Questions tagged [switches]
Devices to interrupt or route a signal or power one of several ways.
2,689
questions
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10 views
Convert values of utilization category from AC7a / AC7b to AC5a / AC5b - Is it possible to estimate?
I have a switch which is rated at 440V and 25 A for utilization category AC7a and 8.5 A for AC7b. Is it possible to give an estimate about the maximum current for appliances of categories AC7a / AC7b?
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19 views
Bypass touch switch on humidifier circuit board
i have a simple humidifier that only powers on by a touch sensitive switch.
I need to bypass it because when the power is off after that the device doesnt start automatically.
I tried some things but ...
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1answer
71 views
How can I reduce the number of microprocessor pins I need to use?
In my circuit, 5 choices are made by the user through jumper.
Please look at the picture:
I have to use 5 pins of microcontroller in this method.
How can I reduce this number of pins?
Is there a ...
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1answer
23 views
Can this Eaton T0-2-8211/E changeover switch between multiple sources
I have this Eaton 1|0|2 style changeover switch T0-2-8211/E. Can I use this to switch between 2 different input sources?
My intention is to use it to switch between shore and generator power on boat. ...
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0answers
34 views
Digital Off Delay Timer
New to electronics. Found an off delay timer with limit switch input that has this specs: "Power input : 230 Vac ±15%,50-60Hz Standard. Relay output : UV-C SPDT relay 8(1)A, 250V AC" Just ...
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3answers
76 views
Ways to reduce Vgs range of Logic Level MOSFET
I try to control two MOSFETs from one microcontroller pin, where one MOSFET shall turn on 400 ms after the first one. The second MOSFET is switching on a relay coil.
My idea was just to use a RC ...
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0answers
24 views
Using a bypass capacitor with a no-neutral smart light switch on two lamps in series?
I am considering purchasing a smart light switch which does not require a neutral wire and instead works with a bypass capacitor parallel to the load lamp. This switch would control two lamps in ...
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2answers
39 views
Add second sensing circuit to already wired reed switch
In my house I have a mechanical water meter with a 2 wire reed switch that sends a pulse every 10 liters to (I suppose) an electronic meter to witch I don't have access. I'd like to connect a circuit ...
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2answers
65 views
Universal series motor control using relays
I have a 220AC universal series wound motor I am trying to connect to a RF Remote Switch using relays and full bridge rectifiers.
I have come up with the following schematic:
The RF Remote Switch ...
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0answers
26 views
Is it possible to make an on-off loop circuit with common transistors?
Can I make a circuit that turns something like LED or similar small DC devices turn on for a second then turn off one second then on and loop like this with transistor only? I mean without using any ...
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3answers
65 views
Explanation of structure and function of a safety relay
I am reading a safety guide from Pilz. This guide contain a chapter about safety relays.
A circuit given in this guide is given below:
I know the purpose of all switches and buttons defined in it. ...
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1answer
41 views
230V Light switch to control intensity and drive two bulbs
I'm looking a way to improve a lighting solution.
The idea :
to use a basic electrical switch already present in my room wall (with Line switched by the toggle switch + Neutral not switched) to ...
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2answers
49 views
Is this design feasible? Door-open warning light circuit with safety interlock switch and general SPDT relay on wall voltage (120VAC)
I am trying to design a very simple system for my workplace that turns on a warning beacon light when a swinging door is opened. My current thinking is to use a non-contact magnetic safety interlock ...
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0answers
64 views
Momentary switch - press once needs to give 5 seconds of power [migrated]
Electronics is not my forte, so bear with me on the nomenclature.
Backstory
We have an old house and my wife bought me some old butler bells to get going as our door bell.
I found a motor which turns ...
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1answer
65 views
switching shape memory valves with microcontroller using NPN transistors
I am using a standard NPN transistor-as-a-switch set-up to use a Teensy 4.0 to switch a bunch of shape memory valves (valves controlled by a wire that changes shape when heated by a current). I have ...
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3answers
55 views
Reading a switch without a pull-up/pull-down resistor, for input into a script
The standard way to read a switch seems to be using a pull up/down resistor. I don't have one handy (I'm doing a one-off Raspberry Pi project while travelling and don't want to buy 100 resistors) - is ...
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26 views
How to write SPWM program for 5 level inverter in arduino
I am making an 5 level inverter using arduino so for that i have written simple arduino program for switching the mosfet but problem i am facing in this is it has low switching frequency so i want to ...
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4answers
83 views
Good design for reading a DIP Switch once
I want to read an 8bit DIP switch at MCU startup, after that it will be disregarded. I have enough pins on the MCU to read this directly. My question is; is it worth while to stop the power for the ...
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1answer
16 views
understanding the datasheet of a normally closed / changeover reed switch, for powering Arduino project
I am working on an Arduino project that should be sealed, with the possibility to switch off when the user wants. A solution I have seen on commercial products is the use of a Reed switch, normally ...
0
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1answer
65 views
Relay with built in manual switch
I have a question regarding the manual type relay switch shown in the picture.
I need relay with dual coil-latching, I thought of using avmomentary toggle SPDT to turn the relay on and off, but I will ...
0
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2answers
99 views
How to make an LED turn on if the input voltage is below 5V?
First of all I'm new to electronics. I am an automation engineer and a robotics integrator, so pretty specialized. Please be clear! Thanks all.
Context: PLC special circuit needs to stay at 5V ...
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41 views
Need help searching for a correct switch
I designed a PCB which uses switches. Sadly, I screwed up with the switching direction.
I bought these switches: Klick here. The position corresponds to the connection table below:
The problem is ...
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0answers
9 views
Keysight 34980A DAQ with 2 x 34922A Mux Modules
I am using Keysight 34980A Data Acquisition System with 34922A Multiplexer Modules. I read that there is availability of Internal Analog Buses from the connector at the rear of the mainframe with ...
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0answers
49 views
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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1answer
45 views
SPST pin configuration
I ordered a SPST switch (Through hole type) from distributors and also download the cad file for PCB layout from the same website. I am now confused with the pin configuration, in the footprints it ...
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2answers
158 views
How to activate one LED separately in a group of LEDs?
I want to activate one LED in a group of LEDs depending resistance varies linearly depending on the temperature.
I am using variable resistance that Controls how LEDs will light.
LED1 and LED 2 and ...
0
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2answers
63 views
Playing a sound when turning off a circuit
For my project, I am looking to have this (mock-up) circuit play a sound, e.g. the Windows XP shutdown sound, the moment it is powered off.
I have looked at capacitors, relays, opto-couplers, and a ...
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5answers
81 views
High side switch with N-FET
I know nothing about MOSFET, yet, so I'm fumbling in the dark here.
What I want to achieve is a high side switch using an N-FET. All guides I've been reading says "low side switch = NPN or N-FET&...
5
votes
3answers
1k views
Is it bad practice to always have a MOSFET on?
I am designing a circuit where I have a microcontroller driving
a four-channel logic level N MOSFET module. The simplest way for my circuit to work is to have the microcontroller run "HIGH" ...
3
votes
3answers
330 views
Add an LED to a low power line (heater thermostat switch)
I'm a beginner in circuit design and even if it applies to a real situation I'm doing this as an exercise.
After my thermostat broke some months ago I decided to replace it with an AC switch, which ...
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0answers
27 views
Arduino Leonardo and Limit Switch cuts serial monitor out for 5 seconds
I've been trying all afternoon to get this solved. I have an Arduino Leonardo and a limit switch connected as seen in the photos.
I've been running simple code through to check whether or not the ...
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1answer
61 views
“Disconnecting” an opamp from a potentiometer circuit
Last time I asked about changing a sensor (which is a potentiometer) output in various ways. I've decided to go with an opamp and circuit like this:
Now I'm looking for some device that will ...
2
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3answers
57 views
Dimmer for electric underfloor heating element [closed]
I'm new here and a mechanical engineer who knows just a little about electronics, so please excuse any ignorance.
We have electric underfloor heating in our kitchen. It seems the thermostatic probe ...
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2answers
82 views
Tact switches only work once
I am trying to do a digital clock using an Atmega8A, LCD display (2x16) and four tact switches.
Key number 1 is connected to pin PD2, number 2 to PD3, number 3 to PB6, number 4 to PB7.
When you press ...
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0answers
47 views
Power button does not work unless I short power pin to ground (then the power button works normally afterward)
The title might be confusing but I am confused as well, This is an old sony ta-808m amplifier.
initially, the issue was a broken power button I have replaced it with a new power button and I can ...
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1answer
55 views
Can I control the flow of a 12V power supply with a 4.5 volt power supply and a IRF3205 mosfet?
To start I am very much a beginner at electronics and am very limited in my tools.
I bought a IRF3205 mosfet a few days ago hoping that I could use it in a circuit I have where a 12V power supply at 1....
0
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1answer
50 views
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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0answers
37 views
MOSFET N-channel as switches in an AND gate
I thought I could use two BS170 transistors working as switches in series, to create logical AND functionality. My circuit is switching an LED with 1.5V of forward voltage and 10mA current set by a ...
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0answers
47 views
Low side MOSFET switch disconnecting charging
I have a problem with the design of low side MOSFET switch, that would be implemented in my electrical system to disconnect PV panels from a battery. This switch would be controlled by Controlling PCB....
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0answers
43 views
How to connect Sonoff Minir2 to this wiring?
My ultimate goal here is to connect a Sonoff Minir2 to the existing switch in my wall. This video allowed me to identify the switch (Busch-Jaeger) (https://www.youtube.com/watch?v=rV6tC_0wF50) and ...
5
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1answer
694 views
high-side circuit works?
What is the aim of 100ohm resistor between the micro-controller pin and the gate of the N-channel MOSFET?
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1answer
67 views
Switch 12v solenoid from 3v3 control signal
I am going in circles on the web and appreciate your help with this novice question, operate a solenoid with a mosfet (original idea, I know). I bought a Gravity DFR0457 to switch a 12V solenoid on ...
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2answers
47 views
Help with P channel FET not turning off
The circuit consists of an NRF52840 MCU controlling the power to a CO2 sensor. The output from the sensor goes to a buffer which then feeds it back to an analog input.
The MCU operates at 3.3V while ...
0
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2answers
60 views
Is it possible to make a one-off control FET switch circuit?
I was wondering if anyone knew any circuits such that when a small voltage is applied for a short duration (i.e. 500 ms), a switch transitions from the off-state to the on-state or vice versa for all ...
1
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1answer
44 views
Logic Converter driving logic level Mosfet Gate
I am wondering if anyone can comment on the feasibility of this circuit. My ultimate goal is to switch a 12V solenoid on and off using a 3.3V microcontroller, but I have had trouble so far. I want to ...
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1answer
52 views
Looking for solid state switch
I'm looking for a switch like element. I want to use it with DC, but intend to use it to charge and discharge a capacitor.
A triac would seemingly be perfect, however, I did a bunch of LTSpice ...
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1answer
26 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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1answer
41 views
Activate CE pin of a LDO voltage regulator with a momentary switch
The situation is as follows:
I have a 3.3V regulator that I would like to turn on and off by a momentary switch connected to its "CE" pin.
This regulator has an input from a 3.7V battery and ...
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0answers
24 views
Modular synth clock and sequencer control by relay
My modular synth master clock and sequencer don't communicate well. The need to have reset trigger for the sequencer has forced me to come up with a module that can send a control voltage to the clock'...
0
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1answer
108 views
FET analog switch example of “The Art Of Electronics”
I am currently reading the book "The Art of Electronics 3rd Edition". However I am having some difficulties to understand chapter "3.4.1 FET analog switch".
This section is about ...
