Questions tagged [switches]
Devices to interrupt or route a signal or power one of several ways.
2,279
questions
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1answer
38 views
Switching buzzer on and off with two transistors
I want to make a simple water level indicator with tank full alarm as shown in the diagram. What I want to achieve is, when the tank is full to 100% and water is still flowing through the inlet pipe (...
0
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1answer
61 views
Light switch with 3 SPDT switches?
In the below circuit, I have two switches that can turn the light on or off from those two locations. Any 'switch' will turn the lights into the opposite position:
How could a circuit be made to ...
0
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2answers
31 views
Latching Switch Pinout
I'm planning on incorporating a latching switch into my design:
https://lcsc.com/product-detail/Electrical-Switches_XKB-Enterprise-XKB8080-Z_C318860.html I also found the corresponding datasheet: ...
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0answers
24 views
Three Phase Rectification using by Bi-directional N-MOS Switch
I have been trying to design three phase rectifier using by bi-directional N-Channel Mosfet . However, Non-isolated gate driver is not able to open and close U4, U8 and U12 on image. What kind of gate ...
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1answer
30 views
Looking for a micro slide switch On/Off guard that will work on a vintage RC transmitter
I have a very old New in the Box RC transmitter but some of the plastic items are a bit brittle.
Any ideas?
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1answer
56 views
Turn on LED with the opening of a switch
Hi I’d like a circuit that turns on an LED when the switch opens. I’ve made this so far, but it’s drawing too much current in the “off mode” that it will just drain my battery. Any ideas? I’ve seen ...
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1answer
41 views
Choosing the right MOSFET for 5V power relays
I am planning following circuit
PR_SIG: a 5V logic level coming from a uC
+5V: is powered trough a external power supply (max 10A)
Power_relay: 5V, needs 70mA to switch
My problem now is choosing ...
0
votes
1answer
33 views
How to flip LTspice voltage controlled switch so that it opens at threshold voltage? (versus close)
I am trying to figure out how to tell the VSWITCH of the LTspice program to open after it crosses the threshold voltage and close when it is below (with hysteresis). Normal behavior is that with Vt ...
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4answers
67 views
Pin Layout Unknown - 5-way navigational switch
Completely at a loss, been searching for a datasheet or anything to help for a cou0ple hours... So I came to the only place where I can usually find help
Does anyone know what the pin layout of this ...
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2answers
45 views
Wiring a 6 pin On/Off/On toggle switch (DC) 2 Pole
I bought a 2 pole 6 pin On/Off/On toggle switch that's for DC power, (25A 12V)
see here:
Toggle Switch
The only issue is that I have no idea how to wire it, as mentioned, it has labels on the back, 1,...
0
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2answers
51 views
Switch to turn off motor and another to turn the motor on
I have a DC motor that turns a gear which then has an arm that will hit a switch which turns the motor off.
Is there a way for me to build this without using a microcontroller?
Like I start the ...
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1answer
79 views
Is there a disadvantage to not having a power switch on a logic circuit?
I'm building a digital clock using 40xx series IC's. Currently you just plug it in and it's on. Are there any major drawbacks or disadvantages to not having an on/off switch?
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2answers
31 views
Is Capacitive/Clock Feedthrough signal-dependant?
I am wondering about the phenomenon of capacitive/clock feedthrough in a simple MOS device with a hold capacitor.
For example consider the following
If a parasitic Cgs appears, then surely Q = CV ...
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1answer
56 views
Keyboard switch removal problems
I recently put together a keyboard and had an issue with a couple switches so I decided to re-solder. I resoldered 2 and that fixed the issues but for this last one I started smelling something ...
0
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1answer
25 views
2 Pin Reed Switch Normally Closed Effect using BC547
I am very new to electronics. I am using a reed switch with 2 pin. Which acts as a switch near to magnet.
I want to keep the switch ON when magnet is not near and OFF when its near to magnet.
I ...
0
votes
1answer
60 views
Automatic watt/volt/amp switch
Google has failed me so I'm asking here.
I am looking for an automatic switch, which will change state depending on the number of Watts/Volts/Amps flowing through the circuit.
As an example: When ...
2
votes
1answer
80 views
Trying to wire up a couple dozen LED-lit toggle switches to an Arduino Mega
Update: Worked out a rough (I'm sure) schematic of the current idea for a smaller version of the circuit. A bit of info before the question;
The Arduino has a current cap of 200ma across all I/O pins,...
0
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4answers
53 views
2 / 4 quadrant switches - how can current have opposite direction to voltage?
I am learning about 1, 2 and 4 quadrant switches, used in inverters etc. I am however struggling to understand how, in the 2nd and 4th quadrant, the voltage can have an opposite direction to current. ...
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0answers
32 views
Single-wire (no neutral) smart switch supply? [duplicate]
I've been reading on home automation and found out there are smart switches that somehow manage to run without neutral wire, only live-in and live-out. And I started wondering how do they supply the ...
2
votes
3answers
159 views
Detecting switch closure
Any techniques/circuits/sensors that can determine the open/closed state of a set of contacts, independently of whatever power or signals are being switched by the contacts?
Obviously easy if there's ...
1
vote
2answers
51 views
Switch Individual Lights In LED Series
I am working on a hobby layout that will have LED lighting for some of the elements. I would like to individually switch LEDs in series on/off. I used ledcalc.com to generate the circuit diagram ...
0
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0answers
35 views
Reducing Common Mode Voltage at the ADC input
I need some help from you expert engineers.
I have to automatically measure VCE / IC and VBE / IB of a big bunch of transistors under specified collector and base voltages.
Since Vcin and Vbin can ...
0
votes
1answer
37 views
How can I create a series switch with a transistor for low power application
Hi,
I would like to make a switch that turns on/off input Vbattery to a analog (AIN) pin of uController used to measure battery level.
The uC also should control if the transistor is providing the ...
2
votes
1answer
118 views
Braking resistor design
The problem is quite articulated so I will start from a more generic description and get more specific as I go on.
I need help to design a braking resistor system for a fairly uncommon application. ...
0
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1answer
32 views
Double switch potentiometer
I'm looking for a type of potentiometer (ideally about 500k) that has a feelable click switch at both ends. I have only found ones with a single on/off switch. What's the term I need to look for?
1
vote
2answers
85 views
Switch that resets to 'on' after power loss
amateur Jack of all trades looking for something I'm not sure exists.
I have a mains lighting ring which means I can plug in lamps in my bedroom and turn them on at the door switch (if the lamps ...
0
votes
1answer
63 views
Any Problem With Two PMOS Sources Tied Together?
This is my third revision of this supply switching circuit. Do you guys see any problem with this revision?
This is a circuit to switch from disposable lithium battery to USB power when the device is ...
0
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0answers
68 views
Is there a way to switch between circuits without a relay?
So I'm trying to create a mobile phone charger inside an Altoids mint can, It uses two Panasonic NCR18650BD which have a discharge of 10amps. Anyways, I have it set up in parallel. It uses a zener ...
0
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2answers
78 views
Two 10ampere switch instead of one 16 ampere
I want to use two 10 ampere switchs for my 16amp appliance.What I will do is divide the input wire of the appliance into two,pass it from two individual 10 ampere switch and then recombine them and ...
0
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0answers
56 views
How can I disconnect some wire connections automatically when a specific one is disconnected?
I have a selector switch that can select a 5V digital signal to the output or terminal C of the encoder to the output. It's simple so far. But my application requires that when I select digital signal ...
1
vote
1answer
50 views
15 second switching circuit
I am designing a circuit that receives a signal from a motion sensor, and then turns on a light for 15 seconds. I have a rough idea on how to make the circuit, but I am also curious what are the ...
1
vote
0answers
82 views
What is the Umlaut Symbol in this relay?
I'm wondering if the reoccurring "Umlaut" (Ö) symbol in a manual for a process controller that I'm referencing is an actual electronic representation of something, if so what, or if this process ...
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0answers
54 views
Socket with an embedded relay for microcontroller
I'm working on a project to test device charging. The idea would be to use a micro to turn the socket the charger is plugged into on and off. I need 10 of them so I was wondering if there is an off ...
1
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2answers
106 views
Connecting push button to microcontroller
I want to connect a simple push button to a microcontroller and record the time I press the button. Would this work or do I need to put a resistor in between?
If yes why?
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3answers
65 views
How can I set a wire to one of 3 voltages from a simple digital controller (e.g. Raspberry Pi)?
Here's my problem. I have a device to control that needs to always have one of three voltages applied to it: 5V, or 6V, or 7V. And I need to be able to programmatically switch between them.
What I ...
13
votes
3answers
3k views
Logic inside a 3 or 4 way light switch?
I'm trying to understand what is the logic or mechanism used in 3 way or 4 way switches, in order for all swtches to work so that no matter the position of each switch, the lights go on or off without ...
0
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1answer
30 views
Do fuse tap turn off with kill switch?
Do fuse box connected circuits turn on and off with the vehicle?
I’m trying to connect my Arduino to my motorbike using a fuse tap to the fuse box. I want my circuit to turn on and off with the bike. ...
0
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1answer
47 views
RGB LED strip presets controlled by a switch via 2-pin connector
First, I apologize if my terminology is incorrect. I am out of my element, but trying to figure this out.
I bought a cheap PC case in Korea, and it included an RGB LED strip on the front of the case ...
2
votes
1answer
109 views
Designing a circuit with a “short-lived” switch with 555 IC
i am very new to electrical engineering and designing circuits and there is a particular project that i am working on that involves using a switch and a 555IC timer.
So basically my desired output ...
0
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2answers
51 views
Separating power depending on voltage
I just started working on a computer science project that requires me to do some hardware stuff, but I am a complete noob most of it. For a part of the project I need to be able to forward a current ...
0
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1answer
43 views
What happens when we discharge a capacitor through a SCR which we leave open?
I am wondering what would happen when we discharge a capacitor, by using a SCR, through a coil and we leave a current applied to the gate of the SCR. The coil should generate a ‘reverse’ current right?...
0
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2answers
59 views
Increase resistance to turn on a light bulb
I’m wondering if it is possible to use a potentiometer to turn on/off a lightbulb in a binary manner.
I’m thinking high resistance = light on. Low resistance = light off. Is there such a circuit? ...
0
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3answers
53 views
How to wire a 12V DPST switch?
I have this 12V DPST switch that I want to wire, to make or break both Negative and Positive cable to open or close a solenoid valve.
I would say:
3. (+) to battery
4. (-) to battery
2. (+) to load
1....
2
votes
1answer
59 views
How do I get this PFET to switch off when G=5V (high)
What am I missing (and why) to allow this PFET to switch on and off? I'm new to this but am learning. The circuit is part of a larger schematic I am working on. Once I get this working I can insert it ...
0
votes
1answer
47 views
Control current to one of two loads on PCB
I am currently working on a project where 2 batteries powers multiple components on a board. A raspberry pi, 2 thrusters and a winch. Each device is powered via the battery and a buck converter. The ...
0
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2answers
114 views
“Normally closed” switch: does it use more power than a “Normally open” for a low-power battery-powered ATtiny project?
I have a "normally closed" magnetic door sensor, that I'd like to use with an ATtiny microcontroller.
Does a "normally closed" switch use more power than a "normally open" switch?
i.e. since the ...
0
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2answers
56 views
What connector to use to non-permanently fix wires to large switch terminals?
I have a rather old rotary switch I want to use in a project. I want to connect wires to the terminals but would prefer not to solder directly to the switch. What connector is good for this?
The ...
0
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1answer
27 views
Replacing momentary button/switch on monitor control panel
There is a button that toggle inputs on my monitor and the very thin top dome/bubble came off and not I can't really press it to work, though if I use a flat head screwdriver (the diameter of the ...
0
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1answer
36 views
What type of switches are used by impulse relays?
I am looking for a switch for impulse relay. These switches are bi-stable switches and return to the original state after being pressed. Hobby push button switches do not cut it for me because I need ...
1
vote
1answer
70 views
Simple low power rising and falling edge enabled circuit
I am working on a project where I use an esp8266 and a reed switch sensor (NO), this is powered by a battery so I need a low power circuit that can turn on the esp8266 when the state of the reed ...
