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H: Op amp voltage regulator using N-Mosfet
I am trying to make a voltage regulator using an op-amp and a MOSFET:
schematic http://no4nwo.com/images/724278393.png
I'm really new to electronics. Why is \$V_{DS}\$ always so low ?
AI: Connect the inverting input to the MOSFET source /output - that's the first thing. Also ... |
H: Controlling multiple triacs with microcontroller for light dimming: where to use optoisolators
I want to control (dim) multiple mains lights using triacs and a microcontroller. (One triac per light). I want to keep both the costs and component count as low as possible.
Is it necessary to have multiple optoisolators... |
H: Generate sine wave in VHDL, with the use of 10-bits DAC
I want to generate a sine wave with 20Mhz frequency, using a FPGA (Cyclone 3 EP3C10E) and an external 10bit DAC converter (http://www.analog.com/static/imported-files/data_sheets/AD7533.pdf).
I have a vague idea that DDS or Cordic algorithm will work, but I do... |
H: How to protect my power supply output?
I want to protect my power supply ouput and I know that there are foldback solutions suggested by LM723 circuits, but I'd like to understand what is happening inside the circuits.
Consider the simple concept in the circuit below. I used a simple resistor to protect my output. ... |
H: Open-drain microcontoller ports
I want to understand the concept of open-drain ports like port P0 of the 8051 microcontroller. Why do we need to connect pull up resistors to the port P0?
I have basic knowledge of MOSFETs and other electronic devices.
AI: Ignoring the ins and outs of how mosfets work. The output ac... |
H: Extremely Cheap Geeky Code System
I'm hoping to create a really geeky 'capture-the-flag'-style checkpoint event. The goal is as follows:
Team A goes to Checkpoint 1 and, using some kind of device, scans a chip left at Checkpoint 1 or some code on a piece of paper to spit out a code.
Team B, at the same checkpoint ... |
H: Source and sink current
If I am connecting ICs to both sides of a led matrix, the ICs need to be able to source and sink enough current to light the LEDs? Or just sink?
Let me explain my question with an example:
In this diagram, I select which row is illuminated on LED1 through IC12 (a shift register). The column... |
H: check resistance is bigger then a constant?
As a part of a bigger project, I want to build an high resistance detector that will respond with a logical pulse
0- under 50KΩ
1- more then 50KΩ
what would be the most power efficient way of doing it?
I thought about using this one some how, but I'm stuck here.
AI: If y... |
H: Good high-gain amp chip
In a previous question, I asked about an audio-induction loop, and how I would amplify it. I am wondering what chip I should use to drive a 8 ohm speaker and what the circuit would look like. I mentioned the tl082,(an op-amp I have a lot of) but that didn't seem to delver enough power. I wa... |
H: Slow clock edge causing issues with D flip flop behavior
I'm trying to use a D flip flop and a pushbutton as a simple switch. My goal is this: every time I press the button, the output of the FF will switch state.
I put a circuit together in a simulator and it worked fine. I implemented a debounce circuit for the... |
H: When is it appropriate to galvanically isolate components/subsytems?
As the question implies, how do you determine when it is appropriate to galvanically isolate parts of the same electrical system from one another?
For example, I'm currently constructing a tube amplifier that has a significant amount of digital el... |
H: Current mode PWM Controller
I'm analyzing a power supply design. A Current mode PWM controller is used to step down the i/p 45-57 V/350 mA to 5 V/3 A. The design uses this part, http://datasheets.maximintegrated.com/en/ds/MAX5974E-MAX5974F.pdf
I read the datasheet but I couldn't understand, how exactly the stepping... |
H: voltage divider before inverting opamp
simulate this circuit – Schematic created using CircuitLab
I am taking a -8 volt signal and using a resistor divider to make it -3 volts by using a 16.5k ohm resistor as r1 and 10k as r2. I am feeding the -3v into a single supply opamp (+5 and gnd) in the inverting configurat... |
H: How can I modify this circuit for a higher gain?
Here is an image of an amplifier circuit.
How can I modify this for a 10-50 times more gain. I put a wire from pin 1 to 8, but I didn't get enough gain.
AI: Leave pin 1 to 8 open. Add another gain stage ahead of the LM386.
simulate this circuit – Schematic created u... |
H: Why don't more devices incorporate full-wave rectifiers as reverse polarity protection?
Recently, I was introduced to the idea of using a full-wave rectifier, in order to protect against reverse polarity damage in DC devices.
I hadn't even considered using a rectifier in an already DC circuit, but now that I think... |
H: What actually is the output current of a boost conveter?
What I understood at least at a basic level the operation boost converter, the inductor supplies output current when the switch is OFF.
When the switch is ON the the load current is taken current by the output capacitor.
Update
Is the classification of ... |
H: unable to understand write policy in Cache memory
I am studying write policies in cache memory ( for first time ). I am able to understand the 'write-through' but i am not able to understand 'write back' and the problems associated with it . Please can anyone explain me the 'write-back' concept clearly .
AI: In a w... |
H: Resistive sensor reading ADC
I have to make an ADC conversion with an ATXmega MCU, in an air quality application.
The input is a voltage divider between a voltage reference. The sensing resistor vary in relation to a gas concentration. I read the voltage between a load resistor and ground. Since the conversion is ... |
H: How do I read the markings on a Mitsuba capacitor?
I'm trying to identify a suitable replacement capacitor for use in a relay. The relay is by Mitsuba and uses a Mitsuba capacitor, which appears to print different notation on it than I have found in guides or SE questions so far.
My guess is this is a 3uF capacitor... |
H: What is reference voltage in a D/A converter
When I searched on the internet what I got as an answer for the above question is that the reference voltage means the highest voltage tha D/A can output.
But my lecturer at college did a calculation as below.
An 6 bit A/D has values 110101.
Reference voltage is 0.25V... |
H: what happens in a seperately excited DC generator when load increased
A book about electrical machines states as below
what happens in a generator of this sort when the load is increased? When
the load supplied by the generator is increased, IL (and therefore IA) increases. As
the armature current increases, the lA... |
H: Is this a polarised capacitor
So I went to a local electronics retailer, Communica in Cape Town yesterday. I had a small shopping list including:
10x 10µF Ceramic Capacitor
10x 0.1µF Ceramic Capacitor
The vendor didn't have any unpolarised capacitors, so he gave me the ones, as in the photo attached.
I immediate... |
H: How to create EMI?
I want to subject my product to large amounts of EMI to see what happens.
I figure I need the EMI to be broad-spectrum to be sure it will have the best chance of wreaking havoc.
However, I don't have any specialized equipment for generating or even measuring EMI, so what are some cheap ways I can... |
H: Why is my audio amp picking up AM and FM radio stations?
I built an audio amp out of the LM386 on a previous question. I when I have nothing connected, I picked up FM radio stations, as well as AM Very loud and clear. Why is this happening? Why AM and FM?
How can I prevent this? Although it is very cool that I pick... |
H: Is there a prebuilt PCB that does the equivalent of a wall wart for a similar price?
I am working on a project, and I need to convert 240V AC power to 5V DC to power a microprocessor. I can't use a wall wart, and I am looking for a PCB that will do the same as one - for near the same price. Everything I have found ... |
H: Bidirectional level shifter circuit problem
Ok, so here is my problem:
I am trying to create a small 3.3V to 5V signal level shifter, using a BSS138 transistor.
This is my source for the circuit: a SparkFun circuit.
This is my circuit:
As you can see, I have one bidirectional and one unidirectional line. On the le... |
H: Calculating battery life of Arduino + XBee Project
How do I calculate battery life of Arduino and XBee project?
Here's my information:
Battery's voltage: 3.6, capacity: 780 mAH
Current draw of Arduino + XBee when sleeping = 28,5 mA
Current draw of Arduino + XBee when wake up + transmitting data = 66,6 mA
I have s... |
H: Can a designer get hold of the PCI Express specification without being a member of the PCI SIG group?
I want to get hold of the PCI Express specification which is available here
. But when I try to download it, it asks me to login as a member - which requires membership at $3000 per year.
Is it possible to get hold... |
H: What's a simpler way to switch between power sources?
I want to make a device that allows the user to switch between two different power sources (a wall mount and batteries).
I could perform this circuit using two DPDT switches, but I would need to switch the two switches each time I want to change sources. Is the... |
H: Why would a modern digital clock rely on mains frequency?
I am in the military, stationed in Djibouti, Africa. We generate 240V/50Hz power on base, but some buildings also have 120V outlets, which I assume is transformed somewhere else on base, probably at the diesel generating station. I also assume that it is 5... |
H: How can I effectively reduce the voltage needed to activate a transistor?
I have built a circuit which basically connects the line out (audio output) of a music playing device to a set of LEDs (actually a huge strip of around 200 LEDs), so they flash in time with the music (from internet tutorials - I'm a bit of be... |
H: How do I verify if a conductive mat is getting "Earthed"
Explaining to me about electricity is like explaining to your Grand-Ma about it. So please be kind and gentle :)
I bought an Earthing Mat from "http://www.amazon.com/dp/B003RLOBOK". It includes a conductive mat to which I connect a white-wire whose other end ... |
H: Reading signals in a car 9-14.5v and translating to arduino HIGH / LOW
I have a project that requires me to trigger certain events in an Arduino based on certain electronic devices in the car being switched on and off. I essentially need to read a 12v HIGH state in the car as a 5v high state via an Arduino, but as ... |
H: Safety Relay Coil resistance
I have a Dold Safety relay OA5621OA5621 data sheet on page 2 of the data sheet it lists standard variants:
I have a 24 volt relay, OA5621.52 with 2NO/2NC contacts. I can't figure out what Rsp means, is it the contact resistance or coil resistance?
I need to find the coil resistance, is ... |
H: AQZ204 Solid state relay
I have an AQZ204 AC/DC type solid state relay AQZA204 datasheet
I'm using 31.5 volt DC supply, with a series 4.7k Ohm Resistor to the input LED of the relay.
The data sheet is a little confusing to me, it saids the LED max dropout voltage is 1.5V so I calculated around 6.38mA forward curren... |
H: Transformer for Flyback power supply
I am designing an isolated DC-DC converter with an input of 12V and an output of 5V@12A, at the moment, a flyback seems like the best option. I have read several books regarding the subject and I am proceeding to the implementation; however, I haven't been able to find a transfo... |
H: UART is garbled when running at more than 9600 bps
I'm connecting 2 MSP430F5529-based boards (running at 1 MHz) using UART and MAX3232 (MSP430F5529 -> MAX3232 -> cable, a few cm long - will be longer in our final application -> MAX3232 -> MSP430F5529).
It works as long as the bit rate of the UART is under 9600 bps.... |
H: Post-Transformer RMS Voltage for This Circuit?
I am confused here. For the below circuit:
simulate this circuit – Schematic created using CircuitLab
Ripple voltage is given as 1V peak to peak, Vo = 15V DC. I have assumed a 0.7V drop across any given diode. Please note that I was a little hasty in my construction. ... |
H: PMBus licensing
I have just (20 mins ago) started looking at the possibility of using PMBus in future products and have come across the PowerOne licensing issue (referenced by electronicdesign.com), but also other info that says the bus is an open technology...
I am unclear as to who exactly needs to license to use... |
H: Using a transistor to add to max current output from a opamp?
I thought I understood transistors but now I'm confused again.
I have a basic opamp circuit to amplify the input of a electret microphone. The output of the opamp will vary within 1-4V. Now I want to connect this output to a load (laser) and this modula... |
H: LEDs conduct in reverse direction!
In my circuit, I have the L1 ~ L8 LED as indicator LEDs on the even number pins of my header. TEST rail is connected to a +5V rail which can be turn on or off depending whether I want the indicator LEDs to turn on or off (the problem described below exists in both configurations).... |
H: How do I 'scope a mains appliance?
I am trying to study the operation of a single plate Induction Hob.
I wanted to use an oscilloscope to measure some of the low voltage digital signals on the microcontroller inside. So I attached the ground lead of the 'scope to a pin labelled 'GND'.
But when I powered up the ho... |
H: Digitally Switching a Single Source into 128 Channels
I have a device I'm building that uses a single high-precision current source (driven by a DAC for various arbitrary waveforms) to drive one of 128 channels. The current level will be on the order of 20uA
Building 128 redundant current sources is expensive and u... |
H: Switch and Pushbutton Combo
In a circuit I'm designing I want the user to be able to switch the power off and on (with an SPST style switch), as well as depress a push-button (push-to-break) that will temporarily disable the power - effectively a reset button. Ideally I would like to combine these actions into the ... |
H: How is lithography actually used to "print" transistors?
In one of my classes, we skimmed over lithography, but mostly the optics side of things (the diffraction limit, liquid immersion to increase angle of incidence, etc).
One point that was never covered is how the light actually dopes the silicon, and creating ... |
H: How could I build a headphone stereo to mono converter?
I have a friend who is permanently deaf in one ear but has normal hearing ability in his other ear.
When he listens to music with headphones or earbuds, he can't hear one of the channels which degrades his listening experience.
I'd like to build him a compact ... |
H: How does this soil moisture sensor work?
I found information on how a capacitance moisture sensor works, but I couldn't find any information on how the following sensor works. What is the theory behind this sensor?
AI: A likely mechanism for the operation of the sensor is by creating a Galvanic Cell battery out of ... |
H: ARM Power/Exponential Function
I'm trying to code an exponential function for use on a PWM signal.
My question is, does anyone know how to do a power function on an ARM cortex-M (STM32F4 in this case, which has an FPU) microcontroller. Or would a taylor series approximation do the trick better.
I know this is quest... |
H: FIFO wrfull asserted when FIFO is not full
I have an issue with Altera FIFOs. It seems that the full signal wrfull gets asserted even when the FIFO is not full. My FIFOs are of size 8. The SignalTap traces below show the read levels of my FIFOs (rdlevel) as well as the wrfull signals:
What could explain that the w... |
H: What do the different cables of the RS232 cable mean?
I learned that the TTL-232R-3V3 cable that I bought to program my MCU has 6 differently colored ports. What do each mean and do they represent specific things?
AI: It should be one of those: http://www.ftdichip.com/Products/Cables.htm
Most likely: http://www.ftd... |
H: Are there strong but insulative screws?
Common through-hole power semiconductor devices, like TO-220 and TO-247, can be mounted to a heatsink by running a screw through the hole in the device. However, on TO-220 the hole is often electrically connected to one pins of the device. TO-247 often isolates the hole from ... |
H: Connecting my RS232 Cable to my NXP - LPC1313FBD48
I recently bought an LPC1313FBD48 Microcontroller and an FTDI TTL-232R-3V3 cable. How can I connect the cable to the MCU? I cannot fit the pins of the MCU into the ports of the cable.
Would I need copper wire to connect the cable ends to the pins of the mcu?
AI: T... |
H: Is it common for internal pull-up resistors to fail? or what would cause them to become intermittent?
I have a board based on an ASIC ARM Cortex-M3 that after months of work suddenly started to report spurious button presses. The ASIC is not our design, but a reputable company's.
The buttons schematic is given bel... |
H: How do I convert a signal of 3v to 2v to a signal of 0 to 5 v
I'm measuring input voltages between 2v and 3v (3v volts corresponds to a reading of 0 and 2v corresponds to a reading of 10,000) on the analogue in of my arduino. I would like to measure the voltage at the highest possible resolution of the arduinos A/D... |
H: Vias in a footprint using Eagle
I have a fairly complex footprint which I have created in Eagle. Particularly the complexity comes from the number of vias required for the footprint (this is an RF part). Initially I tried to drop the vias using the through hole pads as a replacement, but when I do this, it will n... |
H: Showing three functions with Decoder 3-8
I`m trying to show 3 function with 3-8 decoder with only OR gates.
The following functions are:
F1 = A'BC' + AB'C' + ABC
F2 = A'B'C' + A'BC
F3 = ABC + AB'C' + A'BC' + A'BC
so what I did is:
I need to know if I did it right or there is something wrong in my decoder.
AI: If... |
H: Thevenin equivalent of a circuit
I'm trying to solve this problem, and i seem to be unable to solve it, part of the reason being that the there is a dependent current source in here, so I can't find the Thevenin equivalent resistance and voltage, I did find out the Ix current value of 5 Amps tho.
simulate this cir... |
H: How to implement HD74HC32 (quadruple 2-input positive-OR gate)?
I'm struggling to implement the HD74HC32 (quadruple 2-input positive-OR gate) package:
My breadboard looks as following:
Notes:
1.8 volt power supply, sufficient according to the HD74HC32 datasheet
1A is located at the left bottom
Vcc connected to [... |
H: Most efficient way to convert 6 V to 5.5 V
My goal is to design a USB charger for my phone/tablet when I don't have access to the power grid. I've used a LM317 with a 12 V, 5 A·h SLA battery but it does not provide enough capacity due to the power dissipation of LM317:
$$(12~\mathrm{V} - 5.5~\mathrm{V}) \times 700... |
H: Can you turn on / off LEDs from a webpage (javascript) via a microcontroller (arduino)?
I would like to use an Arduino microcontroller (with whatever shield necessary) to control LEDs. My challenge is how to get users to interact with a javascript-driven webpage to send a signal to the microcontroller to blink an ... |
H: Finding the total energy of the network in steady state
i got a network below in steady state im trying to find the energy in the network by the capacitors and inductors.
simulate this circuit – Schematic created using CircuitLab
My attempt to the solution was:
1) i open circuited the capacitors, and short circuit... |
H: Can a speaker be damaged but not blown?
If one plays too loud of a sound through a speaker, it can blow - i.e. become visibly torn or stop working entirely. However is it possible that the loud sound will damage it partly and result in the speaker operating at a less loud level; can a speaker blow just a bit?
AI: S... |
H: Easiest & cheapest way to use embedded filesystem on SD card
I want to build a cheap, basic project which logs data to an SD card that can be removed and read using a normal card reader in a computer.
Requirements are fairly basic so performance is not critical but simple would be good to enable a smaller device.
W... |
H: Flyback transformer - ambiguous schematics and other issues
I'm currently using this schematic for a flyback transformer:
(source: eleccircuit.com)
As you can see, there's a big problem - neither the schematic, nor the website describing it, give the value of the capacitor. It says ".01", but gives no units.
http:... |
H: Powering a custom Arduino compatible - 5V regulator or no 5V regulator?
I'm building a custom Arduino compatible with an ATMEGA328P.
Would it be better to get a 5V power supply that plugs into the wall to power the project and gives me a barrel jack, then connect that directly to the uC, or should I instead use som... |
H: How to build a smart wall
I want to build a smart wall where people can touch a 2 sqft region of the wall and it will detect who touched it and which cell they touched. The wall itself is made of plywood and I have access to both sides. You can think of it like turning the wall into a giant board game, where I have... |
H: What is the RMS reverse voltage for diodes?
in The datasheet
1N4001 Vr RMS 35V
1N4007 Vr RMS 700V
What is the meaning of RMS reverse voltage?
AI: Clabbachio is correct for a sinewave and that is how the datasheet specifies the voltages. It is the peak voltage that should never be exceeded as this will breakdown... |
H: 16MHz Crystal with 2p load capacity: What load capacitors are necessary
I found a nice and cheap crystal on AliExpress which I want to use with my ATMEGA328 microcontroller.
Its load capacity is only 2pF. Normally I would say, that the 2 capacitors from the crystal to ground with 4pF should work fine. But isn't the... |
H: An ethernet PHY chip speed support
I found ENC28J60 Ethernet PHY chip.
The specifications say that the Physical Network Type is '10BASE-T' on the one hand, but on the other hand the data rate is '10 Mbit/s, 100 Mbit/s, 1000 Mbit/s'.
As far as I know, a 10BASE-T chip can not support a data rate of 1Gbit/s !
Moreover... |
H: Can I control a 12V motor from arduino using an H-bridge?
I want to control my 12 volt geared DC motor from my Arduino Uno. I want it to be able to rotate both directions as I'm intending to use it for a robot.
Can I use the L293NE H-bridge in this case? The following diagram shows the pin connections. For this... |
H: How to correctly manipulate the I/O pins of PIC chips?
I learned a concept that when changing bit value of PIC I/O pin, PC would first read the value of the I/O port, and change the value, and write the changed value to the register.
I validate this argument by using this circuit:
The code I wrote in mikroC for P... |
H: Understanding rc time constant
I get that if you put a resistor in series with a capacitor and add DC voltage, the cap will take longer to charge up.
How can I calculate, how long it takes for the capacitor to charge up/discharge with the given capacitance and resistance and how can I calculate the voltage at a gi... |
H: How are electronic musical greeting cards made?
I remember that long time ago, when I was a kid (in the 80s) there was some electronic greeting cards that when open up, start playing simple tunes through a small piezo-electric speaker.
A quick look at the board reveal a small black chip and some circuits under:
I... |
H: Cascade DACs to get higher resolution
I got a RAM-DAC with 3 channels and 6 bits for each channel. The device in question seems very straightforward to use with a modern MPU like an AVR.
The resolution is a bit low, so I thought about cascading the three channels with a R-2R-ladder. Does that work with current-outp... |
H: what is Tau in this very simple circuit?
\$\tau = RC = 100 \cdot 22nF \$
or \$1000 \cdot 22nF\$? or should I add both the resistors together?
AI: After a "long time" the capacitor will charge to a voltage that is slightly less than 12V. This voltage is approximately 10.909V and this value is determined solely by t... |
H: Changing the orientation of the capactior in a simple integrating op amp
How does the terminal relationship i=c(dv/dt) change if you switch the orientation of a capacitor from +/- to -/+.
Here is the "normal" model that I have been studying.
simulate this circuit – Schematic created using CircuitLab
Here is the ... |
H: How can I check input of USB?
I have following wire as shown below, one end has male USB connector and other end has four wires. I know, when connected to laptop, the RED one acts as voltage source and BLACK as ground. If I give 2 bits data input to GREEN and YELLOW one, is there any software or API for (Python, C ... |
H: How to translate Change in Duty Cycle?
Morning!
I have a sensor, output of which is change in Duty Cycle of current. Now, this sensor is to be used with a MCU.
My knowledge of sensors with change in duty cycle as output is limited. So,i have the following question:
Would the change in Duty Cycle of current trans... |
H: How do I configure a external RTC that uses 3-wire SPI for the LPC 2387?
Here is the link to the datasheet of the RTC PT7C4302.
I can do it with MISO, MOSI, but SISO I have no idea how to do. Some similar code examples would be great.
AI: You need to tie the MOSI and MISO lines together and follow the protocol in t... |
H: Interfacing TinyAVR with bluetooth and passing message
I'm looking into interfacing the TinyAVR micro controller (not sure which one will work yet) with a Bluetooth module either the CC2540 or the nRF8001. I want to have the TinyAVR micro controller use the Bluetooth module to send out a small message like 0xf for ... |
H: Are Data Cards simply L1 (Physical Layer) Devices?
I was just wondering, how many levels of the TCP/IP (OSI) Stack reside within a modem or a 3G data card and other similar networking devices?
These devices do have a physical (MAC) address, which indicates that they have a Data Link MAC sub-layer, but what about LL... |
H: Widely available IC for encording and Decoding DTMF data
I am planning to do some research in data transmission over the air. For this I am interested in DTMF encoding and decoding.
Is there a widely available IC to achieve this? A circuit diagram using the same ic would be a better answer. An arduino solution wou... |
H: What is asked by this question re cache memory?
I've a difficulty understanding what is asked by this questions:
Can you explain in more detail? AFAIK the associativity determines the number of sets and the size of the set determines the number of bits that is not the tag. Is that correct? Then the block size dete... |
H: 8:1 Multiplexer With 5 Parameters of F(A,B,C,D,E) = ABCD +B'CDE+BC'D'
I am trying to create a multiplexer 8:1 with 5 parameters of the function $$F(A,B,C,D,E) = ABCD +B'CDE+BC'D'$$
what I did its to right it as minterms so what I get is:
$$ F = ABCDE + ABCDE' + AB'CDE + A'B'CDE + ABC'D'E' + A'BC'D'E \rightarrow m(3... |
H: What is In-circuit debugger and In system programmer
On many boards I have found that there is a circuitry called In-circuit debugger and In system programmer. What are these and how they are related to JTAG? I understand JTAG is also a kind of hardware debugger. Shall appreciate if someone can enlighten me.
AI: IS... |
H: How is "Overtemperature shutdown/protection" implemented for ICs?
IC data sheets often give some informations about the circuits over-temperature protection. Lets take a Microchip LDO (MCP1702) for example:
"...If the power dissipation within the LDO is excessive, the internal junction temperature will rise above t... |
H: How to connect sensor to PC?
I have made a sensor that produces a 4 bit output. I want to perform some logic based on patterns.
I was thinking if somehow I could give that 4 bit input to my computer, I could then write code to perform logic. But, the problem is, I have no idea how to do this.
How can I give a 4 bi... |
H: MOSFET as a voltage controlled resistor
This question might be too localized, but I try.
Is it possible to replace a variable resistor by a MOSFET, under conditions shown in the following schematic?
If yes, can someone propose a MOSFET type or the required MOSFET parameters.
simulate this circuit – Schematic creat... |
H: What is the point of this MOSFET?
In the image above, could someone please tell me what the MOSFET is doing? From what I gather, it is there for switching between the VCC_in and the regulated voltage, in conjunction with the SDA and SCL lines. However, if all the components are receiving the regulated 3.3V from th... |
H: Need a protection diode if only connected by common ground?
I have many solenoids running on 25VDC. Some are controlled by MOSFETs which are powered by a 5VDC circuit, and others are controlled by physical switches in the 25V lines. The 5V and 25V circuits have a common ground. I put protection diodes on the sole... |
H: Working of a GPS
one of my friends is thinking of a startup in which we will use GPS technology . The thing is we are thinking of making a cheap gps receiver indigeneously but i am not able to find good links on the internet regarding the in-depth electronic working of the GPS receiver . I have understood the conce... |
H: Relay Protection (Mechanical)
In what ways can a Hobbyist with Electronics extend the life of a mechanical relay and overall make it safer to use?
Or is it really not worth it as in Damage it going to occur regardless? Maybe using a Capacitor or something to store charge and let it drain out naturally? or is this n... |
H: How to determine Frequency response in BJT
What do I want to look for on a BJT datasheet to find out the maximum operating frequency before distortion occurs? Or perhaps the question should be: How do I know how fast a transistor can cause the main current to change in response to a change in the base signal curre... |
H: Designing a synchronous counter with d flip flops
I have to design a counter with two inputs: x and y. If y = 0, the counter behaves like a 3-bit ring counter, and if y = 1, it behaves as a 3-bit Johnson counter. If x = 0, it counts up, and if x = 1, it counts down. I may only use D flip flops, and any logic gates ... |
H: Netduino or Raspberry PI for my requirements?
I do not want to start a religious war, and believe that neither of them can be better in all circumstances. So, let' consider my circumstances.
My problem is that I am a software guy with no knowledge of hardware and Google is not my friend today, so I hope that I can ... |
H: State Diagram Issue - Equivalent Situations
How do I know according to the following diagram if I have a equivalent situations, how do I recognize it?
for example we will examine S2 and S3.
I would like to get an advice how to do it.
Thanks!
AI: Just check if there are states where:
Outputs are the same for all ... |
H: Li-poiy battery charge hold over time
I am developing a driver for a Li-Poly battery. This is the first time I am dealing with such battery. Does these types of battery always rise to the maximum voltage of 4.1 (based on the datasheet and measurement) even after several charge discharge? i.e. after 500 times.
I kn... |
H: Whats the principle of a PLL used as demodulator of a FM signal?
I didnt quite understand te following:
A basic PLL consists of the following parts:
phase detector
low pass filter
VCO
If you input a 1MHz sine the PLL will try to lock on it by controlling the VCO. According to what i've found it's possible to demo... |
H: How to realise bidirectional ports in FSMC function of STM32?
I am using FSMC(Flexible static memory controller) function of STM32:reference manual.On page 494 of referencec manual, the data bus should be bidirectional. It is reasonable but i have no idea how to realise it in STM32 because it has only two modes: in... |
H: Rectifying induced current without using any semiconductors
Consider a 1:1 transformer.
Short DC pulses are applied to the primary (input) coil. Once it's positive current pulse, once it's negative current. It's not strict alternating current (i.e. two successive positive pulses are possible). I want to block negat... |
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