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Passive components are not capable of power gain. This could include resistors, capacitors, inductors, diodes etc.

-1
votes
2answers
104 views

Detect 230VAC or 12VDC in the same pin [closed]

I'm designing an input interface for a microcontroller (uC). Want to detect signals (only want to know if there is voltage or not) of different typology, so you can have in the same input to the board:...
0
votes
3answers
79 views

Square wave to DC voltage with passive components

Good day, I have a design challenge that I have been thinking about. Is there a passive and inexpensive system that I can get a square wave (frequency not decided yet, but less than 8MHz) that will ...
14
votes
8answers
3k views

Why, in a passive circuit with a sinusoidal input, do all voltages and currents have the same sinusoidal behavior as the input?

I am familiar that in any circuit composed of linear passive elements and a sinusoidal input, all voltages and currents through and across any element will exhibit the same sinusoidal behavior and ...
3
votes
1answer
116 views

What is this small white component across transformer's inputs/outputs?

I was tearing apart a transformer that was not working (from halogen lamps) and I found this little thing inside: Eventually I found out it was a bad connection that made the transformer faulty and ...
12
votes
3answers
1k views

High speed passive probe - contradiction between authors or different points of view?

In a document Hiscocks et al. describes some basics of Oscilloscope probe theory. The document is very understandable and seems coherent. Notice in particular that for him, the bad guy is the parallel ...
1
vote
0answers
196 views

How to identify a dead potentiometer?

So, I've cracked open my Roland Micro Cube which is a portable 2W guitar amplifier with digital modelling. The issue I've had with it since recently is the tone control potentiometer. Here's a picture ...
0
votes
2answers
79 views

Resistor ladder network component name

Very basic question I'm sure I am trying to buy components for a project I am doing, but I cant get the name of a component right yet. But it has to exist somewhere. I want a resistor array but ...
2
votes
3answers
303 views

Resistor Power Rating and headroom for AC circuit

Background I'm going to put together a resistive load, to load a 100W source with an \$8\Omega\$ or \$16\Omega\$ resistor. I'm finding that when to use peak, peak-to-peak or RMS values of voltage, ...
3
votes
2answers
102 views

1 pulse toggle with simple non programmable electronics

I need to create a simple circuit that toggles when one pulses a push button and then stays on no matter what you do with the push button again. The toggle will reset when the system is powered off (...
-1
votes
3answers
77 views

Replacement for Linear Potentiometer

A rotary encoder replaces a rotary potentiometer, while providing a long live due to no wiper degrading the substrate. How can I replace a linear potentiometer (a "fader") with something following ...
0
votes
1answer
107 views

What are these components in green white and orange colour on this PCB?

Got curious about these components because they seem very different from what I've used till now.
1
vote
2answers
61 views

Interscatter technology

For anyone familiar with interscatter technology: Can a single device (smartphone) be used to generate the bluetooth packet and receive the wi-fi signal? From the paper it looks like you need a ...
0
votes
0answers
39 views

MEMS or other modern component electroscopes

I was looking for a component-style electroscope. I thought, "Surely there must be some MEMS-based electroscopes capable of 2- or 3-significant-figure potential measurements." But the only thing ...
0
votes
2answers
175 views

Passively Buffer Voltage

I am working on a project where I would like to use a single pole rotary switch as a mode switch, but also provide power to the MCU. By providing the common on the switch with 3V, I can identify what ...
1
vote
0answers
111 views

What is the official name of this item?

I have purchased this item locally in the past and basically its 5 wires aligned in parallel, and makes my circuitry much easier (eliminates the needs to manually connect 5 individual wires side-by-...
0
votes
1answer
44 views

“node” which can hold different values to be read by a sensor? [closed]

I have a question about sensors which are able to read values of specific "nodes". The "nodes" in my context are like little metallic materials which can be placed somewhere i.e. within a flat wooden ...
3
votes
2answers
756 views

Modeling passive elements at high frequencies

It is well-known that any electrical passive element (Resistor, Capacitor,Inductor) contains parasitics that usually manifest themselves at high frequency ranges of operation. For example, a resistor ...
3
votes
1answer
542 views

Is there a passive component able to stabilize current (as zeners can do with voltage)?

So I need a component which will have a flat сurrent–voltage characteristic (constant current in a wide voltage range). Initially I was intended to ask a general question: what kind of the device can ...
2
votes
2answers
236 views

Identify this component?

I refer to the two round yellow-ochre things mounted on the blue capacitors. They are coupled in series from a sold-state power amplifier stage, and the capacitors AC couple to the speaker load. The ...
0
votes
1answer
114 views

Passive components swapping and replacement

I am trying to writte a small note for our staff when they purchase components. Quite often some resistors, capacitor, inductor, diode and transistor (NPN and MOSFTET) may not be availble on the ...
3
votes
4answers
646 views

Selecting passive components [closed]

I am in the case where I read a lot of datasheet and I quite often see some circuit where the chip manufacturer indicate some value for resistors and capacitor but by not indicating any part number, ...
0
votes
2answers
107 views

Wiring a membrane potentiometer to give two outputs

I'm using a softpot membrane potentiometer in a project and I have found that pressing two fingers on the strip gives strange results. I was expecting it to short to the lower resistance value but in ...
-2
votes
1answer
69 views

How to calculate the needed order of a LPF?

I am new to filters and am asked to calculated a lot of things for a passive (Butterworth and Chebyshev )LPF. The very first thing asked is to determine the needed order LPF for these specifications: ...
-2
votes
1answer
144 views

is there a way to light up the second led and not the first one? [closed]

simulate this circuit – Schematic created using CircuitLab In this schematic I made I'm trying to light up a a series of LED's but not in sequence "not yet" what I want is to raise the start of ...
-5
votes
3answers
336 views

how can we make a signal out of a 2 pin mic output

ok im looking to make this type of setup so that i can use its output pin to read via analog. this is the mic i got and would like to make that 3rd pinout which as you can see it only has 2 and this ...
-3
votes
1answer
62 views

what type of modification can i use in my MCU in conjunction with my SSC32? [closed]

Hello there guys im looking for a way to connect and use a DC motor with a Servo controller such as the SSC32? now given the fact that a Servo controller or driver has 3 pins, PWR GND SIG/PULSE now ...
20
votes
2answers
2k views

What is the dual of a diode?

A diode has an exponential I-V curve. To a first approximation, it will pass whatever amount of current is required to keep the voltage across it constant. Is there a passive component that will (...
2
votes
5answers
315 views

Human touch pins on MCU (atmega328p) directly or other components needed?

I would use atmega328p to read the pulses transferred in human's body. So I wonder if that's good to directly expose the pins of the chip. Or there should be some type of components for protection and ...
1
vote
2answers
121 views

Is there a typical 'ferrite' for use in a PCB?

I have a circuit diagram that I am trying to replicate (actually the Teensy 3.0/3.1 circuit diagram shown here https://www.pjrc.com/teensy/schematic.html) and there is a component called simply '...
2
votes
2answers
791 views

Detecting Specific PWM Signal Without Programming (Only Electronics Components)

I want to detect a specific PWM signal by electronic circuit components i.e. transistors, opamps, capacitors. update: I want to build simple ID system. I want to detect specific PWM signal for example ...
11
votes
4answers
5k views

Ceramic (MLCC) versus Tantalum capacitors

From the perspective of an electronics designer, but also taking into account price/cost and social considerations (see Coltan mining and ethics link below), I tend to avoid Tantalum capacitors under ...
0
votes
2answers
112 views

Why can't passive components transform energy from one form to another [closed]

In parts of electrical components active components can control the flow of current in a circuit but passive components cannot. What is the factor that gives active components the ability to control ...
30
votes
2answers
6k views

A PCB for a Drone

I'm making a drone, and would love if somebody can review my work on the PCB layout. Image (red is top, blue is bottom, circles indicate holes and side transfers purple is glue): What is supposed to ...
0
votes
1answer
865 views

A circuit that does multiplication of two signals when some scaling down is OK

Suppose one wishes to multiply two voltage or current signals, which may not be completely DC. It is OK for the product to be scaled down in order to avoid the use of transistors and complicating the ...
0
votes
1answer
96 views

Active and Passive Filter

How does the transfer function of a filter change if I change it form active to passive keeping the order and cutoff frequencies unchanged?
5
votes
2answers
244 views

Why is this a 7th order circuit?

This is the circuit: I saw it in a book. It said that this is a 7th order circuit. From theory we know that the order of linear passive circuits is determined by the sum of capacitors and inductors, ...
0
votes
3answers
325 views

Inductance of toroidal-cylindrical inductor?

If the inductance of a solenoid is \$L_{\text{sol}}=\frac{\mu N^2 A}{l}\$ and the inductance of a toroid is \$L_{\text{tor}}=\frac{\mu N^2 r^2}{D}\$, is it correct to assume that the inductance of a "...
1
vote
2answers
126 views

What is that rotating component for menu?

On some home made electronic circuits, to navigate the menu on LCD screen, a rotating component is used. My first guess was that it was a potentiometer and ADC was used for detection, but it rotates ...
1
vote
1answer
441 views

Reducing the voltage into a speaker passively

Well not high power, low resistance. I have an unusual situation where I am directly driving speakers from an oscillating signal ( its not audio its more like a buzz ) I only have 2 inputs 12v ...
1
vote
1answer
354 views

Size of inductors in passive filters

I was reading about why we need active filters even when we have passive filters with us. I got to know that one of the main reasons for doing so, is that at lower frequencies the size of the inductor ...
4
votes
4answers
6k views

How to inverse behaviour of a switch?

I have a sustain pedal (which is just a momentary switch!) with the wrong polarity (according to the device I'm using it with) : circuit is CLOSED when pedal is pressed circuit is OPEN when pedal is ...
-2
votes
1answer
181 views

What to expect when i place a diode in magnetic field

I am designing a PCB that senses basic NTC values and converts it into digital format. The problem is the entire PCB is above a magnet(about 70mT at the board) that is moving. Hence i want to know ...
0
votes
1answer
95 views

How can I make an optical circulator? [closed]

I need to a single mode 1550 optical circulator at my lab. I have a varied supply of components, but no circulator. Any idea how I can make one myself? Perhaps using coupler and isolator? Thanks. -D
12
votes
6answers
3k views

Other than cost, is there a reason to not use higher rated components than called for by design?

(Apologies upfront if this question seems too vague, I'm trying to formulate the problem statement as I ask this) I'm thinking about circuit assembly in a high component variability / low MOQ ...
4
votes
3answers
653 views

LC lowpass filter optimization

I have some 12 volt cooling fans which interfere with a radio transmitter. I notice that if I either put a large capacitor in parallel, or a large inductor in series, I can eliminate the noise heard ...
2
votes
2answers
565 views

Pass DC through (passive) highpass filter?

Background: I'm a student, working on my final year project. I am designing a front end for a software defined radio. We have an IF frequency at 36Mz (and a BW ~8MHz). We are bandpass sampling this ...
0
votes
1answer
2k views

What is this inductor-like part?

In a laser printer's power supply board I have desoldered some of these passives. I think it is a inductor, because it's legs aren't exactly aligned and the round body could be the coil. Does ...
16
votes
10answers
5k views

Schematics for a simple radio transmitter that can be built only with passive components?

Fantasized in some of the survivalist, post-catastrophic novels, movies or docudramas is the radio built only with handcrafted or scraped components. Beyond the popular appeal of this stories, I ...
2
votes
6answers
3k views

Electronic flasher with low load detection

The circuit above is an existing flasher without low load detection. I am trying to develop electronic 2-wheeler flasher with low load detection. While Googling, I got a circuit with relay in it, one ...
2
votes
1answer
981 views

Why are SMD Diodes different Packages than Resistors and Capacitors?

I was looking for SMD Schottky Diodes on Digikey, and they all come in weird packages like SOD-123. There were some that were 1206 or 0805, but they seem fairly rare. Why is this? The only difference ...