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H: What's the maximum wattage air conditioner I can run for 8 hours through a 12V-120V inverter from 200Ah batteries?
I have an RV with two 100Ah batteries that provide 200Ah of 12V power in total. I would like to have a classic air conditioner (I've looked at swamp ones but they won't work for my needs) and I'd like ... |
H: How many ohm is the ADC port internal resistance of the atmega8?
I am trying to link a digital pin to a pad that's already wired to an ADC. I was wondering how many ohm the ADC port internal resistance is.
AI: Page 310 of the datasheet gives you your answer:
The analogue ports have an input resistance of \$100\spa... |
H: Recovering Dead Soldering Tip That's Not Tinned
Situation Breakdown
I've seen multiple posts regarding this certain topic, but, using all of those posts confirmed answer, the results never showed to be significant, long lasting, or even remotely yielding results in the first place.
I have a medium duty Wellers sol... |
H: Does the stability of a circuit depend on its feedback topology?
I am reading an article entitled "A Comparison of Two Approaches to Feedback Circuit Analysis" here.
If I understood the author correctly, we use return ratio instead of two-port loop gain analysis for stability analysis because return ratio doesn't d... |
H: Powering a microcontroller circuit using a differential voltage instead of an absolute voltage
So this is a more theoretical question. Imagine I have 2 perfect power supplies that I can set to whatever voltage I feel like (10 000 VDC for example).
Now I know that when it comes to voltage it's the potential differen... |
H: Can we control our computer's USB port?
what i want to do is : I want to connect a USB fan to my laptop and through programming want to turn on and turn off the fan. Is it possible to do so?
Please post your valuable suggestions.
AI: The easiest way to achieve your goal when you aren't experienced in electronics is... |
H: May I use CD4066 instead max 232, to convert rs232 UART(USART) level
As in the title, Is it possible to use the CD4066 as level driver through RS232 and TTL(USART)?
If it's possible how this work.
Thanks.
AI: The answer, once again, is "it depends".
Voltage levels
Figure 1. RS232 signal levels can be up to ±25 V. ... |
H: Amplifying AC voltage via DC supply voltage
at the moment I'm trying to amplify an AUX-Signal with a 12V DC supply
voltage. I tried die setup from Here's here as u can see in the sketch below.
simulate this circuit – Schematic created using CircuitLab
But all I get is just an annoying noise sounding horrible.
For... |
H: Altium: Using Find similar object to change all designator fonts at once
I am trying to use Find similar object in Altium designer to change all designator font in my schematic at once. First I Right-click on any designator on the schematic and select Find similar object and Ok. this makes all designators in the sh... |
H: Difference between 7805 and ref02 module
Both of these chips provide a constant supply 5V. My guess is, based on price and datasheets, the ref02 is much more precise and does better under varying temperature characteristics. Watching Peter Oakes video tutorials on modular power system, he uses three different opt... |
H: Software timers and interrupts on a microcontroller
I have few questions on software timers and interrupts on a microcontroller. Just for information, I use a dsPIC33E microcontroller.
The final goal is to implement a serial communication protocol: RS485 with Modbus. I managed to transmit and receive a message, and... |
H: Cadsoft Eagle Library: How to create device variant?
I'm creating a custom device in Eagle Library.
Generally I need two device, let's say they're CONN2.54_1 and CONN2.54_2.
These two devices are connectors, they both have 4 pins, thus they have the same symbol. The difference is the package, one is vertical mount ... |
H: Tristate buffer
I know that the "third state" of a tristate buffer is a high - impedance output. But my question is what about the input impedance? Will it also change to high - Z?
Whatever article I read about a tristate buffer, no one seems to talk about the input impedance, so my second question is that does it... |
H: Voltage Drop Across MOSFET in Ground path
I have an arrangement in which an NMOS is connected in the ground path to control the power flow as shown below :-
When the FET is on , current will flow & there has to be voltage drop across the mosfet. Because it is connected on 0V already, how to analyze the voltage dro... |
H: Alter boost feature on Guitar Amp from a fixed +6 dB to variable +0 to +16 dB gain
I have an Ibanez TSA15H amp head. Here is the schematic for the boost portion of the amp. The Boost SW just goes to an Off(Open)/On(Gnd) switch.
Currently the Boost is set at +6 dB. I would like to alter the circuit to allow for ... |
H: Control theory diagram for feedback circuit with compensation
An op-amp that drives a secondary gain stage might be given like this:
simulate this circuit – Schematic created using CircuitLab
Where it is important to note that FB1 is some impedence (unlikely to be purely real) rather than a resistor, and the same ... |
H: Can a capacitor be briefly charged above its voltage rating?
Lets assume I have a supercapacitor rated for 5v at 200F. That's 2500 joules of energy. My wall socket outputs 120V at a maximum of 15A, which is 1800 watts (or joules per second). If I hook up my capacitor to 120V DC at 15 amps for 1 second, I would expe... |
H: How to calculate voltage after rectifier?
Well, my question is:
"Is this calculator wrong?"
It calculates the voltage after rectifier as
Vdc = Vac * 1.41
It seems it forgets the voltage drop on diodes (0.7V + 0.7V).
Is the site accurate or we should we take into consideration the voltage drop on diodes?
Update... |
H: What is a C&I circuit?
What is a C&I circuit? I've seen it in a surge arrester catalogue indicating that those kind of surge arresters are to be used in C&I circuits.
AI: In this context it most likely means Commercial and Industrial. It is an umbrella term that covers lots of specific surge suppression types, but ... |
H: Isolation provided by transformers
I have a few questions about transformers and isolation. I will describe my understanding (maybe wrong) and questions about them.
Transformers provide safe isolation by disconnecting two circuits electrically. So now instead of touching one hot wire on the isolated circuit, you ... |
H: Op amp voltage reference with emitter follower
The purpose of this circuit (taken from the Minimoog) is to provide a stable -5V across the 100R load resistor, as accurate as the -10V supply and the ratio of the 5K resistors in the potential divider, and capable of sinking tens of mA. As I understand it, the transi... |
H: Solving the time constant in this specific circuit
I'm having some problems with this circuit from a tutorial website:
When the switch is open, the LED is on.
When the switch is closed, the LED turns off and the timer begins. After a while, the LED will soon turn on. It changes with depending values of the resisto... |
H: Capacitors and simple circuit understanding
I'm reading through Make: Learn Electronics and it has the following schematic for charging and discharging a capacitor. (Figure 2-80)
I understand that if I close switch A then I'll be creating a complete path for the electrons to flow, so the capacitor will charge.
Now... |
H: Can adding inductive load really reduce mains power consumption?
I have recently bought one of the cheap mains power meters (EL85-2042A to be precise) to monitor power consumption. It's really helpful when I need to know where my electricity bill comes from, or when I want to make sure I switched everything off bef... |
H: Why does LM317 burnout when output is shorted in this case?
LM317 voltage regulator has internal short circuit protection alongside with its thermal overload auto-shutdown, but in the circuit below it will simply burnout when the output is shorted. And its adjust pin gets internally shorted with its output pin.
I k... |
H: DIY BNC to F-connector or RCA?
I've searched for this until I'm starting to get sick. I decided to just ask for help. My friend has a CCTV camera with the typical BNC/Power cable, but he doesn't have a DVR. I have zero interest in buying any adapters or anything for that matter.
If possible, I would like to simp... |
H: Discharging a capacitor to a battery supply [simple circuit]
If I have the following circuit... (resistor & capacitors values are made up)
...and I hold down SW3 until the capacitor is charged, then I release SW3 then hold down SW1 why wouldn't the capacitor discharge into the negative terminal of the battery? (ac... |
H: Recharge AA batteries in device(skips taking batteries out)
In principle is it possible to recharge AA/AAA/9v batteries in the device they are currently plugged in?
There are numerous smart chargers for AA/AAA and 9V batteries. The process requires taking all batteries out charging then putting back in. When you ar... |
H: Programmable resistor
How do I make a programmable resistor for testing purpose? For example, I want the value of the resistor follow a ramp wave: 0ohm --> increase by 10k each 1ms, until reach 1Mohn and restart
AI: [ I'm going to ignore the case of connecting 3.3V across 0 Ω. I'm going to assume that there will a... |
H: Why are most parallel interfaces half-duplex and serial full-duplex?
I know what is difference between parallel and serial interface. I know also what does it mean half/full duplex. However, I don't know why most parallel interfaces are half-duplex, and most of serial interfaces are full-duplex.
Can anyone expla... |
H: What does the 1k resistor do in this schematic?
I'm very new to circuit design and have been doing lots of reading and research in order to understand everything going on in this schematic. I think I understand all of it except for the purpose of the 1k ohms resistor going from the control signal to the emitter.
Ca... |
H: Purpose of copper coils encountered in TV
I was recently working on an old TV similar to the one in this video here. I began to open it and encountered a part on the TV which I have never came across, I believe it functions similarly to a cavity magnetron.
Do anybody happen to know what part this is called (the e... |
H: SMP, NUMA, local memory - limits on numer of processors
I consider what are limits on number of processor in following models of shared memory:
a. each processor has only own local memory.
b. SMP
c. NUMA
I can't see any limits. Am I wrong ?
AI: When each processor has its own memory, you end up with separate com... |
H: Magnetron and microwave
I took apart a Kenmore microwave in order to salvage the magnetron, transformer, and the HV capacitor. The transformers, HV capacitor, and the magnetron from the microwave are intact. Is it possible to make the magnetron work without the microcomputer panel?
AI: Unfortunately, it is possible... |
H: Technical question on 16x2 LCD
In a 16x2 LCD there are 16 columns and 2 rows of characters, each character is made up of a grid of 40 pixels. My question is, do each of these characters have their own driver that drive every pixel simultaneously or is it a persistence of vision method, where one row of pixels at a ... |
H: What do I need to take in account when using a voltage divider as a voltage sensor?
I'm trying to make a voltage sensor (battery input[0-12v] ) with an output of 0-5v with a voltage divider. I'm gonna read the voltage through a microcontroller and I'd like to know if there is something else in the process I have t... |
H: Lowering the output of high amp current sensor for low amp use - good or bad?
By increasing the value of burden resistor or turning the wire several times around the CT an output can be increased. But is it a good practise to lower the high current non-invasive current sensor for low amp application in terms of har... |
H: what is the name of this yellow tape around high frequency transformer?
[
what is the name of that tape? , what it is the purpose of it?, can I buy it?
And if not, what is the alternative?
AI: It's an insulating, flame retardent polyester tape normally used within the layers of transformers to enhance the breakdown... |
H: Can the /OE pin of a buffer be left floating?
Here is a buffer from OnSemi which has an /OE pin that should be tied high for high impedance mode. For all active modes the pin value is stated as low. Would my buffer still work if I were to leave this pin unconnected or do I explicitly need to ground it?
AI: The /OE ... |
H: Can a brushless motor controller be used to control a 3 phase Induction Motor?
I've been seeing lots of BLDC motor controllers for dirt cheap. From my limited understanding, BLDC motors are almost the same as induction motors, except they use permanent magnets. I was thinking about taking the output and stepping up... |
H: Micro controller to set 'dial knob' mode on multimeter
Can a microcontoller be used to replace the "dial knob" function in a 'off the shelf' multimeter(10A max AC/DC). Is it easy to scale and micro control multiple identical multimeters using one microcontroller?
All multimeters operating mode is to be set using... |
H: TV screen in still photo: Why are there dark, blackish bands?
I was trying to capture the scanning process of a CRT TV screen in a photo. It gave me these dark, broad bands, shown below:
Fig. 1 a,b,c
I'm trying to understand the cause for this banding. However, I couldn't understand it clearly in very similar ques... |
H: Protect phototransistor from emitter-collector breakdown
I'm using the ADC on the reset pin on an ATTiny85 to detect an IR level. The reset pin is disabled in the fuses but I would like the ability to "recover" the fuses and reprogram the device.
The emitter-collector breakdown voltage of the phototransistor is min... |
H: Will this MOSFET switch circuit work?
I should point out that the LED I'm trying to switch is actually an LED strip with a one meter length and a total of 60 LEDs. Total power consumption is 4.8W at 12V. By the way, 'IC1' is the 7805, which converts the 12V DC into 5V DC.
This is the MOSFET I plan on using: http:/... |
H: FPGA filter - sinusoidal wave at clock frequency observed in filtered signal
I am using an FPGA to implement FIR filters, specifically for this question I have implemented a 12 point moving average filter. At the moment I am just using a signal generator as an input to the FPGA and putting in a pure sine wave at va... |
H: Multiple buck converters from same source?
I'm trying to build a 18 servomotor hexapod robot (6 legs), running from a 11.1 V Li-Po battery supply. I needed to step down the voltage to 5 V for the servos to operate, but the current requirements are very high (approx 10-14 A). I can't build my own high current buck c... |
H: Can I use the FFT to recognize musical notes on a piano?
I want to create a tool which recognizes a few musical notes (I know this is re-inventing the wheel). So I would play middle C, D, and E on a piano and it should be able to classify those notes. Here's how I think I should approach it:
Record a sample of me ... |
H: Interfacing TLC1543CN adc with 8051
I am confused with the I/O clock input mentioned in this datasheet: http://www.ti.com/lit/ds/symlink/tlc1543.pdf
Do I need to output clock from this adc to 8051 or do I need to use an external crystal for both the TLC1543CN and 8051 together?
AI: It's not that confusing to read. ... |
H: Oscillator circuit with TL071 opAmp for amateur very short range AM radio
I stumbled upon this nice video and thought I'd try to reproduce the experiment. Basically the video shows how to build an AM transmitter circuit using an opamp, some resistors and a capacitor. This is the circuit schematics for the oscillato... |
H: How to handle Register output in state machine with verilog
Assuming I wan't to implement a state machine in verilog, where I have 1 output which is a register
So the output must be in sync with the input clock.
I know that the transitions between the machine states should be implemented via sequential block, for e... |
H: Accelerometer sensor inside a car
Does an accelerometer sensor measure the distance accurately when it is used inside a car? and what is the misjudge percentage when it is compared with its odometer?
AI: An accelerometer requires integration over time to get velocity and integration again for position. But withou... |
H: Altium/Schematic Port I/O direction
It's been awhile since I've worked on editing schematics, and I can't seem to find the answer to a question I'm running into when editing my current schematic.
In Altium (or schematic software in general), there's the option to create a Port. The options are Input, Output, Bidire... |
H: Use One Solar Panel to Charge Two Small, Identical Batteries
I purchased the following solar security light kit a few weeks ago:
Harbor Freight #69643
Mounted system, worked great. FYI, the lamp uses a 6V, 900mAh, NiCd battery pack that is recharged with the included solar panel. I'm presuming that the controller... |
H: Arduino Pro Mini newbie question power supply
I am extremely fresh with this stuff (just started tinkering with my first project last week and fried one Arduino already)
Question 1:
I am basically supplying power to the Arduino from the back of my car's rear view mirror. The car's rear view mirror has 12v + ground... |
H: 2N7000 level shifter doesn't work under a certain voltage
I need to convert a 1.8V UART line to 3.4V.
I don't have the 1.8V voltage reference available, but I have the 3.4V reference, so I'm using a voltage divider to get about 1.8V.
This is my circuit:
However, it doesn't work for Vcc = 3.4V. In fact, it only wor... |
H: One particular part number not showing up on Eagle board layout
I finikshing up the silkscreen for a board about to be sent out for fab, and for some reason, I have two diodes whose part numbers are not showing up on the board layout, while all my other parts numbers are displayed just fine.
Here is one of the part... |
H: uncertainty of level measurement variation with frequency response
This is a typical extract from a spectrum analyzer data sheet.I want to know the reason behind the increasing uncertainty of level measurement with frequency response specification.
AI: The effect of stray reactances, usually shunt C and series L, g... |
H: Is it ok to cut the USB 3.0-specific lines on a USB cable?
I have a USB 3.0 micro cable in an assembly (below) where it attaches to a PCB on a sliding tray. Unfortunately, in the physical prototype, the cable is too stiff and causes the tray's stepper motor to struggle and stall.
Ultimately I will switch to an FPC... |
H: can i connect two similar antennas to two ends of a cable to to re-transmit the signal received from one end?
Scenario:
I've set up two wifi hot spots outside of my house at distance lesser than 20 meters as i don't get any ISP signal inside my house. But the problem is now i get very weak signal in my house becau... |
H: Drag any-angle trace Altium 10
I'm currently routing a schematic with Altium (10), it is very small and I use a lot of 'any-angle' traces. Altium can more or less route them 'fine', but the problems really begin when moving traces.
On this schematic I am often dragging and pushing traces, however, whenever I try to... |
H: Is it possible to *proportionally* reduce a DC voltage supply?
INPUT: I start with a variable DC supply (rated up to 5A) that varies between 0V and 24V.
OUTPUT: Let's say I'd like to get a directly proportional output voltage between 0V and 5V (i.e. a re-map of the original range, so that 0V becomes 0V, and 12V bec... |
H: Opamp Vos trimming in a single supply circuit
I have a need to trim the Vos of an op-amp (LT1006) running in a single-supply circuit (12.6V). From what I found so far the proper way to do this would be by using some bias voltage connected to both inputs rather than using ground as an input which would only work cor... |
H: UART effecting "character LCD(I2C)" in stm32f103
I'm using HAL API for programming, I programed if UART got some certain text then display the counter in character LCD, Then increment counter, If again got that sentence repeat these (Increment counter and displaying that).(I'm getting by interrupt)
When I send abou... |
H: Power supply for robotics project?
For my robotics project I am powering the arduino with a 12v 250mA source. I am using a DC motor l298 breakout board by iTead that allows a power supply of 5v to around 46v for DC motors. I am also using a geared DC motor that has operating voltage between 3v and 7.5v.
I drew thi... |
H: What's wrong with parallel conductors?
Regarding AC systems (like for homes and such), a circular path is called a parallel conductor. It's illegal (according to the NEC section 310) except under certain circumstances. But I have noticed that with DC circuits, circular conductors are also... taboo (for lack of a be... |
H: Transfer function of real components
In control theory, an accurate transfer function of the components of your system, and some sort of guarantee that they are independent (low output impedance and high input impedances) are important for understanding your system, if you want to model it accurately.
Sometimes, th... |
H: Most efficient way to power a 5 V circuit from a 14.8 V battery
I am making a DIY Raspberry Pi laptop. So far I have found a suitable board that will drive my display (M.NT68676.2A). From research I have found out that it will run off of anything from 12 V to 5 V, and that it uses around 3 A (I am not sure if that'... |
H: Connecting AVR running at 3.3V to a 2.8V I2C bus
I want to connect an AVR (ATmega48PA) to an I2C bus whose pullups are connected to 2.8V which is the operating voltage for other devices on the bus. The AVR is running at 3.3V.
Since SDA and SCL pins are open drain, the AVR, if connected, isn't going to "push" 3.3V o... |
H: What is the minimum spacing between inductors to prevent cross talk?
I have to put three inductors in a box. The inductors are air core with a diameter of 6in and a height of 4.5in. The value is going to be about 16uH. The inductors will see about 50Arms continuous at about 4kHz. Each inductor is on a leg of a 3 ph... |
H: Spark Plug/Ignition Coil: DC Pulse
If you have the following circuit with a step up voltage from L1 to L2, then when do you get a spark across the spark plug? I have three scenarios.
Scenario 1. You have the switch open, then you close it right away you get a spark.
Scenario 2. You have the switch open, then you cl... |
H: Wire sizing when connecting multiple motors
I'm connecting two electric motors and an electric heater in parallel together in a circuit, all three phase. Electric motor 1 has a rated current of 20A, motor 2 is rated 2.5A, and the heater is rated 25A. Branch circuit conductor sizing per the NEC is as follows: 125% o... |
H: Missing Connector Pieces
There are missing connector pieces in this PCB that I was working on and I swear that there was no connector there in the first place, so I ruled out me going insane.I circled the connectors in gray. Are these connector pieces for something else off the board I have?
PCB Details
This PCB ... |
H: Do the wattage from connected devices need to add up with the given wattage from a step-down converter?
A step-down buck converter converts 36V to 12V 36W.
Does it mean that the sum of all the wattage from all connected devices need to be 36W? OR Does it mean that I can connect multiple devices not producing more t... |
H: Two amps running through a transistor?
(Short disclaimer, I don't know much about electrical engineering other than what I have learned in physics in high school and the little I have learned from working with electrical engineers)
Is it common to have 2 amps running through a transistor (than can support it of cou... |
H: Powering 3.3V I2C from Arduino 5V?
I need my Arduino to communicate with a fairly sensitive 3.3V I2C device, and am using a Bidirectional Level Converter to step down the voltage.
However, I still need a 3.3V source (for the I2C device and Level Converter), and the Arduino shield I am using is blocking the 3.3V pi... |
H: Missing Component Pieces from a PCB
This PCB is from a old Sharp 1999 TV I have been reverse engineering lately; also sorry for any bad images. I have noticed that there are some "missing" components in the holes of: D4002, D4003, D4001, D4004, and C4002. Are there certain components that were once in those holes... |
H: Logic Analyzer shows voltage change in analog but not digital
While using a logic analyzer with analog voltage to test Digital Output Pin voltages on an Arduino UNO, I am seeing the expected digital output and analog output (HIGHs and LOWs for digital and 5V to approx. 0V for Analog).
I'm using a Saleae logic 4 to... |
H: Replacing IC with similar yet not sure
i have a coding machine here and on its pcb it has this IC ULN2003AN. it was burnt because of feedback polarity issue and i want to replace it with ULN2003APG. Is this possible, will it result to another problem. pls help.
AI: If the package is the same (14-pin DIP?) then ther... |
H: Drill Size Error in Eagle Cad
No matter what I do, I still have these errors. I don't know what to do to fix this. Please help!!
AI: If you zoom in on your layout, and then double click on any of those violations, it will take you directly to the section of the board where the violation is highlighted, in case you... |
H: How does UART know the difference between data bits and start/stop bits?
I understand that it is common for a UART scheme to use 8N1, meaning 1 start bit, 8 data bits, and 1 stop bit. Something like this:
0xxxxxxxx1
Where 0 is the start bit, the x's are the data, and 1 is the stop bit. In the case of multiple frame... |
H: Timing loop in finite state machine sync
I'm creating a FSM in VHDL to implement a serial transmission module. However, whenever I synthesize it, it throws a bunch of the same error about finding a timing loop.
[Synth 8-295] found timing loop.
However, the line it points to looks like this:
sync_proc : process (... |
H: Extra I2C on stm32f
I am using stm32f105 to control 5 I2C buses and some other peripheral circuits. The problem is that I used all dedicated I2C pins by other peripheral circuits. Is it possible I change a GPIO (General purpose I/O) pins as I2C.
For that purpose, a pin must be output for a while and than change to ... |
H: Accelerometer - Tilt Detection
I'm using the MMA8453Q for tilt detection of 45 degree in any axis. I'm a newbie to embedded devices. I have a few questions.
1) Should I be using Transient detection or Motion detection for my use case? I referred the Application note AN4071. But, I'm unable to understand the use cas... |
H: Why some TRIACs have mouting base connected to the main terminal?
Why some TRIACs have mounting base connected to the main terminal (one such example: BT139) and how to deal with it? Does it need to be grounded if the user can touch the heatsink?
AI: Why some TRIACs have mounting base connected to the main terminal... |
H: Using an audio amplifier with differential outputs with headphones
I'm planning to use TPA2012D2 (http://www.ti.com/lit/ds/symlink/tpa2012d2.pdf) audio amplifier from TI from my headphone audio project.
This amplifier has a differential outputs for left and right audio channels.
My question is, how do I connect thi... |
H: Top layer and Top solder layer Altium
I want to use a microUSB connector on a board I'm designing.
The dimensions of the connector that I'm using is in this Datasheet.
To make a lib I'm using Altium, after setting the dimensions here's how the part looks.
The problem is that I've checked that my dimensions do matc... |
H: UART with PC : Reciving absurd characters in PC
I am working on a project using Atmega16 micro-controller of AVR family. I am using UART for my project. I need to send data to my PC AT 9600 baud rate via an USB-TTL converter and view the data using 'putty'.
I am getting absurd data in putty. I am not an electronics... |
H: Can ADC take discrete signals as input?
Generally we give analog signal to ADC as input. As per my understanding, ADC has sample and hold circuit before voltage comparator. This sample and hold circuit samples the analog signal and hold for sometime. Here the signal may resemble like discrete signal. Now my questio... |
H: 12V Signal -> Relay -> Voltage Regulator -> Arduino mega analogue input. Will this work?
I have a system that sometimes generates a 12V signal to a DPDT relay coil, which switches on a 12V connection through the relay pins that can be used as a boolean signal to the arduino. I plan to do this by connecting a 5V L78... |
H: Kicking RJ11 cash drawer via PC's serial port
I have a Star CB2002LC-FN cash drawer. Normally, to kick it, it needs to be connected to the peripheral port of a receipt printer via RJ11/RJ12. The PC can then send a control signal to the receipt printer, which then in turn signals the cash drawer to kick. I believe t... |
H: SMPS dipping periodically when wall voltage is under heavy load
I'm going to apologize in advance as I don't have oscilloscope screenshots for the problems I'm about to describe, so words will have to suffice.
I've put together a non-isolated SMPS using the LNK304 as seen below (sorry for LTSpice). Perhaps a better... |
H: Motor works on 9V battery but not 9V power supply
I had a motor that was working on a 9 V battery
I now want to connect it to a charger that has 9 V output.
When I connect the motor to the 9 V charger sparkles poop out.
The charger is rated at 1.5A, is this too much for this motor?
I cant find the current rating o... |
H: I know it has small phase margin.. but why is it oscillating not at rails?
I came across an issue at my workplace with the following circuit. I did a OL response and saw that the gain margin is 21 db and the phase margin is 14 deg. Clearly not so good. Note that the 680nF cap is a populated capacitor on a board!!
... |
H: low-noise-amplifier datasheet lists negative dB for gain?
I'm looking at the RF3858 datasheet and on page 2 it shows the gain of the integrated LNA. There are two modes.
The high-gain mode has typically 21dB gain.
But the low-gain mode has typically -6dB gain.
Now what's up with the low-gain? Does that mean it's ac... |
H: Equivalent resistance between C and D?
I hate to add to the list of equivalent resistance problems, but having browsed through the existing questions here and elsewhere online I am still unable to redraw the following circuit to find the equivalent resistance between points C and D. All the resistors have equal res... |
H: Power N-Channel Mosfet as a Switch
I just want to use a BJT transistor to act as a interface between a microcontroller and a MOSFET. I need to turn on and off an N-Channel MOSFET for controlling a much higher current on high voltage. A power N-channel mosfet, as far as I know, requires at least 10V Gate to Source v... |
H: Simple circuit with transistor using Raspberry Pi
I'm trying to use a Raspberry Pi to control a set of 4 LEDs. I'd like to control the LEDs in software by using a GPIO pin. Here is the schematic I've come up with... (please ignore the wire in the top right corner of the diagram, the transistor should make or break ... |
H: Is it possible to redirect print streams to debugger in Atmel system?
Is it possible to configure stderr and/or stdout to make it such that when a printf() is called the string is displayed in the debug console in Atmel Studio?
I do know that it is possible to set everything up so that printf() uses the UART or an... |
H: Sending a divided clock through a non-dedicated clock pin?
I'm moderately new to FPGA's, and right now I'm working on code to interface with a DAC. I'm using this PMOD DAC , and a Nexys 4 DDR fpga. Right now, I'm connecting them through the JB PMOD header.
The DAC requires a clock pulse (I'm sending in a 50MHz one,... |
H: What kind of component lets me measure distance in a small space?
I have bought a beautiful old radio, which I'm trying to convert into a DAB radio (there's no future for FM radio in my country).
Of course I could just use a DAB receiver, plug it into the old radio's speakers, and be done, but there's no fun in tha... |
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