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0
votes
2answers
43 views

Load-line analysis derivation

I'm trying to get a better handle on the derivation where load-line analysis comes from. This is because I have a system that essentially has two different loads operating on a single diode and I'd ...
-1
votes
0answers
63 views

Would my design benefit from a shunt regulator? [closed]

I am trying to simulate field operation bulbs, with LEDs, for lab testing. The difficulty in this is that LEDs draw almost no current, and I have to have 1 amp of draw. I also want to combine them ...
4
votes
1answer
96 views

Arduino Boost Converter. Connecting load makes converter non functional

I am trying to build a DC-DC Buck-Boost Converter using this basic schematic and an Arduino with the analogWrite() function as my PWM generator. I only want to step up 2.4-3V to ~5V. If it's just the ...
3
votes
2answers
79 views

How can I calculate the inductance of the primary of a transformer given a specific load on the secondary?

Inductance in the primary of a transformer decreases as the load on the secondary increases. How can I calculate the inductance of the primary coil? What if it was step up or one to one ratio?
3
votes
5answers
102 views

BJT input connected to another BJT's output and loading effects

Sedra & Smith Microelectronics, example 6.10, page 390. They ask us to analyze a BJT circuit. Here it is: simulate this circuit – Schematic created using CircuitLab In the next ...
0
votes
0answers
43 views

Protect power supply from mechanical switching of load

I'm powering a resistive load from a laptop PSU. The circuit will be closed and opened using a mechanical switch. I am worried that the switching will damage the PSU due to inductances in the PSU. ...
2
votes
2answers
75 views

General 3 Phase Motor Inductance Question

I know that motors are inductive loads. Does the inductance of a 3 phase motor depend on the load on the motor?
3
votes
1answer
132 views

Complex Dummy Speaker Load Impedance

I would like to create a dummy load for this so-called "Deacy Amp": This is a low power germanium transistor / transformer driven push-pull amplifier for driving a small 4 ohm or 3.2 ohm speaker. ...
0
votes
2answers
91 views

ADC Value from load cell to MSP430 not correct

I have a 1000lb load cell (LC302 from omega) being fed through an INA125 OPAMP then to the ADC10 of a MSP430G2553 with 2.5V as reference. 2.5V is coming out of the OPAMP that's being fed into the ...
1
vote
1answer
51 views

How to understand synchronism?

In my job, I frequently compile a rough rundown of the power consumption of simple industrial plants. Here, you always encounter a "synchronism" factor, besides how many motors of which power and ...
1
vote
1answer
96 views

How could I efficiently implement this “TTL load”?

I'm attempting to test a parameter of an IC to the specifications listed in the data sheet. The data sheet describes the following load circuitry for the output: The data sheet notes that CL be ...
0
votes
1answer
55 views

Frequency and magnitude of power variations in a DC circuit.

I have a 5 V 5 A power source which is connected to a simple development board with a processor that draw current dependent on utilization. I use a multimeter that measure 1000 samples / s to measure ...
2
votes
2answers
219 views

How does a real current source change its pd to keep constant current

An ideal current source is able to change its potential difference at the output to keep the same current at the output regardless of the load imepedance there. Real current sources are able to do ...
1
vote
1answer
70 views

Saturating a BJT with an open load

Is there some drawback in having a BJT transistor saturating without a load? The scenario is this: BJT is driving a relay, but there is a switch to have the relay always on or off leaving the BJT ...
1
vote
1answer
116 views

What's the input resistance of an opto-isolator?

I need to sense if a 48 volt power supply is supplying voltage or not, I plan on doing this with a opto-isolator and I am happy with the output circuit from isolator. Can I connect the input of the ...
-2
votes
2answers
239 views

What amplifier circuit to use for a wheatstone bridge force transducer [closed]

I would like to amplify the signal from a force transducer which can measure load from 0-1500g. The object i am using is less than 1 gram. I would need an operational amplifier. I would like to know ...
0
votes
1answer
78 views

Drawing VTC from IV

So I am given the IV characteristic plot along with the resistive load circuit which looks like: The load is a 25k resistor. I want to understand how to actually do the problem which is why i didn't ...
0
votes
2answers
1k views

How to interface a digital scale strain gauge weight sensor with a microcontroller? [duplicate]

Possible Duplicate: How to interface a digital scale strain gauge weight sensor with a microcontroller How to interface a digital scale strain gauge weight sensor with a microcontroller? It ...
1
vote
2answers
257 views

How to switch both AC and DC voltage to a load

I have a load, an electrode basically acting as a very tiny capacitance, that I want to supply a voltage or bring to ground. The voltage can be either DC, up to about mains voltage, or AC into low KHz ...
1
vote
1answer
366 views

charging battery while under load

my question applies to NiCd/NiMh battery types. Can I simultaneously charge & discharge the battery? Might it cause any harm to it? I presume there will be opposite movements of the charged ...
2
votes
1answer
262 views

Boost converter can't power load. What are the limitations?

I'm trying to power a nixie lamp with a 9 volt battery. The boost converter charges up to 160vdc, the nixie lights, but quickly goes out (or half lights) as it pulls more current ~= 5mA. My boost ...
6
votes
2answers
193 views

Voltage regulator misbehaves under certain conditions

Okay guys, this one has me baffled. Take these two circuits: Typical stuff; Power in goes to the + rail, GND to the - rail. This is a 19V power supply going in. It goes through the voltage ...
0
votes
2answers
208 views

Simulate Headphone Load

I'm working on a low power (portable) audio mixing console, fed by audio signals from MP3-Players and mobile phones. There should be an option to monitor the sound, but as soon as I route one sound ...
1
vote
1answer
327 views

LT3080 regulator question

The datasheet of the LT3080 voltage regulator says that "For true zero voltage output operation, this 1mA load current must be returned to a negative supply voltage." What exactly does this mean? How ...
6
votes
3answers
1k views

Help needed optimising simple current limiting circuit

I have been experimenting with simulating current limiting circuits. I am trying to limit current to ~500mA given a fixed 4.8V source. I have started using a circuit like the one found on this ...
11
votes
2answers
4k views

Constant current, constant power and constant impedance loads

Ive been looking for information on constant power, constant current and constant impedance/resistance loads, there's some information about the constant current loads, but very little that really ...
1
vote
2answers
157 views

Different design in relay load connections

(I know, relay are drawn in the wrong way, NO contacts should be in serie with load, I'll fix it ASAP) When I have to build a board to switch many devices (mains powered), I always use a single ...
7
votes
2answers
282 views

Is this normal Buck Regulator behaviour?

I recently got around to trying out buck regulators, my results weren't what I was expecting though. For one the ripple voltage seems a little high to me, It's about 800mV with no load and goes up to ...
0
votes
0answers
570 views

Power Amplifier for Signal Generator

I am trying to find the operate power amplifier to solve my power needs, I basically have a Function Generator -> Power Amplifier -> Helmholtz Coil Now I am trying to figure out if I get the ...
2
votes
1answer
351 views

FEM: How to calculate impedance in stator circuit for loaded generator

I am modeling a synchronous generator and in the stator circuit consisting of 3 phases at the alternator output, I have resistances and inductances of the end windings. Thus I have a 3D approximation ...
0
votes
1answer
167 views

Circuit for switching higher load using transitor with signal being 300 Hz PWM

EDIT: DO NOT even think about using the naive example of a circuit to switch three phase. As someone rightly pointed out this is a complex issue and will almost certainly result in burnt finger or ...
2
votes
5answers
892 views

Hand crank DC generator - a simple dummy load that won't burn out?

I'm working on a project that allows a user to crank a hand generator while current and voltage sensors measure the output. After the user finishes cranking, software displays information about how ...
2
votes
2answers
1k views

How to calculate suitable dummy load for a power-supply?

A beginner question - feel free to shoot me down I'm looking to modify a retired AT SMPS to drive my ham-radio. This is to be achieved by tying all the +12V wires together so the maximum amperage may ...
2
votes
2answers
219 views

What loading capacitor do I use for my crystal?

I am using this crystal (the 7.3728 MHz variant). The datasheet specifies a 5pF to 55pF load capacitance; is this really so? I was under the impression that most quartz crystals had an optimal ...