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H: RGB LED Strip - several question from newbie
I've just bought 5 meters long 12V analog RGB LED strip and I'd like to turn it on!
There're 60 LEDs per meter so, totally 300 LEDs and each LED consumes 20mA.
Here're my questions.
From internet guide like this(https://learn.adafruit.com/rgb-led-strips/usage), power is... |
H: PIC16F57 - problem implementing wake up signal on key stroke
I have designed a simple RC5 remote control using a PIC16F57 and the classic rows-columns scan over a 4x4 matrix keypad.
The previous version of my firmware continuously scanned the keypad to find a keystroke but the batteries consumption was to high (obv... |
H: Systems and signals - integration with dirac's function and step function
I'm taking the introductory course to systems and signals and the mathematics of integration using the step function and Dirac's function
and
For the first integral, I just don't know how to deal with u(t-4), the step function.
The other t... |
H: Temperature stabilization with PWM , PID controller with delay system
I am doing a project to control the temperature with PWM. I use peltier, thermistor,mcu and h-bridge mosfet.
I want to reach a temperature with an error less than 0.05 and stay at that temperature without much (at most 0.05 C) oscillation. My fi... |
H: when to use auto correlation and when to use fourier transform
In communication, if we don't know any prior information about the signal, we perform an auto correlation say Rx(T) and take the Fourier transform of Rx(T) to analyze the power spectrum.
Supposing if my signal is known do i need to perform auto correla... |
H: What is the purpose of a capacitor in the feedback path of a unity gain buffer?
First time using this site, I'm an EE student and have been studying opamps. So far in class we have only discussed 'ideal' opamps, but I saw an opamp with this layout and was wondering if anyone could clarify what 'C1' and 'R1' are us... |
H: How to up-convert PWM frequency without using a microcontroller?
I am trying to drive a motor H-bridge, but my control system can only support a 400 Hz PWM signal (black box, can't change it) which gives the motor an extremely loud 400 Hz whine as you would expect.
Is there any way to take the 400 Hz PWM signal and... |
H: SMPS: What is current mode instability (aka “sub-harmonic oscillation”)?
In peak current controlled switching power supplies, there is a phenomenon called “current mode instability” aka “sub-harmonic oscillation”. What is that? Can't seem to get a good explanation of this....
Bonus:
(To mitigate this side effect, t... |
H: Replacing capacitor from unworking TV with some other capatitors which has not the same value
I am repairing (trying to repair) my TV.
I found 1 capacitor 25V \$1500\mu\$F which i think is bad (it has some weird shape at top)
I don't have any capacitors with that value but I have some similar to that
25V \$470\m... |
H: Convert positive square wave to positive-negative
I am looking for a way to convert a square wave coming from a microcontroller with voltage range from 0V to 5V, to a voltage range from -12V to +12V. The frequency of a square wave will vary from few Hz to few MHz.
Thanks in advance!
AI: Use an op-amp, powered from ... |
H: Bike light blink speed adjustment
I am trying to construct a circuit to control an LED in a bike light kind of circuit. This circuit must be designed so that a button press can change the current setting of the light.
So for instance first click turns on the light on slow blinking, one more click goes to fast blink... |
H: Are those two filters equal?
Are those two filters equal to each other in their functionality? Of not, what is the difference between them mathematically speaking (zeros, poles, etc)? Also, what is the difference in their function?
Essentially I want to simplify the op-amp filter to something without active compone... |
H: 2-bit branch prediction accuracy
I am trying to solve this problem, the answer should be 15/20 = 75%.
However, I am not sure how this was calculated and want to understand the underlying concept.
A program core consists of five conditional branches. The program core will be executed thousands of times. Below are th... |
H: T-flip-flop without using a clock
Is it possible to create a T flip-flop without using a clock? I really need one, but I can't use one with a clock because it requires a signal shortener.
AI: You can just wire the toggle input to a high level and then your signal goes into the clock input, this way the output toggl... |
H: Replace 12V 5A power supply with battery
I am buying a rgb led strip with the following technical details:
Voltage: 12 volts
Wattage: 60 watts
I want to connect this strip to a battery and don't know what will be the right one. I need the battery to last for 2 hours.
I been doing research and this are my assumptio... |
H: How to measure coils without inductance measuring device?
I have a multimeter that can measure capacitance, resistancr, voltage and current.
If I have a known coil and unknown coil, can I measure the ratio between the inductance of the two coils?
Is it possible to determine the inductance of an unknown coil?
AI: Pl... |
H: Do logic families use different type of transistors?
Do the logic families such as TTL and CMOS represent only different logical structure? Or do they also use different type of transistors? Latest microprocessor chips with millions of components use CMOS. Is that only because CMOS "operating logic" is superior or ... |
H: How to find the expression for Vout?
I have that circuit and I need the equation of Vo, I've been told that I can solve it by the Kirchhoff method but I'm not sure.
Is there a way that the expression looks like Vo=K(V2-V1) ?
AI: Opamp circuits like this can be solved with a few assumptions:
1) The circuit is line... |
H: Can a transistor's emitter and collector be used interchangeably?
I'm trying to understand the standard TTL NAND Gate in TTL level.
But confused with the transistor Q1 operation in the diagram below:
Apparently when A and B are together HIGH, the Q1 base-emitter junction is reverse biased.
Collector-base junction... |
H: EAGLE PCB, how to specify an out-of-board component?
This might be a very basic question. I have a schematic where some of the components are outside of the board.
For example, for a power supply, I have a switch and a transformer that are on the schematic, but I want them to be placed outside of the PCB, for this ... |
H: How should this code look like in verilog?
I am designing an ALU to add at state 000, I have to assign control signals for a mux, carry in, and operands so that it works. so, i wrote an if statement in the controller module, and the TA told me that its not verilog, but I thought I saw a youtube video with verilog i... |
H: Why do they separate some parts of PCBs through making wide holes?
I have seen several PCB that they have wide holes in some their parts (especially the supply of circuits parts). for example take a look at this picture:
and on the board:
Not sure but I think it is related to the noise, Is it correct?
If so, it'... |
H: Physical significance of group delay
What is the physical significance of the group delay of a system/filter?. Why is the slope of the phase response critical in a communication system.
AI: As already pointed out in other answers, the group delay (at a certain frequency) is the delay of the envelope of a narrowband... |
H: LED that emits light in different direction
Is there such a thing as an LED that emits its light horizontally ("to the side") when mounted on a PCB instead of the ususal "up" direction? If so, what are these called, and do they use the same standardized footprints as normal LEDs (1206, 0805, etc.)?
AI: Yes, many, m... |
H: Voltage limiter with LM358
I have a problem with circuit, because I don't know how to design a voltage limiter.
I connect to the input (In) sensor that generates signals with range of 240mV to 940mV. Next, The signal output with sensor is amplified voltage by LM358 operational amplifier.
The maximum voltage outpu... |
H: Is it possible to design cascaded LC filters with inductors sharing the same core?
I want to design an higher order LC filter for filtering out a power signal. In the theoretical design, the inductors are supposed to be on separate cores. But in practice, it will be very costly and space consuming. Is it possible t... |
H: Can some pins of the same port on AVR MCU's be declared as inputs and some as outputs?
Can some pins of the same port of AVR MCU's be declared as inputs and some as outputs?
If yes, then I am not able to understand how this works since we have to compare the pins of the port and also assign the values to output pin... |
H: Low pass filter design with transimpedance and difference amplifiers
I have a DDS chip with complementary current outputs that I need to filter. I'm using a design like this:
I need a different cutoff frequency, however - 2 MHz instead of 50 kHz. Note that I'm not using the particular op amps specified in that sch... |
H: Inductor burning out in a GPS bias tee circuit
I've got a tracking device that uses a Telit GE864-GPS combined GSM/GPS module. The GPS antenna is connected to the Telit module via a bias tee circuit, as shown below:
http://upload.wikimedia.org/wikipedia/commons/6/6c/Bias_t.png
The RF only port is connected directly... |
H: Implementing High Pass Filter in Simulink
I am trying to implement the following block diagram using Simulink in Matlab.
I am having trouble getting the high pass filters to work properly.
To do the filtering, I am using the First and Second order filters from the SimScape toolbox.
Using a step source I am getting... |
H: Are there other ways in which 60Hz noise can get into your system?
Are there are other ways in which 60hz can get into a system other than ground loop ?
AI: Yeah lot's of ways.
Besides those already listed...
If there is a cylindrical inductor in the circuit. (loops can be other than in just the ground line.)
Ro... |
H: 2.5mm Jack to USB data Cable
I was recently diagnosed with Type 1 diabetes. With the need to test my own blood upwards of 8 times a day I have a ton of data to keep track of. My testing unit has the ability to upload its data to a mobile (OTG) or PC (USB).
Sadly, the company who makes the unit does not ship either ... |
H: What is cut-in voltage of a transistor?
Some literature talk about cut-in voltage but couldn't find a clear explanation.
AI: It's not an officially recognized term by any standards body, but in the south-eastern United States (and possibly elsewhere) "cut-in" (cut-on) is the colloquial opposite to "cut-off" (cut-ou... |
H: Purpose of T flip-flop in this circuit (LED)
In this circuit I try to toggle a LED on and off when a switch is pressed.
Given the nature of the T flip-flop, when the switch is triggered, it toggles the clock and since T=1 always, it essentially reverses the state of Q, so in other words, it toggles the LED on and ... |
H: Calculating gain of multiple antenna system
Some radars have thousands of antennas, there are also some routers that have multiple antenna systems.
But I want to know how to calculate total gain of multiple antennas in a system? Is it simply equal to the number of antennas times gain of one antenna?
What about beam... |
H: 4 iPad Air charging circuit indicator led not working
I developed this circuit in order for it to be connected to 4 ipads at the same time the current they use to charge when they are on low battery goes around 1.8Amps, That its working as intended, however the part that has the led indicator for a blown fuse ind... |
H: I need help with verilog code, I am in trouble?
I am basically setting different control signals for the ALU to perform operations in verilog. But I have tried all possible ways of writing what I want but in vain, can you help me out. How should I set these control signals at particular 3 bit alu states;
This is my... |
H: How can I use the presence or non-presence of an 120VAC input to actively discharge a bias power rail?
I'm designing a power supply that has an input of 100VAC to 300VAC. On the primary side on the main transformer, I have a 15V rail to power the control chip (a FAN6920) and a gate drive chip (a FAN7382). On this... |
H: LaunchPad development board talking to itself using a CAN bus
I have one Texas Instruments Tiva-C Series TM4C123GXL LaunchPad and two MCP2551 transceivers. I am trying to send and receive messages via a controller area network (CAN) bus. Is it possible to do this using only one LaunchPad?
AI: The TM4C123 has two CA... |
H: Circuit Protection re: Relay Coil
Is the flyback diode adequate protection in for the microcontroller in the following circuit?
simulate this circuit – Schematic created using CircuitLab
Will my circuit experience over voltage conditions on the 5V rail despite the flyback diode? My 5V is generated by a step-down s... |
H: What would make me choose Verilog or VHDL over schematic design on CPLDs or FPGAs?
I have absolutely no background in programmable logic, I use mostly microcontrollers in my projects but recently I needed to work with video and the microcontroller is just too slow for what I needed so I started playing with CPLDs.
... |
H: Electric field around tape
So, there's a tape with width of 2a, -a on the -y and a on the y, and it very long, penetrating the the plane of picture, it's charge density (dQ/dS) is
σ=σ0 * y /a , σ0 is a constant.
What is the electric field in point A(a.0)?
I tried solving this using charged disk, expressing electric... |
H: Get clean 9VDC power from 9VAC using a LM317T
I'm having trouble with this design, I have this circuit below, but I already have the 9vAC transformer, so I just need to convert the current to DC, so:
If I remove the Vadj part of the LM317T on the circuit below and keep everything else at it is, would that still kee... |
H: How to shorten fall time on high-side BJT drive?
I have built a PCB with a set of high-side BJT drives shown in the schematic below. I'm using 8 of these to drive the columns of an 8x8 RBG LED matrix.
While debugging the board with my oscilloscope (with the load, i.e. L1 and R4, disconnected), I noticed that the ... |
H: What happens if I supply 18V to a 12V lighted switch?
I am fairly inexperienced with electrical engineering and usually just wing small things I.E. a current project.
Basically I have a project box, with a 12v arming switch with a red light in it. Currently I do not have the momentary switch installed but those pa... |
H: Effects of C Rating on Battery Life
A polymer lithium ion battery is rated at 3.7v, 6600mAh and a maximum discharge current is specified at 3.3A. I take it this means the battery can be discharged at 3.3A and last for two hours since 6.6Ah/3.3A = 2 hours.
However, in addition to the above specifications, the batter... |
H: How can I bind a local variable to AVR's rXX register?
I need to have programmable pause with precision as high as possible. To accomplish this I have the following GCC code:
void delay(unsigned char d){
volatile unsigned char i=d;
while(i>0) i--;
}
Which is compiled to:
1cc: 89 81 ldd r24, Y+1 ... |
H: How can I render my 2.4GHz antenna directional?
With barely no knowledge in this field, I would like to render my antenna used with Bluetooth BLE devices more directional.
I tried to shield the antenna with different kind of metals with no luck.
Is there someone to point a way in order to render my antenna directio... |
H: Sending multiple channels with bluetooth
I have ordered my HC-05 BT modules. My question is this: Is it possible to send multiple channels over bluetooth. For example, stereo sound has two channels. I think i have seen people do this but i'm not sure.
If it is possible, could you please provide some more informatio... |
H: How do I solder to these pads?
Quick question. I'm trying solder some wires onto the 5 pads (top right of board) in the image. What's the best way to achieve this? I cant get the solder to stick to the board and I have no flux. I have to be careful because there's components on the other side.
I tried to use pin he... |
H: How to run a 6v 4amp motor at slower speeds for long periods of time (2 hrs)?
I am trying to get a project done for Halloween. I am running a 6V 4A motor (from a powerwheels) but need it to run slower. I tried using an adjustable charger and ran it at 3V to slow down the motor but it wasn't turning the motor beca... |
H: Are all sequential circuits based on cross-coupled NAND or NOR gates?
So far, all the sequential circuits I see in the textbook use cross-coupled NAND or NOR gates. Is it possible to design a sequential circuit without them?
AI: By sequential I assume you mean a (bit) storage cell?
A static storage cell must have ... |
H: Make Bypass with Switches
I have the diagram below, but I don't understand how the switches are hooked up. Is that an special switch, or I can achieve that with an special connection? Thank you!
AI: That's two switches connected together that can be in either of two positions. It is a DPDT (double-pole, double-thro... |
H: How to prevent applying power to I/O pins before BBB ready?
From the Beaglebone Black SRM Rev C.1: "DO NOT APPLY VOLTAGE TO ANY I/O PIN WHEN POWER IS NOT SUPPLIED TO THE BOARD. IT WILL DAMAGE THE PROCESSOR AND VOID THE WARRANTY.
NO PINS ARE TO BE DRIVEN UNTIL AFTER THE SYS_RESET LINE GOES HIGH."
I want to connect a... |
H: PCB trace width calculation
Take a look of this product: http://www.hobbyking.com/hobbyking/store/__68694__HK_Pilot_Power_VI_Module_Distribution_Board_And_Dual_UBEC_ALL_In_One_120A_and_10s_.html
It says is a 45 by 45 mm PCB, gold plated. It is just a power distribution board, two input pads where you solder the ba... |
H: A question on pull up resistors
I'm wondering why pull up resistors in text books are told such that they pull up the voltage to \$V_{CC}\$. Here is a diagram:
When the button is open what will be the input voltage to the micro controller? \$V_{CC}\$? No voltage drop at \$R_1\$?
AI: If the button is closed then th... |
H: Output of a NAND gate
Above is a TTL totem pole output NAND gate. There is a 120 ohm pull up resistor there. Since it is called pull up, can we say that the HI output will be connected to a very high input impedance? If so what can it be as an example? Aren't NAND gates in an IC are connected to each other by bein... |
H: Does a typical mobile adapter draw current when no load is attached?
Summary:
I am comparing the trade off of wasting my time daily plugging and unplugging multiple chargers at multiple sockets. I need to know approximately how much Amp is my adapter drawing every second when in no load (have not attached my mobil... |
H: Logic low not low enough
I'm having an issue where the "low" level being output from one device isn't low enough for the device on the other end to interpret it as such. I'm guessing I'm not the first person to have this problem, but I haven't been able to find a solution.
Here are the details:
I'm trying to interf... |
H: How are processors tested before going to production?
No matter how much experience an engineer has, or how many engineer works on the design of a processor or a microcontroller, we are human at the end, and it is possible to make mistakes. Before sending a processor design to production, how are they tested so the... |
H: +5v and -5v power
I'm building an analog switching circuit which is controlled by an arduino.
My circuit requires 25 4066 quad-analog switches.
To get the required analog voltage range for the switched inputs, I need to provide +5v and -5v input power to all 25 of the 4066's.
I have tried to use a 1044 charge pump... |
H: Interfacing switches with microcontroller
Im trying to interface momentary push-button switches to my Stellaris EK-LM4F120XL.
Im using a positive logic interface, to momentarily set pin as HIGH if the button is pressed. A 10K resistor is connected to GND from the switch, which is then connected to Vcc, 5V. The sele... |
H: Can I increase inductance using permanent magnet ?
I know that when I insert a ferromagnetic core inside an air-cored coil, the inductance increases.
What if I inserted a permanent magnet with a cylindrical shape into an air-cored coil, does the inductance increase or decrease or still constant ?
Is there any effec... |
H: Voltage wave form across a DC motor driven by a transistor with pwm
Above is the simple implementation for a DC motor control with pwm.
I was expecting to see a square wave with a Vmax when Q1 is ON and zero when Q1 is OFF like the one here:
standard pwm
But what I saw in oscilloscope is different. The OFF stag... |
H: How does an speaker amplifier have to be build for a given DAC output signal?
I am working on a project "cat projector" which shall "shout" at the cat when she jumps on the table in the living room.
For the logic I use an Arduino board which plays/streams the sound at 22.1kHz from a SD-Card and using the MCP4821 DA... |
H: LEDs in parallel, strange current consumption
I just wired a blue LED on a breadboard with the anode to an Arduino Uno's 3.3V rail and the cathode to a 220 ohm resistor to ground. Then I measured the current consumption using my Fluke 87-V and it was 1463 microamps.
Here's the strange part: I then added another blu... |
H: register without clk
I'm designing a small system in VHDL using the datapath and contorller method. Is it okay if I design registers that don't have a clock input (load data on the rising edge of the load signal) as they are being controlled by the control unit which is going to be running on the same clock signal;... |
H: Multiple voltages power suply, high current
I'm trying to design a battery back-up power supply for my home network devices. I need these:
48 V / 40 A
24 V / 10 A
12 V / 2.5 A
5 V / 5 A
I got a 48 V / 60 A industrial power supply with battery backup (four 12 V car batteries in series) and need to divide the volta... |
H: Will the current flow through the diode?
This question originates from a difficulty to understand fly-back diode current in DC motors.
In the above figure which logic is ok:
1) 9V-2V = 7V, so diode is reverse biased and current will not flow.
2) diode is applied 2 volts forward bias in a loop so current will flow ... |
H: How long does ultrasonic rangefinder last
I've built a parking sensor in my garage that uses the HC-SR04 ultrasonic rangefinder and an arduino to measure how far the car is from the back wall.
The one thing that I'm worried about is if the sensor will continue to work for a long time. When it senses an object, it... |
H: Is possible to use wave guide to decrease beam width?
If I use a normal 1/4 monopole antenna "30 MHz for example" and cover it with metallic wave guide has a narrow beam width, should the gain increasing according to this formula below?
$$G = 10 \; log \Big(\dfrac{32400}{H \times V}\Big)$$
AI: Rule of thumb: physic... |
H: Voltage standards? Like 3.3V, 5V etc
What exactly are the main voltage standards called for all the common voltages we see?
3.3V, 5V and 12V are some of the most common DC voltages but what are they known as exactly and what's with their significance? i.e. Were they picked as it sounded like a nice value or for an ... |
H: Diodes block voltage?
I understand the basics of a diode, a diode allows current to flow in only one direction, but how? By blocking any opposing voltages source so that no current can flow in opposition?
And of course, a diode has its limit. If there is a voltage in opposition that is higher to what the diode can ... |
H: voltage drop when using voltmeter
it's a theoretical question.
is there any voltage drop when measuring a 12v battery with a multimeter(voltmeter mode)?
so if we get 12 Volts reading near the battery, does this changes if we extends the cables of multimeter to 1 km ??
AI: A typical DMM has a very high (but not infi... |
H: Is there anything besides power factor that determines the max CFL that can be used in a socket compared to the max incandescent for that socket?
When shopping for lamps recently, I've noticed that the sticker on the socket says something along the lines of "To reduce risk of fire, use maximum 60 watt incandescent ... |
H: Why there are live and neutral wires attached to house's wall sockets
If AC voltage is alternative, why there are two (Suppose there is no earth wire) wires attached to the wall socket: live or hot, neutral wires? And I think that in small home generators there is no need to specify which wire is the live wire?
... |
H: High Power Supply over a distance
I'm working on a project and have been stopped in my tracks part way through.
I am designing a system that will power an RC over a distance. So I have a generator, and around 300 meters of cable to a low power system. Since I want to use lighter wires I plan on ramping my voltage v... |
H: Is the quoted range of an RF module based on two identical modules?
Take for example this 433MHz transceiver module. It's quoted range is 300m.
What does this value mean? Is this the distance when the signal strength dies down to 0%?
Does this mean if I were to buy two of these (one for transmit, other for receivin... |
H: Detect a missing PWM signal in the smallest possible board space
I have a motor control board that basically has zero space left, and the customer wants to add a fault flag to tell if their 2 kHz PWM input signal is lost.
So basically, I need to detect a lack of edges over a few milliseconds, using a small number o... |
H: ATMEGA328p ADC keeps returning 1023
I'm trying to configure my ATMEGA328p to measure temperature using the TMP36GZ temperature sensor. However, the 10-bit ADC keeps returning 1023. I've tried disconnecting the temperature sensor (it should return 0 at this point for the ADC reading), but it still returns 1023. I'm ... |
H: Creating Custom Component + Pattern - Diptrace
Right now I am creating the schematic and the final pcb layout of my circuit in Diptrace so that I can etch the PCB myself.
I am going to use LM2985-3.3 SMT LDO from Texas Instruments in my circuit to step down the 5V supply. This IC is available on SOT23-5 package. Si... |
H: Noise Gain of Op Amp
Why is the noise gain of an op amp always constant at $$1+\frac{R_1}{R_2}$$ and independent of configuration, unlike signal gain?
AI: There are two unwanted opamp properties - effective at the input nodes of the opamp: Noise and input offset voltage. When the opamp has negative resistive feedba... |
H: What is the path taken by the back emf current?
!
Where will the current flow through?
If ON current(back emf "current") will loop through A B and C
If OFF current will(back emf "current") loop through x y and z
AI: Where you may be confused is that there are actually two back-emfs - the voltage generated by the mo... |
H: Why isn't this LM2917 circuit working to turn off a transistor?
It was suggested to me that I should post a new question (original question here: Minimal Hall effect sensor circuit to keep something off after certain RPM achieved). The below schematic is for turning off the transistor Q2 once a certain RPM is achie... |
H: Can a current be induced in an HDMI cable that runs parallel to a 120v AC cable for 15 feet?
I just went to go unplug an HDMI cable and got shocked from the end of it! The only possible causes of this that I can think of are that the receiving or sending end of the long (50ft) HDMI cable is introducing a live curre... |
H: Reducing transistor switching time
I am currently required to study different ways of reducing the transistor switching time. From what i understand, the two most used methods are speed-up capacitors and Using a negative, non-linear voltage reaction to avoid saturation.
Unfortunately, i don't really understant how... |
H: What's the difference between virtual circuit switching and circuit switching?
Circuit switching's packets take the same route as virtual circuit switching's do.
So, how do I distinguish between virtual circuit switching and circuit switching?
AI: In the good old days of cables that consisted of a large number of c... |
H: Identifying a four-pin IC labelled EL 8+7 G8025
I want to know the purpose of a component named "EL 8+7 G8025" which was found inside a Nokia charger.
AI: Possibly an EL817 optocoupler, but I'll reserve final judgement until I see the photo. If it's a semiconductor the only common 4-pin parts used in this sort of a... |
H: Capacitor with n electrodes
In my book it says that the capacitance in a capacitor with n electrodes is (n-1)*Co, Co is a capacitance of a two parallel plates capacitor. I know how to distribute charge when there are 3 parallel plates( two of them are connected to single Q,and the third which is in the middle to -Q... |
H: I need 2 vcc pins on the arduino?
I need to connect the vcc pin to a bluetooth module but then I need to sue it again for a relay module what do I do?
AI: You just use the same pin twice. You can connect as many items to the 5V pin as you like as long as you don't draw more than around 750mA absolute max (the regu... |
H: Why it has used BPSK modulation after OFDM?
I am quite new to OFDM modulation. I am reading this from a tutorial. In one of its parts, for showing amplitude variation of the OFDM signals, there is a graph that has used 8 sub-carriers and BPSK modulation as below:
Now I have faced to this question, that we are usin... |
H: Why does oscilloscope still shows the signal even though its GND is not connected?
if i connect oscilloscop's + probe to the components's plus side it still shows the signal. But how can this happen without connecting the GND ?
AI: In most cases the o'scope ground is connected to the mains earth, and your circuit's... |
H: Using a MOSFET or BJT instead of solenoid
I'm trying to convert all relays and solenoids to transistors in a circuit to make it solid state. I have a small (150cc) 12V DC starter motor that is currently turned on by a small transistor turning on a solenoid, but now I want to use a larger transistor to be able to do... |
H: Analyzing input/output characteristics of a diode circuit
In "Fundamentals of Microelectronics" textbook. The question number 27 of chapter 3 is:
The part b of the question is:
And the solution of b from the solution manual of this textbook is:
Can anyone explain simply how did he got the solution ?
AI: Assume ... |
H: How will the diode act after its junction is penetrated?
Above is a circuit diagram with 2 sources V1 and V2, a switch SW, a diode D1 and a resistor R1. The points X,Y,A,B,C,D,E,F are terminals of the components indicated with red dots.
If the switch is OPEN as in the figure, the diode D1 is reverse biased and no ... |
H: Inverted PWM with ATTiny10
On a 10MHz ATTiny10, the following code generates the same 40kHz 50% duty PWM on both pins 0 and 1:
DDRB = (1 << PB0) | (1 << PB1); //Output on PB0 and PB1
TCCR0A = (1 << COM0A0) | (1 << COM0B0); //Toggle OC0A and OC0B on compare match
TCCR0B = (1 << CS00) | (1 << WGM02); //Clear on compa... |
H: Calculate Paging System
I have this problem to solve and I have the answers, but I'm trying to understand the concepts behind it.
A paging system has the following parameters: 2^32 bytes of physical memory; page size of 2^10 bytes; 2^16 pages of logical address space.
1. How many bits are in a logical address? 2... |
H: Controlling an RGB 5050 LED strip with Arduino and potentiometers
I recently found and old amplifier with the speaker taken out of it and thought it would look nice as a light feature. The switches and potentiometers are still in place but have removed the power supply.
After finding this project from MAKE Magazin... |
H: Which diode to use on my RC switch debounce circuit?
I am choosing parts to build an analog RC switch debounce circuit. I plan to implement the circuit described here: http://www.ganssle.com/debouncing-pt2.htm (see "An RC Debouncer").
(source: ganssle.com)
These are the other parts I plan to use for the circuit:
... |
H: What is the need for a pull-down resistor in this schematic?
here at the second page: http://www.skyeinstruments.info/index_htm_files/W200P%20Windvane.pdf
there is an external 470k resistor in parallel with the measuring device. it seems like the manufacturer wants users to connect this before measuring. but doesnt... |
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