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Is it dangerous to have no cover on a fluorescent tube (bathroom light)? [closed]

Is it dangerous to have no cover on a fluorescent tube (bathroom light)? I have a bathroom light above my sink with two fluorescent tubes. The acrylic cover sheet that slots into the fixture is "...
Jocelyn Yeoman's user avatar
0 votes
2 answers
50 views

capacitive filtering of power line transients without power loss

I've been researching so-called "surge capacitors", which are claimed to augment surge protection devices (SPDs). The claim is that SPDs usually have at least a 5-10 ns response time, and ...
Special Sauce's user avatar
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0 answers
27 views

How can I switch between battery tracking mode and input voltage regulation mode on the BQ24210?

I'm trying to create a circuit in which a BQ24210 automatically switches between charging a battery via battery tracking mode and charging it via input voltage regulation mode. This is done by having ...
gins123's user avatar
0 votes
1 answer
50 views

Can I mix 5v power sources? how about 24v power sources?

Hello and thank you in advance for pointing me in the right direction. I finally started designing my own PCBs. If I set up a PCB with a 110 to 5v power source (HLK-PM01), could I then add another 5v ...
Cancun Manny's user avatar
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0 answers
30 views

Controlling a device in a car using a button and ignition

I need to connect a device to my car. I thought about using an XOR gate because: A - button B - car ignition. If the car's ignition is off (0), pressing the button (1) will turn on the device (1). If ...
jminhal's user avatar
  • 21
0 votes
1 answer
35 views

Why don't LED datasheets specify a maximum rated voltage?

I understand that (i) LED's have forward voltage drops (Vf) and (ii) that exceeding the dissipation wattage or max current can damage the device; thus one uses a series resistor to limit the current. ...
KJ7LNW's user avatar
  • 2,022
0 votes
0 answers
58 views

Embedded software extraction [closed]

1: I have a soldering iron and hot air controller board. It comes from an SMD soldering rework station by the same name. Mine is unbranded, but I have seen about half a dozen sellers selling the same ...
HAL 9000's user avatar
0 votes
0 answers
28 views

Using a Latching Button for Car Hazard Lights with LED Indicator

I'm attempting to learn more about electronics with this small project I am using a latching button . I connected the button to the ignition wire of the car because I want the LED to stay on. My ...
jminhal's user avatar
  • 21
0 votes
2 answers
54 views

Why does 9.7Vrms == 27 Vpp? I thought it was 9.7/0.707 == 13.72!

At first, I thought this calculator was wrong, because I have always used an RMS to peak-to-peak conversion as \$ V_{RMS} = \frac{V_{pp}\sqrt{2}}{2}\$: https://benchmarkmedia.com/blogs/calculators/...
KJ7LNW's user avatar
  • 2,022
1 vote
1 answer
55 views

Maximizing magnitude of fields created by an antenna

I have a small loop antenna (\$C\$ = circumference<< \$\lambda\$ ). I am interested in the fields created by this loop at a distance \$D\$ along the z axis also small compared to \$\lambda\$. I ...
DarkBulle's user avatar
  • 395
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0 answers
25 views

Choosing a power supply for making a Hasel Actuator [closed]

I'm planning to build a HASEL actuator and need to buy a power supply. There are many options out there, and some are quite expensive. I've found a few affordable ones and was hoping you could help me ...
forasle's user avatar
0 votes
1 answer
58 views
+50

STM32G4x 2 chanel Contunious Conversion Mode ADC DMA voltage read problem

I am using STM32G431KB Nucleo for measure a potentiometer voltage via ADC1_IN1 and ADC1_IN2 channels with Scan Mode DMA. And my samples arrays are always zero, no change. I share my code below. What ...
MSB's user avatar
  • 27
0 votes
1 answer
36 views

STM8S003 TIM1 prescaler seemingly not affecting anything

I'm trying to use an STM8S003 chip for a pretty basic function, so I'm standing up the TIM1 peripheral to use output compare. Everything seems to be functioning correctly, except that the pre-scaler ...
InBedded16's user avatar
0 votes
2 answers
52 views

Do dimmers affect consumption?

I'm almost hesitant to ask this question because it just seems like I'm going to get lambasted with the obvious but I truly do not know the answer. This is a two prong (no pun intended) question. If I ...
Paul Sebesta's user avatar
1 vote
2 answers
145 views

Why do birds not fluff up when they land on super grid transmission lines?

I’ve been testing a home brew Van de Graaff generator on my younger sister. When I do that, her long hair fluffs up like that scene in the Pink Panther cartoons when he’s tumble dried. Puff! Birds, ...
Paul Uszak's user avatar
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0 votes
0 answers
50 views

Acceptable resistance between hot (mains) and ground (earth)?

A DIY project I'm working on uses electronics embedded in concrete, including 110V AC heating elements. As I was verifying my wiring before testing the device I was surprised to discover conductivity ...
sirbrialliance's user avatar
0 votes
3 answers
43 views

Esp32 controls a 12v coil relay through PC817 and 2N7000

I need to control a 12v relay with an Arduino nano ESP32. Can somebody check if the circuit I designed is good? Components list: MOSFET: 2N7000 (N-channel); Optocoupler: PC817; Diode: 1N4007; Relay: ...
PaoloRos's user avatar
0 votes
2 answers
47 views

Are variable capacitors compatible with breadboards still available?

Variable capacitors are used less, since the preference is for digital adjustment. And through hole parts are used for less, since the preference is for SMD. Finally, many variable capacitors have ...
SRobertJames's user avatar
  • 1,121
2 votes
1 answer
98 views

Howland-based multi-range current source, has this configuration been published anywhere?

While playing around with the Howland current source in a simulator, I produced a simple multi-range configuration I've not seen published before, and haven't been able to find with an (albeit brief) ...
Neil_UK's user avatar
  • 169k
0 votes
0 answers
43 views

I2C: SDA and SCL Lines Pausing Between GND and VDD

I'm seeing communications on an I2C bus are momentarily pausing between GND and VDD (3.3V) during some transactions. See scope shot of the SDA line below: Since it stops at about 800mV, this is below ...
oneil's user avatar
  • 53
0 votes
5 answers
104 views

Why, when conductors are connected in series, their current strength is equal?

Why, when conductors are connected in series, their current strength is equal, because the resistivity of the conductors can be different?
Vladislav Butko's user avatar
1 vote
2 answers
136 views

Will this FM transmitter work?

I found this schematic on circuit digest. I have tried to simulate it in LTspice. That's the wave I got from the simulation. Most of time it's just DC and does not oscillate at all. Is this going to ...
kile's user avatar
  • 907
1 vote
0 answers
63 views

Wien bridge oscillates at 6x expected freq and amplitude oscillates too

A while ago I made a Wien bridge oscillator to go from ~500 Hz to ~1 MHz, using an NE5532 opamp and stabilizing amplitude with the typical opposing diodes method. Worked fine, but the output was too ...
Hal Gee's user avatar
  • 13
0 votes
1 answer
50 views

Part Identification and Circuit clarification

i am trying to repair a laser driver circuit. Apparently, it was connected to a lab power supply (the driver is rated 4-5,5V, 8A) and someone turned the knob, so it got way higher voltage. I ...
Boldar's user avatar
  • 68
0 votes
1 answer
17 views

KiCAD PWR_FLAG issue on DW01A circuit

I am building a TP4056 based battery charger circuit on KiCad. The ERC check throws the error as per the screenshot. Do I need to add the PWR_FLAG on VBAT- and VBAT+ nets as well or is there any other ...
Rakesh Mehta's user avatar
0 votes
1 answer
91 views

What circuit could I use to detect that there is no ground connection?

I'm trying to design an Electric Vehicle Supply Equipment (EVSE) and want to add a circuit capable of detecting no ground connection. I've seen that some EVSEs can detect this, so my question is: What ...
WalterPH's user avatar
  • 440
2 votes
2 answers
248 views

What does impedance seen from input/output mean?

I am seeing it usually like impedance seen from input/output when we need to match impedances between two circuits. What does it even mean? Does impedance change based on where do you look from?
Nabla's user avatar
  • 271
0 votes
0 answers
36 views

How to short time delay controller?

I have an old keyboard which I use for decorative purpose. It has RGB lights which turns on for few seconds when a key is pressed. I want to keep them on at all times. How to achieve this? Can I ...
Saransh Bairagi's user avatar
4 votes
3 answers
478 views

Issues with ICL7660 ICs from eBay - Overheating and Failure

I recently purchased several cheap ICL7660 ICs from eBay to use in an OpAmp circuit. Unfortunately, I've encountered issues with these components, specifically overheating and subsequent failure. Here ...
Special.Guest's user avatar
0 votes
1 answer
41 views

The LED does not blink with PIC16F84A-201/P

Environment MPLAB X IDE v6.20 PIC16F84A-201/P PICKIT3 The adaptor board for PICKIT3 looks like this: https://www.amazon.com/Comimark-Programming-Adapter-Universal-Programmer/dp/B07V5SHN5V/ref=sr_1_9?...
dixhom's user avatar
  • 247
3 votes
2 answers
70 views

Numbers in Generating Phase Coherent Electronic Systems

I am reading the following paper 'Störmer’s numbers in generating phase coherent electronic systems' written in 1969. More or less I understand that in microwave applications there is clearly a use ...
Mikhail Gaichenkov's user avatar
-1 votes
0 answers
31 views

Current concept doubt (charging/discharging) [closed]

Current concept confuses me alot in electronics, have some questions regarding the same- Suppose my battery rating is 5V 1A (1000mAh) and suppose there is an Rpi to which i want to power and its ...
L Lawlit's user avatar
0 votes
0 answers
29 views

Voltage regulation for backup battery power circuit

I am building a GPS tracker where I need to have the option to drive the device from an external power source up to 40 V and have an internal 3.7 V backup battery. My GSM Modem (Quectel M66) needs 4 V ...
Rakesh Mehta's user avatar
0 votes
0 answers
43 views

Discrepancy in Diode Simulation Results between LTspice and Standard Test Conditions [closed]

I'm currently working on simulating diodes in LTspice and have noticed a discrepancy between the simulation results and standard test conditions (1000 W/m2, 25 degrees Celsius. The results have been ...
Mohamed Haj hamido's user avatar
0 votes
0 answers
33 views

How to produce an intermittent square wave (produced by XY-LPWM module)?

I'm a novice DIY guy trying to make a PEMF device (Pulsed electromagnetic field therapy). According to a paper I'm reading, I need to produce two PWM waves like this (B0 and B1 in the abstract picture ...
Lam Le's user avatar
  • 109
2 votes
3 answers
112 views

Deciphering workings of a printed circuit board for a night-light

I am new to electronics and am trying to understand how a particular circuit on a printed circuit board (photographs below) actually functions. The board represents the entire device which is a LED ...
CrimsonDark's user avatar
1 vote
0 answers
28 views

FLC100 Flux Gate: How does the reference voltage work?

I am using a set of six Stefan Mayer FLC100 flux gate magnetometers to measure a magnetic field along 3 axes. My current understanding of how to use these is that you take the differential ...
matt 's user avatar
  • 11
2 votes
1 answer
60 views

Transistor AND gate problem

I am new to electronics and I built a simple AND gate from 2N2222 transistors. I want to use the output from the AND gate in a different circuits not just an LED but maby an OR gate. Can someone tell ...
RedEndermanSK's user avatar
-1 votes
1 answer
100 views

Help on IC identifying

Please help me on identifying the following chip. Smd mark says "5MM 615". Picture: Addetto better picture. It appeaers to me 5MM on the first line with 5M overlined. 615 on the bottom line ...
salvatore cirasa's user avatar
1 vote
1 answer
68 views

How does this 230/400 V induction hob draw current? [closed]

The instructions that came with a new Electrolux EIS62441 induction hob didn't specify any recommended breaker sizes or supply cable cross section requirements. The hob comes with more than 1 m of ...
asdfghjkl's user avatar
0 votes
0 answers
46 views

Why does the SPI bus with 2 devices crash in this setup?

I am using Feather M4 express development board with DC Motor + Stepper FeatherWing and Ethernet FeatherWing stacked on it. The idea is to control the steps of the stepper motor by reading the encoder ...
dreamcoder's user avatar
0 votes
6 answers
79 views

Do components "draw" current, or is it forced through them?

If you attach a typical LED to a 9V battery, the LED will burn out because there's too much current. If you add a resistor, it's fine. You can charge your phone with a 1.0A charger, a 2.4A charger, ...
Neil Barnwell's user avatar
0 votes
0 answers
50 views

DC-DC converter to make variable output +/-70V from 5V input

This is a SEPIC DC-DC architecture from Texas Instruments to make a variable output from +/-5V to +/-70V. Iwould like to understand the principle of how the negative voltage is being made from the ...
Andromeda's user avatar
  • 475
0 votes
1 answer
25 views

What is this IC marked '63M44P .420'?

I have an IC in an SMD package with 6 pins. It is used in switching power supply. It is marked as: First row: 63M44P Second row: ...
Иван Боев's user avatar
0 votes
1 answer
91 views

Does the FFT in LTspice not work properly?

I wanted to do an FFT of a square signal in LTspice. Here is the simulation: Here is the result of the FFT through R4: There is no reason to have frequencies below 100 kHz according to theory. What ...
Jess's user avatar
  • 2,478
1 vote
0 answers
48 views

Working of differential pair using MOSFETs

I am currently learning about differential pair using MOSFET from this course. In this particular lecture, the teacher says that to have a differential pair we need to apply the second signal v2 at ...
tinkerer's user avatar
  • 180
1 vote
1 answer
87 views

Unable to use a MOSFET to connect two capacitors in series

I am trying to design a circuit such that I can connect two capacitors in series by applying a gate voltage to a N-type (specifically IRF530N) MOSFET. I am getting results I do not understand. When I ...
Skeeter4life's user avatar
0 votes
0 answers
41 views

Help identify what IC is it?

help please identify what IC is it (or even manufacturer) ? (22C3TWB0c e3 and and few triangles logo)
Lion's user avatar
  • 11
0 votes
0 answers
21 views

AC-to-DC rectifier and DC-to-DC converter

I am currently doing an assignment featuring an AC-DC EV Charger topology as shown below. I have obtained answers for (a) and (b). However, I am unable to derive the equation exactly as given in the ...
miu.spiro's user avatar
0 votes
0 answers
15 views

Difference between Echelon TPT/XF and RS485 transceivers

We are going to connect to a LonWorks network and all devices connected to network have TP/XF-78 transceiver. Can anyone describe the difference between the two?
BHP's user avatar
  • 173

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