Questions tagged [switches]
Devices to interrupt or route a signal or power one of several ways.
2,776
questions
0
votes
1answer
46 views
Is this a 2-way switch or what?
Are there switches realizing these 3 states, or at least the 1st and 2nd?:
They could be switching DC or single-phase AC. I am trying to find out if they exist, how they are called and if there are ...
0
votes
1answer
22 views
How to wire a single input for two separate chargers e-bike
I'm currently designing my own e-moped for university (named ‘enduro 器’); I am currently going through the wiring and I am in need of some assistance.
(refer to the image above) I want to be able to ...
0
votes
2answers
78 views
How to cheaply build a latching relay system to disable a circuit until power is cycled?
This is my first post here. I have an aftermarket backup sensor that needs to be disabled when I back a trailer. I want to be able to push a button to disable it, but have it be automatically re-...
2
votes
3answers
136 views
Using op-amp and diode switch to drain capacitors – how to limit current?
I want to use a diode switch to drain a capacitor. The switch in the circuit is opened and closed regularly. The op-amp will flip between ground potential and 5V at its output. When the output is low, ...
0
votes
0answers
34 views
Programmable momentary switch for motorized desk desk leg with elcetronic stop
We're building motorised tables with 1 leg. Currently the manufacturer can only do either:
2 buttons up and down switch, that need to be pressed to start the motor and pressed again to stop the motor....
0
votes
2answers
77 views
Help identifying circuitry diagram
Now first and foremost, I know absolutely nothing about circuitry - joined an computer science chatroom and they couldn't help, I have cross referenced the symbols to the internet to try and ...
0
votes
0answers
43 views
How to build a MOSFET switch to control a coolbox 12 V 8 A? [closed]
I have a coolbox in the boat and for certain reasons I want to control its power on/off with a relay type device. There are two important objectives: 1) keeping the circuit closed should consume as ...
0
votes
2answers
59 views
Can I use an AC rated momentary switch as a PC power button?
I was looking to make a custom button to power my PC (I needed something which was a bit more custom than the traditional push buttons for PCs (it's not important)) and I came across these: https://...
0
votes
1answer
75 views
How do I select the transistors for this circuit?
I have no background in electrical engineering at all, and only bought my first breadboard this week. I'm still completely new to this and just trying it out.
I'm trying do drive an 12V actuator, ...
0
votes
2answers
34 views
Switch on and off an electronic device within a time range e.g: 8am to 3pm
i am wondering if anyone know how to adjust an electronic device so it can work on a specific timeframe, I have a water pump, I would like to make it work only within a determined time range, for ...
0
votes
2answers
41 views
Timer switch suggestions?
I have a simple security/alarm system I built for my carport after a thief took advantage of me.
It simply has a strobe light and an extremely loud siren, using photoelectric sensors. When the sensors ...
0
votes
0answers
40 views
LED Driver IC to charge batteries
I would like to use the ZXLD1350 LED driver IC to provide constant current to some NiMH batteries to charge them.
However the negative terminal of the LEDs go to an inductor instead of ground.
My aim ...
0
votes
2answers
52 views
Current sensing relay that momentarily closes contact each time state changes
I have a 240V dust collector that I manually switch on and off using a one-button wireless remote. The dust collector is connected to several machines.
I'd like to use a current sensing relay to ...
0
votes
0answers
29 views
Will this MUX work for my application?
I'm having a hard time determining if this mux will work for my application:
https://www.mouser.com/datasheet/2/256/MAX14752-MAX14753-1515255.pdf
I'm trying to use 2 of these together in a PCB I'm ...
0
votes
1answer
59 views
Why does this switch go both to ground AND to the input pin?
Here is a really simple circuit, that I don't quite understand:
https://microcontrollerslab.com/wp-content/uploads/2019/03/Push-button-interfacing-with-ESP32.jpg
I understand the LED portion. What I ...
1
vote
1answer
50 views
Selecting 36V, 12V and 9V from 3 different PSUs
currently i am designing a system in a machine. One of the feature is it can select power supply between 36V (overvoltage), 12V and 9V (under-voltage). Max current would be 300mA @ 12, while 9V which ...
4
votes
1answer
64 views
How to have periodical repetition of customized pulse waveform in LT Spice?
I have a customized Pulse pattern and I would like to have it in repetition. Does anyone know how we can establish that in LT spice?
0
votes
1answer
76 views
I'm having trouble finding an available switch to match a schematic. Is it possible? [closed]
I'm having trouble finding a 4P3T switch for the circuit below, credited to David Mikeska, which I believe to be described as follows in a contact configuration table you'd commonly see on a datasheet....
0
votes
1answer
47 views
Transistor as a switch from point A to point B
[
Hello, I'm curious how I could replace the momentary switch with a transistor in this scenario. Would I connect the left side of of the button to the collector and pins 2 and 6 to the emitter, then ...
-1
votes
2answers
94 views
4x4 keyboard matrix - why no pull down resistors?
I found many schematics out there for a 4x4 keyboard/switch matrix, both with and without diodes.
Yet I don't get it. If one doesn't add pull-down resistors, rows 1 to 4 will all be floating.
Can ...
0
votes
1answer
125 views
SATA hard drive selection by mechanical switch
I want to have a toggle switch to toggle between two hard disk drives. Only one should be connected at any given time.
The best possible solution for what I want to achieve is to toggle the power ...
1
vote
1answer
54 views
Can two On-Off valves be independently or concurrently switched with my hardware?
I am having a ton of fogginess today thinking of a way to switch a couple On-Off valves with the hardware I'd like to use. When I say 'On-Off', I mean the valves pictured below, where applying voltage ...
1
vote
1answer
51 views
Terminology for components found in Kitchen Timer
Apologies if this is a duplicate, by definition I'm not sure what to search for.
I took apart a kitchen timer and found a few things I'd like to learn about, but couldn't find the right terminology to ...
2
votes
1answer
61 views
Problem Implementing high side P channel mosfet power source selector
I have build the above circuit on a breadboard and it is almost working but not quite. I've spent a number of hours on the problem to no avail. My background is not electrical but I've been building ...
0
votes
0answers
59 views
Using N channel MOSFET as switch
I have many N-channel MOSFET and i want to know is there a way to use as an alternative of P-channel (Q1) in this circuit?
This circuit is responsible of switch between battery and power source.
-3
votes
3answers
94 views
How To Make A Switch Close When Another Switch Close? [closed]
I want to use a rotary switch to switch between filters which I believe will give me different frequencies. But the problem is when I connect the positive feedback to the other filters too, naturally, ...
1
vote
2answers
54 views
Current Dependent Switch
I have a 24v DC circuit; I need a contact that breaks the positive line if the current in the negative line differs from the current in the positive line. So if the negative line has become broken or ...
0
votes
1answer
61 views
Can I connect a wall switch to DC?
simulate this circuit – Schematic created using CircuitLab
I am making an air blower with a Kingwin RL4B-B1402512H fan. Can I use the wall switch, and if so, can I use the dimmer as well?
0
votes
1answer
45 views
nRF52840 with optocoupler and mosfet
I would like to make a switch which will be able to switch on/off 12-60V low current devices using nRF52840, optocoupler and mosfet.
I found this schematic and my idea was just to adjust R1 because ...
2
votes
1answer
63 views
Reed Switches - Good brand, stuck in the closed position problem
I'm doing a project with an Arduino pro mini 3.3v that uses internal pull-up to detect changes on a reed switch sensor. I'm buying the reed sensors from AliExpress, and most of the time they work OK ...
1
vote
0answers
41 views
DC step-up converter, slecting 2 different Vout with SPDT switch
I want to modify a DC-DC step-up converter that uses a single potentiometer that sets the voltage to use a single SPDT switch where I can select the output voltage during operation without turning the ...
0
votes
1answer
45 views
How do you control a control wire?
I am reading about electromechanical relays used in the first computers and I am told that the mechanical relay is closed and opened by an electromagnetic field generated by a coil on a control wire ...
2
votes
3answers
103 views
Switch design for shorting the power control pins?
I have been struggling to design this switch for a while and I would appreciate any help.
Problem Background:
I'm designing a power system for a submersible, using the Mini-box OpenUPS battery ...
0
votes
0answers
35 views
Reverse polarity protection and enable function
The purpose of the schematic is, on the one hand, to provide reverse polarity protection. On the other hand, the switch has the function of enabling the flow of current to the load.
These are the ...
0
votes
1answer
30 views
Deviation in the switch current in a flyback converter
This is the current waveform of the switch and the Vds of the MOSFET.
Ideally, the current should fall off in a normal fashion with the switch turns off.
Here, the current fall stops and becomes flat ...
1
vote
2answers
84 views
Why are standalone MOSFETs and transistors preferred over integrated load switches?
As a novice to EE concepts who's trying to apply it to Arduino projects, I was doing hours of research on how to electronically switch another higher current (or voltage) device/component/subsystem on ...
0
votes
2answers
62 views
NPN transistor switch with load at emitter pin
I found a schematic with a 55 timer driving two transistors, each of which switches an LED (see below).
When the 555 output is low, LED1 is OFF and LED2 is ON.
When the 555 output is high, LED1 is ON ...
1
vote
1answer
133 views
What are the momentary switches in Dangerous Music Source?
I have a Dangerous Music Source. One of the momentary push buttons started to fail (I have to push it so hard to work that I'm afraid of breaking something else... I tried to re-solder it, but it ...
0
votes
0answers
26 views
MOSFET triode small-signal modeling
TL;DR: Why do seemingly all treatments of MOSFET small-signal operation ignore the nonzero \$g_m\$ contribution in triode? Is the implicit assumption here that if the MOSFET is operated in triode then ...
0
votes
1answer
38 views
Connecting more than one input of IC together
I'm interested in using SLG7NT402V Load Switch and I was wondering if it's okay to connect pins 3,4 together and 6,5 together.
what is the difference between this and using only one pin?
does this ...
-1
votes
1answer
64 views
Switch lamp problem [closed]
I have the answer to the following problem, but I am not sure how they got it. Please explain:
Four identical incandescent light bulbs L1, L2, L3, L4, and a battery are connected as shown on the ...
1
vote
1answer
43 views
Touch switch for hanging lamp (touching metal bar): Ideas?
A few years ago, we have bought an IKEA Glimt hanging lamp that operates with halogen lamps. It has a "touch dim" functionality, so when a person touches the metal bar of the lamp, it dims (...
0
votes
1answer
85 views
How to turn on and off with certain frequency (for example 20 Hz) a simple circuit?
I'm trying to connect a battery of 9 V to the secondary coil in a transformer (220 V - 12 V), but I would like to turn on and of this connection with certain frequency in order to see in a ...
0
votes
2answers
82 views
Did I understand this diagram correctly? How do you put a load on a positive wire?
Sorry I mixed up the two diagrams, I thought both diagrams were using FETs on the right side.
I am trying to turn on a 5V separate power source with a 3.3V GPIO output.
I have two separate circuits, ...
0
votes
1answer
53 views
How to control the output current in when using a transistor as a switch?
Assuming that I have the following circuit where I use a transistor as a switch:
When the transistor is not active Vout will be equal to the Vcc and the current will become very high right? So if I ...
1
vote
1answer
65 views
An OR power supply circuit
consider the following circuit:
This image shows a simple "diode OR" power supply switch. I am trying to derive the cheapest circuit to obtain this functionality (the given circuit does not ...
0
votes
2answers
39 views
Maybe a JK latch? Need some help
complete electronics novice here unfortunately. Please bear with me.
I'm after some kind of switch (latch/flip-flop?) that will interrupt a momentary switch held in its 'on' position when another ...
0
votes
4answers
57 views
Single pole triple throw analog passthrough
I have a circuit that will simulate a device.
The device in question normally communicates by adding/removing resistance from a generated signal, the source of the signal will then measure the voltage ...
0
votes
3answers
72 views
NL17SZ74 D-Flip Flop circuit doesn't work!
I've been having trouble with what should be a really simple Momentary-to-Latch D flip flop switch circuit.
Basically:
I want the momentary switch PUSH to set the CP (Clock Pulse) Pin Low and on ...
0
votes
0answers
37 views
Driving an array of resistive loads on high side with as little parts as possible
I'm trying to switch an array of resistive loads at 12V as fast as possible using least amount of parts due to limited board space. I have tried to find sourcing darlington transistor pairs but they ...
