basic circuit but need to tweak ...
0
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1answer
594 views

Off-load voltage of wall-warts

I need to regulate an incoming DC supply from a wall-wart down to 5 volts. I'm experienced with designing power supplies with ordinary transformers. In this situation, the maximum voltage I can expect ...
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2answers
706 views

OpAmp with high output current and capacitive load

I am trying to solve the following problem which - until today - I thought to be a trivial one: I have multiple reference voltages (from different sources) that I need to buffer and/or invert, filter ...
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1answer
918 views

Buck converter without load - is it dangerous in long term?

As a followup to my previous questions (Q1 - circuit diagram is here, Q2). I disassembled the LED bulbs, cleaned and resoldered the components on the DC-DC converter boards, replaced caps, and ...
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3answers
618 views

Can a Li-ion battery be discharged in CV mode?

I have a load which can also be set to "Battery test". I can easily discharge a Li-ion battery using the CC (contant-current) mode, which is also a condition recommended by the manufacturers. For ...
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1answer
131 views

Input voltage drop [closed]

I have a circuit, the characteristic of the load is unknown, most probably resistance and capacitance, the input for the circuit is %v and frequency is varying from 10 Hz to 30 MHz. once the input ...
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3answers
656 views

Output voltage of an amplifier circuit

I found this note on a devicesheet: I'm asking about the output current: How can we fin Iload = Vout/(RS*R2/R1) ? For our example, we will take Vcc = 3V, we call Va the node crossing R1 and RS wires....
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2answers
211 views

Questions on load modulation, Doherty PA

I was unable to understand a bunch of stuff related to amplifiers. Specifically my questions are as follows: What is load modulation? If i have a load of impedance of 10 ohms physically, then does ...
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1answer
313 views

Variation of generator working frequency with load

I am confused with problem no 68. I have added my attempt. I am getting optionA but the book says it should be optionB. Please guide me where I am doing mistake.
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0answers
32 views

Problem with AC powered system

I have a system (car simulator) which is powered by a 220Vac 60Hz. Within the system there are 6 switched sources, 4 of 24 Vdc, 1 of 12Vdc and 1 of 5Vcd. Loads 1,2 and 3 are dc motors 24vcd. Loads 4,5 ...
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2answers
2k views

Transistor as a switch, what does the inductor do?

I dont understand what the inductor in this circuit is actually doing. Is there a current flowing through the coil when my input is 0 ? If so, it should be DC so the coil isnt really doing anything ...
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3answers
4k views

Calculating load % of AC motors when operated at a frequency less than rated value

I have a three phase induction motor with name plate details: frequency = 50 Hz PF = 0.86 RPM = 1475 efficiency = 94.2 voltage = 415 V ampere = 77 Amps HP = 60 Now this motor is operated at 40 Hz ...
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2answers
424 views

Using series P-Channel MOSFETs for high-side switching

I am looking at using two p-ch MOSFETs in series as part of a high-side load switching scheme, and do not understand the following circuit behaviour. In simulation of the simplified schematic below, ...
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2answers
494 views

What are those nonlinear loads in real microgrids/grids?

I have read in literature that nonlinear loads can impact on the operation of the so called microgrids. However, when I heard nonlinear loads I think in electronic devices such mobile phones or ...
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1answer
2k views

Can anyone please help me with this ETAP Project?

I'm trying to run the load flow study, but instead I'm getting this error. Error 101-01: [Bus 2] Bus base kV is out of 40% range from bus nominal kV. Error 722: [XFMR 1] 2W transformer secondary kV ...
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3answers
170 views

Why did spilled coca-cola on a terminal strip cause this odd voltage problem?

I recently repaired a vending machine that had coca-cola spilled on a terminal strip. A 9.5V source from the strip measured correctly on a DMM when there was no load on it but dropped to 2V with its ...
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1answer
5k views

Safe load on a 40 VA Transformer

I apologize ahead of time for this elementary, and quite possibly poorly posed, question, but I am a coward and want to make sure that I am understanding everything correctly, and not blow four motors....
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1answer
96 views

Will this inverted switching circuit to drive 4 Ohm heater work?

I want to switch a heater, and learn to build some electronics while doing so). The heater is a heated print bed, from the Ultimaker original heated print bed kit (no longer sold I think). The problem ...
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1answer
240 views

Open Loop Buck Converter - Regulating output voltage during rapid load change

I am designing an open loop buck converter. I want to limit the change in output voltage during rapid load change to a certain value. How should I modify my circuit design to achieve this goal?
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1answer
366 views

Voltage source and its load resistance matching

i have implemented DAC controlled DC voltage source. I'm having trouble understanding physical reasons for voltage error due to load resistance change. My circuit desing was taken from DAC ...
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1answer
6k views

Why does armature current increase when load on the DC motor increase?

Does this load somehow decrease the resistance of the armature causing it to draw more current? Is it due to the torque the load will give to the motor?
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1answer
1k views

Calculating voltage gain for AC analysis

Why do we connect load resistance to the output of re model while calculating voltage gain This image shows calculation of voltage gain for common base configuration of NPN transistor
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2answers
2k views

How to correctly calculate load on a DC motor

What bothers me is the meaning of no load current (free current) which is the source of my problem. I want my circuit's MCU to warn me if a motor exceeds 30% load. But how to calculate load? There is ...
0
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1answer
780 views

Overcurrent and overload, current and load

I know that current is measured in Amperes, and is tied to voltage and resistance in a circuit by Ohm's Law. Load, on the other hand, seems to be a concept tied to the number of appliances connected ...
1
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2answers
72 views

Help using Load Pull in ADS

I'd like to ask for some help with performing a Load Pull simulation in ADS. I tried using the DesignGuide utility but am not sure how to connect the Load Pull Instr shown in the attachment and which ...
0
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1answer
371 views

What is the best and cheapest load to test a variable frequency drive at full load?

what is the best and cheapest load to test a variable frequency drive (1 HP VFD) at full load? Maybe a centrifugal pump ? Thanks in advance
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2answers
97 views

Adjustable LDO output became unregulated

I designed a simple LDO circuit using LM1084 (circuit A as in the picture) to power a small MCU board (circuit B) and the two circuits are connected with a 40cm wire because of installation constraint....
0
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1answer
203 views

Relay's maximum rating current and voltage

I'm looking at this Form C relay: IXYS LCC110 Its max load current is 120 mA and max voltage is 350 VDC. My question may be dumb, but can I use this relay to safely control a load that is only 5V but ...
0
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1answer
56 views

Step response of power load switches

Many load switches implement a fix or controlled slew-rate of its output current in order to prevent inrush currents. I was wondering what is the step response of this kind of switches after the slew-...
2
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3answers
889 views

Clamping Constant Current LED Driver Output Voltage

I want to test a Constant Current LED Driver across its voltage range without using a LED for test purpose. How can I clamp the output voltage of this driver to required voltage levels? For Example -...
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2answers
2k views

Using an AC relay for DC switching, safe limits

I have an relay that's rated for a 250VAC, 16A load. Would it be possible to also use the same relay for say a 25VDC, and less than 1A load? From here, relay power ratings - AC vs DC , it seems to ...
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1answer
2k views

How do I calculate KVA and KW to fill out this load sheet ?

I'm in the process of trying to build a small hobby farm from scratch. One of the initial steps is to get temp service on the property, and to do so I have to fill out an electric load form. I will ...
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1answer
92 views

Question to “Start-up into resistive load” diagram of LTC3106

There is a diagram on page 7 of the LTC3106 (Datasheet) named "Start-up into resistive load" and i couldn't find any explanation on the internet how to understand it. My assumption is: This diagram ...
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1answer
58 views

How are the motor ratings required for a load calculated? [closed]

I want to calculate how much weight can be carried by dc shunt motor. Until now I did have not tried to do so, but I have lab experience in applying a braking load. I would like to know how a moving ...
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2answers
44 views

Coupling servo-motors [closed]

My application is a small robot-ic head - lets say for a scarecrow. It is going to be moved around frequently, during operation too. I obtained a lot of these "hobby" servos that are used in RC ...
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0answers
40 views

Load Resistance

Suppose we have this circuit (I do not include bias): using this model: What's the difference between having: 1) \$R = \frac {V_ {CC}} {I_C} \$ 2) \$R = r_0\$ \$I_C\$ is the collector ...
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2answers
57 views

Adding a constant load to the input of an Opamp

I was looking at this circuit, and there was a resistor connected to ground after the output of a signal generator(50 ohm on the top left) . The explanation was that adding it allows the signal ...
1
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1answer
596 views

how to design a microgrid

I am working on designing a theoretical microgrid for a school building, but before I can even select theoretical components, I need to select what the structure of my microgrid will be. Here's what ...
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4answers
2k views

Constant current load

I was trying out some different designs of constant current loads a.k.a dummy loads and stumbled upon this one on google images search. I do have a question or two to it's operation since on ...

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