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H: Confusion regarding Fixed-Biased configuration of JFET
This is the picture of a fixed-biased JFET, taken from a book :-
This is written in the book, relating to the above pic :-
I am unable to understand why \$ V_{GS} \$ has a different polarity than \$ V_{GG} \$ in the first place. Shouldn't they be of the same ... |
H: Darlington array: How to output desired voltage at uln2803a driver colectors?
Someone suggested this driver array to get the current I need:
datasheet
I also need a 12V signal and about a current of 100mA in order to control a relay coil. My 12V signal would come from a logic gate that will provide a current of I =... |
H: What is the formula for calculating the no load current of a 3-phase motor?
I am looking for the formula, not a rule of thumb. Is there a way to calculate the no-load current?
AI: As both Andy aka and Bimpelrekkie have commented, there is no useful formula because there are far too many variables both known and unk... |
H: TTL to NIM logic translation Logic Gate Issue
NIM is a standard used in nuclear physics. I'm facing an issue with a logic gate being used in my TTL to NIM translation circuit, and I'm not sure what is entirely wrong with it. For a little background, I'm trying to replicate a TTL to NIM logic translation circuit as ... |
H: Relationship between voltage and current of a power transformer
I'm currently analyzing data from a power transformer and I stumble over the circumstance that voltage and current is almost not related to each other. Since I'm not an engineer I wonder why is this?
From my knowledge, the voltage must drop when curren... |
H: Periodic timer not working as expected on TM4C123 MCU
I am starting to learn how to use timers/interrupts on the TM4C123 evaluation board (TM4C123GH6PM MCU).
In this example I am configuring a timer to create 1 second delays to toggle an on-board LED on and off. But when I run the code in real time on the board, th... |
H: Problem with 4-SMD Crystal / PIC16F1575
I'm trying to work with 32Mhz 4-SMD Crystal. (ASX3F-32M-FA100A4) with two capacitors: 10 pF (attached datasheet)
The IC I choosed is the PIC16f1575. And using MPLABX-IDE MCC
I performed the connection as in the pictures below.
When I select INTOSC in MCC everythings works fin... |
H: Meaning of (*(__IO uint16_t*)PAGE0_BASE_ADDRESS) variable declaration
There is a variable declaration:
uint16_t status = (*(__IO uint16_t*)PAGE0_BASE_ADDRESS);
__IO is the precompiler directive that becomes the keyword volatile. PAGE0_BASE_ADDRESS is the hex address, say 0x08000000;
I can't get my head around what... |
H: If I am discharging a battery at 30% of its energy and then charging it at 0.8C. How long will it take to be completely charged?
Suppose that I have a lead acid battery that:
Can (and will) be discharged by using 70% of its energy (energy left is 30%)
When the battery is at 30%, I will recharge it at 0.8C.
How l... |
H: How do I find an ADC circuit's bandwidth experimentally?
I'm trying to measure the bandwidth of a circuit that I've built. It's an analogue-to-digital converter (ADC) with some input protection and biasing. The ADC samples at a constant/fixed 50 kSa/s.
My approach is to inject a 2 V sine wave of variable frequency ... |
H: Transistor pad layout for efficient use of prober
As we are a materials company the expertise is not in EE, so I am asking a very simple question. I tried to search online for this, but could not find an answer. We are making transistors with our special materials and need to put many on a test chip. Hooking eac... |
H: ESD Protection diode polarity
I'm using the following ESD protection diode:
On the datasheet it says:
MOUNTING POSITION: Any
Does it mean I can assemble it at any polarity?
(switch cathode and anode connections)
AI: Yes. Bidirectional ESD/TVS are agnostic to mounting position because either way presents exactly ... |
H: Help identifying tantalum capacitor marked E105
I am trying to repair a device that was handed to me. It has a broken tantalum capacitor with a missing lead, so it needs replacement. However I'm having trouble identifying its capacitance, voltage etc. I believe it's a KEMET T494 series but I can't say for sure. The... |
H: XADC Current Sensing Reference Design
Please refer to this reference design for AC701 (snippet below).
The schematics, specifically the current sensing sections in pages 34-36, show this:
I want to understand why, for the REF output of INA333, there is a pull-up of 0.05V?
AI: I want to understand why, for the REF ... |
H: Footprint unclear part
I am trying to draw a footprint of some component which has 8 pins but in the document they shared for outline dimensions and footprint:
Outline dimensions
Footprint
There is some rectangle in the middle of the footprint. That has sx and sy dimensions. That part confused my mind. Is it silksc... |
H: Why is the Digital 0 not 0V in computer systems?
I'm taking a computer system design course and my professor told us that in digital systems, the conventional voltages used to denote a digital 0 and a digital 1 have changed over the years.
Apparently, back in the 80s, 5 V was used as a 'high' and 1 V was used to de... |
H: Measuring the activation time of a solenoid
I'm trying to measure the activation time of a pull-type solenoid.
When the solenoid doesn't have a load connected to it, you can measure its activation time through the current it consumes.
At first, the solenoid will consume current until the magnetic field is strong en... |
H: Does an oscilloscope subtract voltages as phasors?
I want to measure two voltages on an oscilloscope. They are not in phase. I want to know the magnitude of the voltage difference. The oscilloscope has an in-build math function to subtract the voltages from each other. But does it do that phasor wise ? Let us say V... |
H: Connecting and disconnecting the power supply
I have learned that powering a chip without ground is quite dangerous and might cause permanent damage to the chip or the board in general. I have also seen that happening many times in non isolated DC to DC step down converters and some microcontrollers as well.
How ca... |
H: Two-stages class AB amplifier
I'm studying the following two-stages class AB amplifier:
Basically it is a standard two-stages op-amp (i.e. the cascade of a differential pair with active current mirror followed by an inverter with active load) to which the source follower M8-M9 has been added in order to provide th... |
H: Xilinx FPGA, error creating generated clock
I just got a Digilent Basys 3 board (Artix-7 FPGA) and I am trying to create a program to transmit data over the UART-USB connection. I wrote a module but when I tried to implement it I got a timing error. I have been using the standard 100 Mhz clock which comes with th... |
H: How many ground and power pins to have in a connector?
I'm designing a daughter board for a project. There are 35 I/O pins that need to go to the board. How do I determine the number of ground and power pins to include? How do I determine the placement of those pins throughout the connector?
I know something like t... |
H: Is it possible to boost current into a load without boosting voltage also?
If a device "D" requires X watts power, and I have a power source Y that is less than the nominal voltage recommended by the device "D", can I obtain the same performance for the device by somehow boosting the current such that Y·(boosted cu... |
H: TypeMatrix keyboard connector type
I'm trying to investigate problem in my type matrix keyboard and I have two questions
how is called that connector (what type is it) on the right, it has around 25 pins +/- 2 pins?
Is it possible to read what is inside that chip on the left or debug that somehow?
Br,
bioky
AI:... |
H: Area under voltage vs time discharge curve
Will the area under a voltage vs. time graph of a battery discharge curve (with a constant current load) give the amp-hour capacity rating of the battery?
AI: No, in your case it is not the area that tells you the capacity, but the length of time before the voltage is so l... |
H: Notation on schematic for circuit with n-channel switch
I am designing a circuit with a load that will consume up to 2A @ 5V. I decided to use a slide switch rated at 100mAh to drive an N-channel MOSFET for the (relatively) high current, since a slide switch rated for 2A is significantly bulkier.
I understand that ... |
H: Sampling frequency and FFT
I have tried this example code for sampling and FFT in MATLAB, but I have noticed that when the signal frequency becomes closer to nyquist frequency , some errors ( small frequency components near the given signal frequencies ) in the frequency domain begin to show up. Is there any explan... |
H: How to break apart grooved PCB
I recently got a set of 20 breakout PCBs. I didn't realize that they came in one piece- that they had not been cut apart yet. However, there are grooves between each board that are cut into the material. The grooves extend about 1/3 of the thickness through on each side, leaving about... |
H: current mirror biasing cascode
Guys My doubt is that for the following cascode configuration how can the minimum voltage needed at the drain of M1 be Vt + 2 Vov for M1 and M2 to be in saturation ?? Vov is the over drive voltage whihc is Vgs- Vt.
For saturation considering that Vds > Vov. At transistor M1 the minimu... |
H: How to interpret Vcc and GND on integrated circuits?
I am a little confused about power supply markings on ICs. For example, if I have an IC named U1 stating that Vcc should be 5V, can I connect it this way:
simulate this circuit – Schematic created using CircuitLab
Or this way:
simulate this circuit
Or this way:... |
H: OP-AMP Output Voltage
In the below schematic,
Photodiode is used ( not diode)
OP-AMP OPA 380
So, Vo = If X Rf
Case1:
IPh= A , Rf= 10K, VCC pin =5V
Vout = A X Rf = A(10K)
Case2:
IPh= A , Rf= 10K, VCC pin =3V
Vout = A X Rf = A(10K)
Does it means, Vout will be irrespective of VCC voltage?
Thank you in advance.
AI: Ye... |
H: Additional Resistor For Pierce Oscillator
I want to build SIM Card Reader by following a schematic from here as follow:
I realized that the clock generator (upper center) form a Pierce oscillator but with an additional resistor (R2 symbol in the schematic), which different than Pierce Oscillator circuit at wikiped... |
H: LTSpice Full Wave Controlled Rectifier Erronous SCR Breakover
I'm attempting to simulate a full wave SCR rectifier:
However it is not behaving correctly. In my setup V3 controls one pair of SCRs, and V4 controls the other. All the math on the side is just for setting up the pulses that control the gates. The first... |
H: UART Receiver Sampling Rate
I am trying to create a UART receiver in Verilog for my FPGA. I was following this guide http://www.fpga4fun.com/SerialInterface4.html
According to it the standard practice for asynchronous communication is to oversample the signal at 16 times the BAUD rate. This makes sense to me sinc... |
H: How do you rewrite a transfer function to standard form?
How can I rewrite a transfer function in terms of resonance frequency \$\omega_0\$ and damping factor Q? Referred to as "standard form" in the university materials.
I'm still at it, trying to understand LCL filters, and found a gap in the university material.... |
H: why my power calculation for this resistor is wrong?
i encountered a very simple question in a test and i easily calculated the answer
but somehow i am making a mistake because i can not find my answer between the available answers, what am i doing wrong ?
thanks.
Question : Calculate the wasted power on the 6 ohm ... |
H: Error when passing wire of different size to module input
I have a module to display a base 10 number on my 7-Segment display.
module displayN(input [13:0] n, input clk, input [3:0] an, input [6:0] seg);
wire [3:0] d1 = n % 10;
wire [3:0] d2 = (n / 10) % 10;
wire [3:0] d3 = (n / 100) % 10;
wire [3:... |
H: Is it safe for babies to use any kind of battery for a wearable project?
I want to make a wearable project for babies, is the commercial batteries safe for babies? Lithium Battery or Alkaline AA Battery? or can be risk to use them? the current provide by the batteries can harm the baby?
AI: You can, just be careful... |
H: Can't find CD4050 library in Proteus 8?
I am using this schematic as a frequency meter. I tried to search proteus libraries for this CMOS 'CD4050 , [IC3 in this schematic]' but all I've found is 4050 CMOS non-inverting buffer with one input and one ouput, I need this specific element with all the other pins of it, ... |
H: Reversing a small synchronous gearmotor
it's been difficult to find the answer to this problem I have. My project is based on home automation.
I need to control the direction of the rotation and if possible the torque of an AC synchronous motor like this one with the Raspberry Pi 2, to close and open curtains.
The... |
H: power supply independent biasing
In the current mirror given below
I can see that the Iref produced strongly depends on Vdd whihc is the supply.
In the diag shown below which is power supply independent as they call it,
I do not understand how this is power supply independent. The PMOS M3 and M4 anre supply depen... |
H: Is here a node missing when using the node voltage method?
I am currently learning the Node voltage method to get a better know how about circuits. Let's say you have the following circuit:
This is the workout example with all the nodes. IMHO, I disagree, I think there is one node missing and the circuit should be... |
H: Confusion in interpreting NPN transistor's saturation region
Above screen-shot is from a SPICE simulation of an NPN BJT where it shows the output characteristics Vce versus Ic. Ib is kept constant at 5uA where Vce increased from 0V to 5V.
I'm having difficulty in interpreting this plot at the saturation region. Ok... |
H: Current in a branch containing both resistor inductor?
simulate this circuit – Schematic created using CircuitLab
There is a switch in the circuit which has been closed recently so the circuit is now in transient state and we are applying KCL at node 1.
Also we cannot use Laplace transform.
Is there a method for ... |
H: Why voltage drops when I short a battery?
When I short an AA battery, I have observed that it's voltage drops a couple hundred millivolts and when I break the short, its voltage starts to "replenish" at a decreasing speed.
What is the reason for this behavior?
AI: Actually, if you are truly shorting the battery, th... |
H: LCD Interfacing types
I am learning LCD interfacing and came across parallel, RGB, LVDS interface so far.
I have worked on parallel 8/16 bit interface.
But have few doubts in overall interfacing of LCD.
Is RGB a parallel interface?
For TFT's with RGB pins, do we always need LCD controller to take care of all LCD c... |
H: Using a PAL for a seven segment display
I know next to nothing about PAL. I was wondering how one goes about programming a PAL (an old TIBPAL 16L8-25CN in my case) to drive a seven segment display, sort of like a HEF4511B. Right now I just have an arduino uno and a raspberry pi, do I have to buy an EPROM programmer... |
H: Manual SPI device select
From another stackexchange question it should be possible to have the SPI device select pin always asserted given that the SPI bus only has one slave.
I have other interesting features multiplexed to my SPI device select master, so I would like to get rid of the connection altogether and c... |
H: Given the current and voltage of a consumer electronic device, how to calculate its power draw?
Given a device that uses electricity from the wall socket (220-240V AC@50Hz or 110V AC@60HZ), and it has its current draw specific (i.e 1A), how can I calculate the power (in watts) that it consumes?
I know that for DC c... |
H: How does a coaxial aerial cable work?
My family and I managed to break the aerial cable of our TV a few days ago.
The cable is of this kind of design:
And I believe its called a coaxial cable.
Fortunately, someone more practical than me has fixed the cable, but it made me wonder: how do these cables work?
The pers... |
H: Would a transistor be the correct device?
I am going to create the following circuits. However I need to be able to have a switch that completes the lightbulb circuit when VM1 input > 4.3v
I think a transistor may be the answer from what I have read. Please could someone give me some help. I have thought about usin... |
H: Power Consumption on 220VAC vs 120VAC
I have an appliance that consumes 5mA when in standby on 220VAC mains. I'm assuming on a 120VAC 60Hz system it would also consume 5mA in standby (can't measure it). Since I haven't measured it, I guess my first question should be: Is the appliance likely to also require the ... |
H: How plausible is the claim about a 200 kW battery solution?
Following this question posted on Aviation:SE:
Does the ARCA hoverboard violate known limits on small-diameter electric fans?
which is related to a hovering board described on the vendor site:
(source)
I would like to assess the claim this device really... |
H: 3-dB Frequency of second order transfer function
How can i obtain the 3db frequency of the each transfer function ?
My attempt:
My guess is both transfer functions have the same 3db frequency.But equating the magnitude to 0.707 gives a fourth order equation which can be reduced to second order to obtain square of ... |
H: Why should we use LED driver chips instead of much simpler structures?
For example: I have two led driver chips: bcr321u and RT8474AGSP
And think they both support to same output voltage and same output current etc. My question is about topological differences of them. BCR321U is definetely looks simpler and it i... |
H: Programming/Verifying EPROMS with an elevated VCC
Many EPROM manufacturers specify a faster programming algorithm which involves temporarily raising VCC from 5V to about 6V.
If I read with this higher VCC in place, are the outputs still limited to the 5V vcc, or does my reading circuitry need to be 6V tolerant? Si... |
H: Why is the output (in the truth table) inverted in a ic 74154 used as a demux?
I am studying Digital Principles and Applications from Malvino and Leach. I have a doubt in the demultiplexer section. This is the image of a 1 to 16 demux. I understand how it works.
So, if ABCD = 0000 and STROBE = L and DATA = H, then... |
H: Analyzing BJT differential pair with feedback
I have an exam next week, and I need to get a real high mark to pass. Therefore I'm looking for some hard questions to solve, and this is one.
While I don't expect a full solution from you here, some guidance would be nice.
What does “assuming B of the BJTs is very hi... |
H: Need safe power supplies for beginner class with indicator light
In an intro electronics class in high schools, we use 6v battery packs as a way of delivering safe power for experimenting. However, the logistics of constantly getting fresh batteries, and our distaste for using so many batteries is leading to a sea... |
H: How to drive 1080p with only 540 pins?
I was trying to hack a 3-D system starting from the monitor: VG248QE.
I teared it down to LCD matrix and driver. This is a 1080p(1920 x 1080) monitor so I was expecting that at least 1080(row) + 1920(columnn) = 2000 pins wired from the LCD driver to the LCD Matrix(I am not cou... |
H: Help me identify this audio connector on a turntable
I have recently purchased a West German NECKERMAN 830 record player (1960s), which requires a separate set of speakers for audio output. Could somebody tell me the technical name for this cable so that I can purchase the correct counterpart?
AI: It appears to be ... |
H: Can a resistor start a fire?
I read that if you create a short-circuit, this produces heat and can cause a fire or damage an electronic component. The solution is to use a resistor.
The heat generated by electricity is proportional with the amount of
electricity passing through a conductor in a period of time
... |
H: Transient simulation in Cadance
I have been trying to do a transient simulation of a Power supply independent biasing circuit in Cadance but how much ever I try I do not see the transition of the states. I always get only the steady state even if I put the stop time in nano seconds ! This is the circuit that I am t... |
H: What standards or conventions are there for BOM line items for non-refdes parts?
Some designs have parts that may lack a reference designator because they never appear on the schematic. Examples include:
Battery holders
PCB-mounted (soldered on) fasteners such as solder-nuts
IC sockets
Jumper wires on a single si... |
H: BEC or CEB NPN Transistor
I am looking for a small, inexpensive NPN transistor, similar to 2N4401 in specs, with a BEC or CEB pinout.
Does anyone know of any?
AI: that's an RF pinout, "TO92-3" eg fairchild KSP10 |
H: Is this something a P.L.C. would be able to do?
I wish to replace the zener diodes with a programmable chip, so that I can program the chip to do exactly what the zener diodes do in this circuit. This will then make the circuit universal to all my applications, and all I would need to do is reprogram the chip to us... |
H: Transmitting PWM binary at 400kbps (or 800kbps)
I need to send a string of bits to a chained set of RGB LEDs, each of which have their own controller IC. The datasheet for that IC, the WS2811, is here.
The protocol is quite simple: each bit, both 1 and 0, are sent as a high and a low, with different mark-space rati... |
H: Why do you have to use the nominal voltage of the transformer for the no-load or open-circuit test?
I was wondering why exactly you have to use the nominal voltage of the transformer for the open-circuit or no-load test. Is this also the voltage over the parallel elements, even in a situation where the transormer i... |
H: Burning Intel Microcontroller using AVR programmer
Is it possible to load hex file created to Intel 8051 micro controller using AVR USBISP programmer
This is the Datasheet..
http://pdf.datasheetcatalog.com/datasheet/Intel/mXqzvzz.pdf
AI: The datasheet confirms my suspicions : you don't program these, using AVR or ... |
H: plugging battery against the power supply
This may come across as a rather nonsensical question however I think it is worth asking simply to understand what happened.
I plugged in an electric car battery directly to a wall socket, almost immediately there was a significant explosion in the wall socket. There was a... |
H: get many different signals through one wire
I am new here. I want something done, and I strongly believe there is an IC for this job, but I don't know what it is called and I can't get the right words into google. What I want is to take many electrical signals and have them pulse in a single file line, sort of to s... |
H: Is it possible to use a potentiometer as a DP3T style control?
I'll try to be specific:
I have an audio application that has 3 inputs and 1 output. The classic answer would be to use a DP3T to switch between the inputs. However, I would like to have a continuously variable output, one that blends as you sweep a... |
H: Basic Nmos amplifier working
I am trying to understand this circuit here.
I do not understand clearly how this works. I know that the PMOS is a current source but what impact does the resistor Rb have on this ? Could anyone help me out with its working ?
AI: Rb is biasing the NMOS into saturation (a good thing).
... |
H: Designing a gate voltage for N-channel MOSFETS for H-bridge controller
We have a project where our 2nd year students build an H-bridge controller from scratch. They learn a lot about power dissipation. We have a simplified design using IRF540 for the N-channel, IRF9540 for the P channel. These are way over-spec ... |
H: 10 USB Hub ICs from 1 Crystal Oscillator?
I am designing a PCB with 10 individual USB hub ICs onboard. They all require a clock input and I am wondering if it is possible to drive all the clocks from a single crystal oscillator?
The hub IC is http://www.ti.com/lit/ds/symlink/tusb4020bi.pdf
AI: Yes, you can -- take ... |
H: Transistor with emitter attached to another transistor's base
I made a circuit that looks something like this:
simulate this circuit – Schematic created using CircuitLab
If I touch the loose wire with my finger, the LED will light up. Could someone explain what is going on? Is there a specific name for this effect... |
H: Power Electronics
I am currently building a wireless charger. I have difficulty in understanding the working of the regulator (7805) to which I connect the load and measure my output power.
My power receiver circuit schematic is like this
LC circuit(receives power from transmitter circuit) -> Rectifier(converts ... |
H: Oscilloscope measuring different voltages "across" the components when two probes are used
I'm having problems displaying two channels simultaneously on an oscilloscope when both probes are connected to measure voltages "across" the components.
To demonstrate the problem two resistors are connected in series and fe... |
H: Connect 12V digital LED strip to Arduino
How to connect a T12V-10L-30LED-W LED strip to an Arduino?
Here is the strip specification.
And here the actual image of the strip:
The package says:
VCC: RED
GND: WHITE
DAT: GREEN
My question now is: Does the DAT input take 12V or something else? And how to wire this wit... |
H: Raspberry PI audio over Cat5e wired ancient hotel intercom
My question is can I (and how might I with minimal insanity) connect the audio output of a Raspberry PI (and/or other USB audio outputs) via say some 10-30m of Cat5 cable to some 10 or so pretty ancient looking hotel room speaker units, which might have am... |
H: Verilog: Are there some basic rules for port settings?
Iam trying to write a SPI master module by myself to learn FPGA-Verilog efficiently. Here is the spi_master module:
module spi_master(
output [15:0] tx_data,
input [15:0] rx_data,
output mosi,
input miso,
output cs,
... |
H: Working principles of an LDR Light Switch
This is a simple circuit which dims the LED according to the light recieved by the LDR or simply a light switch.
Can anybody explain how two BJTs opearete in the circuit, or simply how the system works?
AI: Assuming everything is biased reasonably, ...
More current through... |
H: USB protocol PIC32mx
I am adapting a design using a PIC32MX (which is actually working) to put an extra add-on. The add-on is a fingerprint reader which communicates via UART. Regarding that I have the USB pins exposed in my design, I found a way to connect a ftdi 3.3V (https://www.sparkfun.com/products/9716) betwe... |
H: Can I connect the negative terminals together on two LED drivers?
I have a white, adjustable-color-temperature LED strip that I'm trying to power. The LED is basically composed of two separate LED circuits -- one at 6500K and another at 2700K. The strip has one positive lead for each circuit and a shared negative l... |
H: UART is acting weird
I programmed UART3 peripheral on LPC4088 to send a single unsigned character posiljka over Tx line. This is done by continuously copying this character into the Transmitter Holding Register (THR) which is the top of the transmitter FIFO.
So I connected my oscilloscope to the Tx line and tried ... |
H: How to get more watts from a 1W amplifier?
I'm a newbie in the world of electronics, and I decided to build a 3 watt amplifier.
I searched arround the web and I found the following schematic for a 1W amplifier:
(source: hackaweek.com)
Note: Put a 2k resistor in between the ground and the emmiter if you want to pre... |
H: Normalizing audio signal for ADC input
What is the best way to limit an audio signal for ADC input (to 0V - 3.3V) with out disrupting it harmonically? Ideally, I'd like the conditioned signal entering the ADC to be a signal uniformly spanning 0V to 3.3V. That is, I'd like to strip the original signal of its envelo... |
H: Texas instruments C1101 RF1100 module Schematics
does anyone got schematic from this module. I tried searching around but didn't get anything except main header pin-out. There are also 2x2 pin on each corner, but there is no info about them.
AI: If you look closely, you see the four small copper lines that connect ... |
H: Wiring identical LEDs in parallel
I am working on a project in which I am powering several 20 ma LEDs off of a 12 volt supply. I therefore need a 470 ohm resistor. The only problem is I don't know how many LEDs I will need. I know that powering say, 4 leds in parallel off of one resistor is a bad idea because of po... |
H: connect 2 speakers to act as a telephone
I've got this very faint memory from my childhood that my dad connected 2 pieces of old, 5 cm diameter speakers to each other with a 10 meter wire. And without any other equipment, it would transmit the sound between rooms. Not loud or anything, but volume was enough to hear... |
H: How to connect TPA7297 S-GND and PW-GND
I've just started making an amplifier for some speakers and I'm completely new to this and couldn't find any information in the documentation explaining it. So I just wanted to know if S-GND and PW-GND can be connected to a common ground back to the negative battery terminal?... |
H: Best method/circuit for converting 240VAC to 5VDC (Low power)
In short, I'd like to power Arduino-like devices (small PIC devices as well) run off of a mains socket at 240VAC - which obviously can't be done with a simple wire. I assume I'd need an output anywhere between 3 and 5 volts DC.
I don't want to use a gene... |
H: How to combine two chip enable(/CE) signals into one with discrete components?
My VIC-20 has a few bank select lines that are used for enabling ROM chips on the cartridge port. When one of them goes low, it means that a certain 8KB region of the address space has been accessed.
Usually you can hook these up direct... |
H: 3V7 to 5V level conversion
In my product i am using a wifi module requires 3.3v and a bunch of other components requires 5v. For this i am using 3.7v 3000mAh battery. So here i have a doubt whether to use which case or any other suggestions
case 1: To use two 3.7v battery in series becomes 7.4 so that i can use a 3... |
H: How to filter out ringing current in a local battery telephone system?
We have a network of manually-switched local-battery telephones. Here is depiction of the circuit in one telephone:
Ü transformer
OB local battery (1.5 V)
GU hook switch
F speaker
M microphone
Ind magneto (30–100 V, 15–30 Hz)
W ... |
H: Atmega basic circuit with or without crystal
I want to build a basic Atmega8a (DIP-28) micro-controller circuit (programed using a 10 pin ISP socket).
I have found several basic circuits. Some of them use crystal oscillator, some use internal oscillator.
1- What options we have when it comes to oscillator? (differe... |
H: How to power a circuit that needs +9VDC, GND, -9VDC?
While I have an assortment of 5V, 9V, 12V wall-warts, but I don't remember ever seeing one that is 18VDC and trying to avoid a trip to specialized parts shop, since I have all other components of a circuit (of a microphone mixer) that I am building.
Here is the c... |
H: 555 timer circuit power consumption
My goal is to have an LED flash (rather than stay on all of the time) in order to conserve battery life. So, I learned how to modify a 555 timer circuit so that the LED flashes for about 0.1Hz and remains off for ~10 seconds.
The circuit diagram is like this:
Source: http://ww... |
H: Questions about FM Mic Kit Schematic
I'm currently building an FM Microphone kit and I'd like to understand its operation before physically putting it together. The documentation only provides an overview of some aspects and provides no calculations or insight into the selection of component values.
Am I correct i... |
H: Calculate voltage and current in time dependent circuit
I'm working with this time dependent circuit, and i'm having troubles with some of the assignments.
The following values are given R1 = 1kΩ, R2 = 2kΩ, R3 = 1kΩ, C1 = 22uF and C2 = 47uF. Is delivers 20mA, and when t=0 the switch goes from connected to disconnec... |
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