Questions tagged [switching]
Switching can be defined as the change in state whether it be an analog, digital, or mechanical device. For digital devices, switching can be defined as a transition from HIGH to LOW or vice versa. For analog devices, switching can be defined as a change of operation within a transistor. Mechanical device examples include physical light switches or button switches. Ultimately, switching interrupts current from going into another conductor path.
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Why would an induction cooker periodically click when idle?
A typical induction cooker has output power adjustment which is usually implemented in two fashions. Higher power settings are "continuous" - the cooker outputs say 1200 watts all the time ...
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Power 12v DC actuator when 120v @15 amp saw is switched on
Problem: I want to use a 12v DC actuator to close a blast gate on my dust collecting system when I turn on a 120v 15 amp saw. The actuator can only run for a few seconds until the 6" stroke is ...
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How do I switch over between 2 AC power supplies with circuit breakers
I once saw a diagram where a house was supplied by a generator or from the grid by using 3 trip switches only.
It must be manual so I can select as preferred, and not a automatic system.
I also prefer ...
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50 views
Raspberry Pi relay on GPIO does not toggle, but does on +3V power
I am trying to toggle an SRD-03VDC-SL-C (3V rated) relay with a Raspberry Pi GPIO.
When I put a wire to the Raspberry Pi 2B ground pin and the other to a 3.3V power pin the relay works (it clicks). I ...
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Dimming LED powered with an AC driver from a MCU
I want to power an LED (Forward Voltage: 30-35V, Forward Current: 50W:1750mA) with an AC driver (link), the title says "Dimmable", so my first question is regarding drivers, all of them will ...
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What options do I have for a DC disconnect switch ~72VDC ~7A
I'm would like to implement a disconnect switch between my power supply and my system. Both the power supply and my system are fused, but I'd like the ability to safely disconnect the system for ...
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38 views
ULN2803 switch off
I have a ULN2803 that drives a higher current H-Bridge but the issue is the ULN2803 is inverting the output. I was thinking of switching the ULN2803 off until the micro-controller is ready to take ...
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Arbitrary switching of a large number of analog signals
I'm thinking about building a programmable patch bay for analog audio signals. There would be 24 analog inputs x 24 analog outputs with switching of any input to any output. Only one signal at a time ...
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What is the difference between circuit switching vs virtual circuit switching data communication?
The circuit switching method of data transmission which was used traditionally is way too similar to the virtual circuit switching (packet switching) communication technique. What is the difference ...
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Understanding ECU Lowside Output Circuit
Hello StackExchange,
I'm trying to understand this low side output circuit so that I can interface it with a load.
I will have to add another MOSFET/Relay/Driver of some description on the lowside ...
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1answer
24 views
I have a problem with using a voltage controlled switch in Pspice
When using the voltage controlled switch in Pspice, the current flowing on the other side of the switch is equal to the current flowing through the voltage source controlling the switch.
Why is it so?
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38 views
NE555 is heating
I have this 2 circuit and my 555 ic is heating up
1.) Switch circuit(momentary button toggle as on/off using 555 timer)
2.) Voltage regulator circuit(where sensors, lcd and esp8266 nodemcu is ...
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Switching characteristics in terms of TTL flip flops
I am a complete novice when it comes to electrical things. Fine at digital logic, haven't done electricity since high school.
I'm looking at flip flops and I've run into something called switching ...
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important aspects about MOSFET in making PWM inverter
In making a three-phase PWM inverter connected to the same single-phase DBR and AC source, switching devices with real MOSFETs are going to be used. What are important aspects that I need to consider ...
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How does PCIe switch handle Gen4 to Gen3?
I'm going to make a JBOD, the SATA HBA is 2X PCIe Gen3
and my new Mobo only support new PCIe Gen4 8x
I want to fully utilise a Gen4 8x to connect many 2x Gen3 HBAs, so I've found this Gen4 swich from ...
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How to use a N-Channel MOSFET for high side switching?
According to my research, mostly N-Channel is used for low side switching and P-Channel is used for high side switching. But if I want to use N-Channel for high side switching, what are the ways and ...
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How to connect a mains 24Vdc and an Emergency 24Vdc supply to lights that should switch the mains supply off when the emergency feed is switched on
I am looking for a solution for some lighting that was installed recently. The lights are single LED downlights that are connected from a direct connection to 24Vdc through a constant current driver ...
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Building a RS232 switch [closed]
I have an RS232 input and 2 audio lines that I want to switch to either computer A or computer B depending on the state of a physical toggle switch. Can anyone point me in the right direction of what ...
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Turn on/Turn off circuit using one momentary button. Also, turn off the circuit using a command from NodeMCU
I have this 5v and 3.3v voltage regulator circuit using 12v input voltage. This voltage regulator circuit is used to powerup my NodeMCU and several sensors.
Now, I'm having problems creating a circuit ...
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Turn OFF a PUSH ON/PUSH OFF circuit from NodeMCU
I have a PUSH ON/PUSH OFF circuit using one momentary button. I want to turn it off using a command from NodeMCU. In the image/gif below, I did manage to turn it off from the simulator. In reality it ...
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40 views
Where do I get this regulator? Alternatives?
I am searching for this 3-pin IC. It might be a low drop regulator switch. It is marked e3 N 1086 18 DR815.
It was faulty on a 42" LCD TV PCB. The TV could not turned on or switched from the ...
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Identifying a vintage lighting sequencer method
In India, on certain social festivals like Durga Puja, Kali puja etc, lighting decorations are done around roads etc, where various themes or stories are animated (such as stories from Aesop's fables),...
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ESD Protection for LED
I have a main board with microcontroller and two long distance panel boards with standard 5mm red LEDs with 3.3k resistors. I supply panel boards with 24V over 20m cable. Whole system power is ...
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Hot-swap controllers vs load-switch circuits and bidirectional current flow
We've got a battery of 50V connected to a load that may regenerate power, hence a bidirectional current could be present. We'd like to be able to switch on and off the load. We're looking at load-...
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Device to power either a red LED or a green LED
I have a green LED and a red LED. I want a sort of switch to turn either the red LED or the green LED on.
For example:
Where if the switch is off, the red LED is on but if the switch is on, the green ...
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46 views
Please explain MOSFET output characteristics and load line when used as a switch
My end goal is to switch a 9V-12V LED strip with an STM-microcontroller (3,3V level logic). So, I'm reading about MOSFETS (n-channel enhancement type in particular), but I'm very confused about the ...
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1answer
42 views
Two channel logical switch
I'm trying to make a theoretical automated battery charger using a reactor only with logical gates, and I wanted to use charge cycles between 30 and 80% for efficiency sake. I can output a 0 or a 1 ...
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73 views
Output capacitance of MOSFET
I have read in several application notes that there exists a region called the Miller plateau where the current into the Cgd is large such that almost no current enters Cgs holding the Gate voltage ...
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3answers
76 views
Voltage drop problem. Transistor, optoisolator, relay for programmable Christmas lights?
I'm trying to create programmable Christmas lights - a very simple circuit controlled via Arduino or NodeMCU. My problem isn't on the microcontroller side, but the basic electronics.
Now... I have 2 ...
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61 views
How I can command the four switches without microcontroller
I try to command 2 SWitch H bridge rectifier (two mosfet two diode) during the positive half cycle M1 switching and M2 be considered as a secondary switch that is continuously ON. During the negative ...
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MOSFET Gate Charge dependance on temperature at HOT, to determine charge needed to design driver?
i am designing this push and pull driver for external NMOS in my buck topology circuit.
i am well aware the gate charge ( based on Cgd) i need to turn FET ON and OFF at room temperature based on ...
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How to strobe high power led while maintaining constant current
I am trying to make a high power tv-be-gone. For those who don't know, it uses arduino or attiny to run through every IR power code for most tv brands. I have made regular ones that use several 5mm IR ...
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What should I do to switch off a P-Channel MOSFET as fast as possible?
I have a Power supply that powers circuit A (5V, up to 3A). When the power supply is disconnected I want to detect it and power ...
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1answer
57 views
High frequency relay options for 5V 20A DC
While researching for a while upon relays, I had a hard time finding out how to choose a relay that can switch high DC currents at frequencies up to 20MHZ. I found those solid state relays, but most ...
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Help understanding the TI TPS22917 load switch
I'm playing around with a TPS22917 load switch on its own (not in a larger circuit), and there are two things that don't make sense to me:
When the ON pin is set to low, I see ~0.9 - 1.0v on VOUT. ...
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Fast rise time reed relay
I am currently working on a project related that I asked before here. The purpose is to have 2ns rise time 30ns pulse width at 250V (with 50ohm load). Repetition is 30hz.
I tried avalanche transistor ...
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VGSS and Max VGS and VGD in the actual circuit - relation
I am using DMD2005 in one of our designs.
In one of the circuit,
This MOSFET is used as a simple inverter where Drain pulled up using 10K to VCC which can go up to 15V peak (rarely, typical always ...
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1answer
58 views
Transistor as a switch for normally closed operation from a Raspberry Pi GPIO
I was hoping to get some assistance with using a transistor as a switch in a circuit that I am working on. The project is to integrate a Raspberry Pi into an old Playstation 2 housing while utilizing ...
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TRIAC confusion
First for some quick background:
You might be aware of my other threads in which I pose a problem with micro-controller to WiFi-command an existing coffee machine which had (as happens with a lot of ...
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1answer
87 views
PNP high side switching with 100 mA load
I have this circuit to detect tamper status using a switch. When the switch is pressed (ON) then GND is provided to the base of Q3 (2N3906), so that transistor will be in the saturation region and can ...
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1answer
36 views
How to make one switch control multiple identical subcircuits?
I have an audio circuit with 8 identical subcircuits (one for each voice).
In each subcircuit or voice, a resistor controls one aspect of the sound.
I would like to have a switch which allows me to ...
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1answer
66 views
High-side pMOSFET does not switch to ground
This is the schematic in its basic form. It's an nMOSFET that gets driven by a pin of an Atmega328p, this nMOSFET on his turn, drives a big pMOSFET. The source is connected to a voltage regulator (9V6)...
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Miller Capacitance in MOSFET
The above image is regarding the Miller Capacitance present in the MOSFET.
I am finding it tough to understand the concept of Miller capacitance. I am trying and researching documents and videos to ...
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2answers
122 views
Optocoupler to switch 24V using Arduino
I am currently redesigning a circuit to switch a spring applied brake using an Arduino Micro.
The current circuit looks like this (please excuse if I'm using wrong symbols, I'm learning by myself):
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134 views
Stick-Slip Piezo Linear Stage Driver - Prevent the Load from Changing Driver Output?
I am currently trying to develop a circuit that generates ramp waveforms to control the motion of a piezo linear stage.
Specifically, two waveforms need to be possible to output: a slow ~250us upward ...
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Switching power line phases with inductive load
I have one question related to this schematic:
Scenario:
Source 1: AC source 220VAC, 50Hz, 120º
Source 2: AC source 220VAC, 50Hz, 0º
If I want to switch from source 1 to source 2 or from source 2 ...
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Step-down as LED driver leads to flickering
I received a LED driver board that uses an A6902D step-down as regulator.
Here the schematic of the driver section:
PWM_3 is the signal from the MCU: 500 Hz (tried ...
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65 views
Switching ethernet connection without a switch
I want to make a system to configurate ethernet connections to make different topolgies like ring or bus.Using 100baseT. Lets say i have 8 RJ45 female jacks and i would like to connect 1 female jack ...
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1answer
117 views
DC/DC Switching Converters: Is it possible to run a current-mode converter in voltage-mode only?
DC/DC Switching Converters: Is it possible to run a current-mode converter in voltage-mode only?
If so, is there an example using a buck converter?
In particular, I'd like to use UC3843 (LT1243) in ...
