# All Questions

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46 views

### crystal stability gone wild on higher speed microcontroller

I made a board with AT89LP52 (higher-speed brother of AT89S52) and at the crystal connection I used a 22Mhz crystal with 5pF NPO ceramic caps grounded. The circuit itself works along with the ...
50 views

### How can I power a 3.3v circuit with a 9V power supply and two AA batteries?

I have a circuit that runs on 3.3v. I want it to be able to operate on two AA batteries down to about 2.2v (or until batteries are dead), and also with a 9V power supply. When the power supply is ...
21 views

### Building DIY TrackIR, need wiring help

I'm attempting to build a homemade head tacking unit for use in computer games using infrared LEDs for my kid. I followed one tutorial where they were wired in parallel. After doing more research, I ...
26 views

### Does magnetic flux depend on the orientation of the ferromagnetic rotor?

I have attached a picture of a reluctance motor setup. When I turn on the AC source, magnetic flux lines will build up. My question is, will the magnetic flux will be a function of the angle turned ...
35 views

### Pocklington's equation - how to get $\omega\times\epsilon$ without knowing frequency?

I'm trying to think of how to get $\omega\times\epsilon$ here. It must be simple, just missing something. I know the length of the wire in terms of lambda, the radius, and the voltage on the wire. ...
80 views

### STM32: SPI hardware to implement custom serial interface

I want to implement SDLC communication on an STM32 (assume I can pick any one up to M7) using the existing HW in it. SDLC is a full duplex synchronous serial interface. In my case, it uses ...
46 views

### Help to identify an uncommon thermistor

I am trying to identify a thermistor that was used in a "smart thermostat". It is a surface mounted small part (0603 form factor), bears no markings. I measured the resistance across at a few ...
35 views

### Painted PSU and Case - How do I connect my Anti Static Strap? [migrated]

I'm purchasing an anti static strap due to my house being all carpet. My case (https://www.amazon.com/dp/B07H4V9T9R/) and my PSU (https://pcpartpicker.com/product/8P7CmG/evga-bq-500w-80-bronze-...
28 views

### What terms to differentiate between a quasi-synchronous motor (eg an induction motor ) and a completely asynchronous motor (eg a universal motor)?

I am editing a table of motors. I am looking for the correct terms to distinguish two types of motors: motors whose speed is less than the AC frequency (all inductions / squirrel cage motors) from ...
37 views

### How to turn on 9V water pump when fire detect using arduino uno

I want to write a program that detects fire using fire sensor and on the water pump.Simply on the waterpump when fire detects and goes off when fire is not detected. the fire sensor works fine when i ...
97 views

### What is the proper term for a board that replaces a chip?

I've been working on some vintage electronics lately. In the course of this work, I've found that in some cases it is much easier to design a circuit to replace an old DIP chip that has failed than ...
32 views

### Standing waves modes inside a cavity resonator

Follow up postI have researched the concept of a rectangular cavity resonator and have come across the term modes. For a given frequency one can have multiple modes. What do these multiple modes ...
69 views

### PIC12F508 “Calibration value is invalid”

We use PIC12F508 chips by the tens of thousands. We normally purchase from people like Future Electronics or Arrow. However, I see that our purchasing people are now buying 12F508 chips from someone ...
81 views

### Power supply circuit capacitor selection

I'm planing to use this circuit for my op amp test but I don't understand capacitor selection Why C1 and C2 selected 2200 uF but C3 and C4 selected 1000 uF? (C3 is 1000 uF picture is wrong) I tried ...
37 views

### Is this circuit for Piezo Transducer sufficient? [duplicate]

I want to drive this Piezo Transducer (https://www.mouser.com/datasheet/2/670/cpt-9019s-smt-1310960.pdf) directly from a pin on my STM32F0 microcontroller. I don't want to use a BJT transistor because ...
38 views

### PWM frequency and sine waveform generation

I am trying to follow some guides (for instance this) to generate some analog signals (for instance a sine wave of 50 Hz) with Arduino (but my questions are general). But I have two basic questions: ...
105 views

### Is there any memory cell that can store more than one bit?

SRAM, DRAM, Flash, EPROM - all of the memory cells contain one bit of data each. Is there any memory cell that can store more than one bit, e.g. 2 bits/4bits?
32 views

### Calculating steady state output using Laplace transform

I've tried to obtain the the steady state output with the help of final value theorem and multiplication properties of Laplace transform.But I'm not sure whether I've solved the problem correctly or ...
80 views

### How does such an USB step-up 5V-12V work?

I just bought a cheap USB 5V to 12V step up converter: Surprisingly, it works very well. There is few place for electronic components (maybe in the USB connector?), how can we do a 5V to 12V ...
80 views

### Which has longer response time: a digital signal processing on arduino or arduino with a filter circuit?

I am interested in knowing which method has a faster output: Method A: Arduino takes in 3V signal with a noise of 120Hz noise. The noise has an amplitude of 800mV. The Arduino does a digital signal ...
40 views

### VHDL : Not understanding Hierarchical or External Naming or how to use them

Note: I using quartus ii v13 with vhdl 2008 I am trying to access the current state of my state machine from inside my test bench file. From my understanding I should be able to do this with External ...
39 views

### Finding Charge of a battery without knowledge of prior charge

We have a battery connected to some circuitry. Currently, we have all charging of the battery going through a LTC 2944 sensor, and all discharging going through another one of those sensors. We are ...
47 views

### Creating a 5 volt (ish) power pack from 18650 batteries

I want to create 5V power supply for a portable lighting project, using 18650 batteries. The power supply needs to provide power to an arduino (which can take 3.3V to 13V input) and some addressable ...
140 views

### Visual understanding of EM fields within a rectangular metal container

I have the following scenario setup inside a rectangular metal container. The container size is 12.03m by 2.39m by 1.84m (lxbxh). Additionally, inside the container I have placed 4 antennas equally ...
63 views

### How can one make a low cost but high powered UV light source [on hold]

I need a strong UV light source with a peak at 365nm. I know they have lamps systems for this purpose, but they are thousands of dollars. I am going to use this for cross-linking hydro-gels that are ...
32 views

### PISO buffer for the MachXO2

I'm trying to design a "double-buffer" structure similar to that used in UARTs (for receiving). In my case, it is for samples from an ADC. I shift them in, and at some point my logic detects a ...
40 views

### Switching Sine wave at specific duty cycle and Frequency [on hold]

How to get the waveform as shown in the image .The sine wave is already generated throgh xtal oscillator circuit.
60 views

### Half-wave voltage doubler question

I've been having trouble trying to understand the circuit mentioned in the title, which you can see in the picture below. Note that I'll be using the ideal diode model in my explanations. In case ...
40 views

### Additional V+ pin on ALD1106

I'm working with ALD1106 as part of a circuit I'm testing, but looking at the datasheet for the part, I'm confused by the addition of the V+ pin. It doesn't look like it's tied to anything in the pin ...
43 views

### How to drive a 220V AC voltage regulator programmatically? [on hold]

All voltage regulator I saw on the net are controlled manually, mainly through a potentiometer. I currently use one of them to control the speed of a fan. Now I want to control the speed automatically ...
42 views

### Can I test the nominal value of the MOSFET with one circuit? [on hold]

When this circuit is used, the MOSFET is burned, so it is questioned that the MOSFET supplied by the supplier does not reach the nominal value. For example: use IRLR024 (55V/17A), burn at load (24V/2....
90 views

### Voltage Controlled Current Source - help needed

I am designing a voltage controlled current generator for the currents in a range from 0 - 2.5mA. The load resistance is within the range of 0 - 5k Ohms. I decided to go with difference amplifier ...
676 views

### How to control the output voltage of a solid state relay

Considering this solid state relay: The output voltage can be from 24 to 380V. How can I control this voltage? Is it proportional to the input voltage? What I need is a voltage regulator that can be ...
36 views

### Can I design a board that can charge a phone while it is powering a slave device via OTG? [on hold]

I have a USB-C phone that is connected to a board which is then connected to a slave device. The phone is in host mode while it is connected to the other device and I can issue commands and receive ...
37 views

### How to determine the length of the last data field in a SDO block transfer?

I've got a problem with the implementation of the CANopen SDO Block Transfer. The transmission is ok except the last block: ...
104 views

### Is shielding the entire circuit with a faraday cage a good idea?

Let's suppose I have a circuit which contains a 3.3V MCU and a buck converter (let's think that its frequency is higher than 400 kHz). I'm wondering if shielding the entire circuit would not a good ...
44 views

### Add usb port in old hi fi music system [on hold]

i want to add usb in my old sony music system to power up the audio bleutooth receiver from inside . This is the link of the repair manual https://elektrotanya.com/sony_hcd-rv555_ver.1.2.pdf/download....
36 views

### Protected 3.7v battery as replacement for 3.8

I have a set of bodycams that need replacement batteries, and i cannot find anything suitable short of 400 quid to send them back to manufacturer. At that price i might as well spend the extra 100 and ...
139 views

### What causes a thorn like feeling when your put your hand in water in electronic appliances?

I live in India, the voltage supply in houses is 220V. Sometimes, for example in my washing machine, when it is full of water and I put my hand in it, I get a feeling like a thorn/tiny nail is ...
26 views

### Mid-Infrared sensor cover (not PIR)?

I came across this great little sensor (AK9750), which can detect people in 4 directions with a good range of about 2 meters. However, its spectrum sensitivity is between 5000 and 7000 nm, which is ...
59 views

### Why must a block in NAND SSDs be erased before it can be reprogammed? [on hold]

Before programming a NAND based SSD in page-level we have to always erase by block-level which increases write amplification. why is it so and how do we mitigate it? what is the necessity of erasing ...
67 views

### Struggling to get an amplified sine wave over a small inductor at low frequencies

I am building a power amplifier circuit to amplify a sine wave over an inductor from a function generator. However because the inductor is small and i'm running at a low frequency I am getting ...
61 views

### CC/CV Buck controller

in this model can anyone explain me how is it going to work in CV mode and where is the potential divider and all, like where is the Vfb
25 views

### Altium Description Item ID change

I am using a library that is located on our company's servers. This library is linked to Altium. After finishing my schematics, I noticed that a description for a type of resistor I was using was ...
30 views

### How to determine laser diode beam range [on hold]

I am using this laser diode PLT5 520B. I want to know the range of distance the diode can output the beam. It is not mentioned on the datsheet.
69 views

### Does current in neutral wire flow like this? [duplicate]

I've read neutral wire in 1 phase AC at home has almost 0V at both ends. But still current flows through it. So I've assumed 0.1V potential at the other end near a resistance (bulb). Now there's a ...
53 views

### How to find out the history of how many microns for lithography used on silicon wafer?

I think as of 2019 it is said that 7 micron is the smallest possible? I wonder how much it was in 2010, 2000, and 1995. Where can such chart be found for what the number was possible in the past?
55 views

### Is isolation required for MOSfet gate driver's and microprocessor's power supply?

I have designed a 62W , 24V-5V buck converter operating at 250KHz. I am using TI's UCC27200A gate driver and Infineon's Optimos 4. The problem is that the driver doesn't have any kind of isolation ...