Questions tagged [switches]
Devices to interrupt or route a signal or power one of several ways.
3,042
questions
0
votes
0
answers
41
views
Is it possible to create crosspoint(crossbar) switches with FPGA?
we have 4 USB type C ports in one of our projects. We are using TPS65988 and TUSB546A-DCI for PD control and crossing USB signals. We want to take design to the next level with the crosspoint switch, ...
- 33
5
votes
2
answers
524
views
How does a basic SPST analog switch differ from an ordinary switch?
In the test circuit I'm building there is a 1 kHz PWM signal passing through a DG467. As far as I know, the DG467 was placed there to interrupt the signal if needed, like an electronic on/off button ...
- 59
0
votes
0
answers
71
views
Which type of limit/microswitch is this?
Which type/model of switch is this? It is used as a limit switch for a gear rail. Found inside the cinema filter mechanism for Epson TW-9300 projector. The other one has degraded and is now missing ...
- 136
0
votes
0
answers
19
views
AC MCB or DC MCB
I'm using MCBs on one of my projects involving a battery pack. Is it safe to connect using an AC MCB (Brand Legrand India) for switching between the states (on/off)?
Vbat < 100 V, expected current &...
- 17
1
vote
2
answers
57
views
Best switch type to turn off the mains voltage to electronics [closed]
Basically I am making a reflow plate, that requires mains voltage for the heating plate. I have a basic knowledge of mains voltage and am just trying to make the product as safe as possible, by adding ...
- 23
0
votes
0
answers
27
views
Possible faults for significant kVA differences in switch cabinets?
Would there be any faults if any on the cables, either nearby or near the switch cabinet if there is a significant kVA difference say 2x-3x? For example, for 3 phase wiring, 2 cables having 1000 kVA ...
- 145
2
votes
4
answers
103
views
Switch on when voltage detected
I'm adding a Google Home Mini to an antique floor radio. I don't want to toss the original components, so I'm planning on wiring the speaker to the Google Mini and want to add lights that come on in ...
- 23
0
votes
1
answer
31
views
VAC/VDC Control input voltage in Solid state relay
I have been trying to understand the datasheet of solid state relays from different manufacturers and I was not much familiar with solid state relays. A confusion arose when I came to see the control ...
-1
votes
0
answers
34
views
SFP power interrupt issue
I need help debugging a network issue related to an SFP module. I have an SFP module connected to an FPGA. Normally, I can ping and send/receive UDP packets without any issues. However, sometimes (...
- 29
0
votes
1
answer
44
views
Circuit to turn relay on/off based on button press
I'm using a CPU case to enclose a diy project and I'm looking to see if I can turn the main circuits power supply on using the on/off switch in the front panel of the case. The button needs a circuit ...
- 123
0
votes
1
answer
61
views
What kind of switch to use for output power in a variable bench power supply
I am some what new to electronics. I have been designing a variable bench power supply from an ATX.
I want to add two output power switches: One to the low current low voltage variable output rail (...
- 1
0
votes
1
answer
44
views
Schematic Review: PIN diode switch driver
I've designed a PIN diode RF switch driver, specifically to drive HP33000 series switches. Unfortunately, these are very old, and not much documentation exists, so I'd like to ask for advice from ...
- 53
0
votes
1
answer
63
views
What is the purpose of capacitors in 6.302.0x propeller circuit
In this course on edx it introduced the assembling of this circuit for the labs
However, I can't totally understand the purpose of some components in the circuit (shown below)
What is the purpose of ...
- 455
0
votes
3
answers
66
views
Discharge lithium ion battery to a specific state of charge
I am trying to make a circuit to discharge a 4s battery pack to 30% state of charge to ship it safely.
I will be doing this from time to time and would like to discharge the packs rapidly (around an ...
- 41
1
vote
3
answers
129
views
Issue with NPN transistor as a switch
I am working on this simple circuit, which uses a BC547 transistor to switch ON a LED when trigged by a switch.
The scenario is the switch is connected after a long wire about 20 meters.
Issue: When ...
- 149
0
votes
1
answer
36
views
Proteus design buzzer quiz circuit
I am trying to design a 12-people buzzer quiz game.
I just want to use LEDs and AND and NOT gates, using one switch for reset.
The problem is that after designing it all the odd LEDs or even LEDs ...
- 13
1
vote
3
answers
72
views
Component Placement Strategy for Regulator and Controller
I am reading this interesting document from TI PCB Layout Considerations for Switchers
It explains the issue of the return path for high di/dt currents in regulators. To summarize my understanding, it ...
- 187
1
vote
3
answers
110
views
16A AC rated switch contacts welding with 36V battery and capacitor. Can a series inductor fix this?
I have an old Black&Decker battery powered mower that uses a 36 volt SLA battery pack. The original motor failed catastrophically and I now have a 24 VDC motor adapted to fit. I added a PWM buck ...
- 1,131
0
votes
0
answers
20
views
Looking for an automatic switch to keep my two solar systems completely separate? [duplicate]
Here is a picture of my Queensland, Australian setup.
My 4kW off-grid system needs to be completely separate from the house 3kW solar system, and also cannot touch the Energex meter box at all, ...
- 11
0
votes
1
answer
151
views
Relay Open and close switch button Automatically
I have a very simple circuit consists of battery - load (lamp) - button (on-off)
I want to a very simple + cheap ( without arduino or micro controller) way to open and close circuit automatically ...
- 141
1
vote
1
answer
21
views
Looking for a simple circuit to switch power to IR LED's at night (2A @ 12 volts)
I'm looking for a simple and cheap way to switch power to a few hi-current IR led's at night. So some sort of photo detector and a solid-state or traditional relay. Unless there's a single-component ...
- 129
0
votes
1
answer
33
views
Controlling ADC (on/off) with microcontroller
I'm designing a PCB. I want to turn the ADS1120 ADC off/on using the SAMD21G microcontroller. The ADC has two power inputs, 3.3V analog and 3.3V digital. The 3.3V analog is connected to an LDO that ...
0
votes
2
answers
104
views
How do you disconnect a circuit briefly when a button is pressed?
I'm trying to add a reset button to my circuit which will temporarily cut the power to the circuit when a button is pressed.
I thought about using a transistor, and short-circuiting the gate to ground ...
- 1,105
0
votes
1
answer
57
views
Powering two loads from either one or two sources
Both loads need to be powered at all times - V1 or V2 can be either both present or only one of them. Does this circuit look like it is going to make it happen?
Instead of M1 and M2 there will ...
- 866
5
votes
6
answers
3k
views
Running 15 amps through a 10 amp switch to power a 13 amp circuit?
I am very new to electrical engineering so I have very little experience. I am currently working on a project that has me using a 24 VDC 15 amp power supply. I was given a switch that is rated for 24 ...
- 59
2
votes
2
answers
56
views
Control AC load via relay with DC trigger?
The headlight of my motorcycle is AC powered via stator.
I want to switch between Hi/Low beam using a single pole double throw (SPDT) NC relay.
Power to pin 30 (AC)
Ground to pin 85 (?)
Trigger to pin ...
- 23
5
votes
4
answers
1k
views
How are switch ratings determined?
As the only functionality of a switch is to interrupt the flow of electricity, it acts like a small resistor right?
Lets say that we have a switch that its max ratings are 3A/250V AC. So if we connect ...
- 63
0
votes
4
answers
143
views
Bi-directional current source based on MOSFET or IGBT [closed]
I am studying a bi-directional current source based on precision difference amplifiers and the MOSFETs, which is described on the website https://www.edn.com/simple-precise-bi-directional-current-...
- 11
0
votes
1
answer
30
views
What is the MCU-Pinmode equivalent of a button-press to ground in this scenario?
The more I think about it the more I confuse myself... In the attached circuit if I want to simulate the effect of SW1 (or SW2) closing to ground how do I set the MCU-pin? Connect to Terminal 2 of ...
- 135
1
vote
3
answers
75
views
Transistor in pull-down "switch" application
What is the transistor circuit which acts as a SPST switch given: 1) +24vdc, 2) ground, 3) a "floating" pin that the switch takes to ground when triggered (there is no "load")? I ...
- 11
1
vote
1
answer
35
views
Is there a way to predict the VDC rating of a relay in function of its VAC rating?
I need a 36VDC 20A DPDT (c.f. answer to some other question I had) - resistive load mostly -, but can't find any. I have found candidate relays though, that have been tested at 28VDC 20A, 470VAC 20A, ...
- 1,380
0
votes
4
answers
135
views
How to detect welded contacts of a redundant relay? (for reliable high-current e-Stop)
I want to switch ON/OFF a load with an e-Stop backup - the issue is that the load is 20ADC.
So the load is switched by a suitable relay (SPST-NO), which is itself controlled by the ON/OFF switch in ...
- 1,380
1
vote
2
answers
83
views
Automatic voltage selection using SPDT relay
I'm working on a design with two voltage inputs and I need to give priority to one of the two inputs when both are plugged simultaneously. Both must also work individually.
the first input (V1) is ...
- 13
0
votes
0
answers
25
views
Different types of ceiling fan speed controllers
I have a new Hunter ceiling fan that came with a 4 speed wireless controller built in, including a 5uf capacitor and a 10uf capacitor inside. I removed the wireless controller and wired the motor ...
- 101
1
vote
1
answer
36
views
Question about Disconnect Switches
I'm looking at an electrical construction drawing and I just keep forgetting what the disconnect switch notations mean. Refer to the attached image. This is what I'm assuming: the number in the first ...
5
votes
1
answer
152
views
What's inside this RF absorptive modulator?
I'm trying to understand how a vintage(?) HP 33000 series absorptive modulator works. Unfortunately, I don't have access to the detailed datasheets, so all I've been able to find is this document, ...
- 53
1
vote
2
answers
103
views
Can I digitally open a circuit?
As a basis for a low power project, I want to render the useless machine not useless
https://www.youtube.com/watch?v=Z86V_ICUCD4
A useless machine is a simple mechanism that powers up when a switch is ...
- 123
0
votes
1
answer
104
views
What's this type of switch called?
What is the exact name of this type of switch?
It comes from a digital piano sustain pedal. Most of these cheap sustain pedals seem to use the same size switch. I'd like to replace this particular ...
- 11
0
votes
0
answers
42
views
Physical switch for reconfiguring an Ethernet connection
I have an Ethernet connected device that I need to move from one switch to another from time to time.
I want to implement a way to do this remotely using an electronic or even physical switch.
Is it ...
- 1
0
votes
0
answers
40
views
potential free output signal with AC as input (no mechanical relay)
Here's what I'm trying to do:
I have a a bunch of 24vac actuators running of a 24vac XFR. The actuators themselves are controlled by a thermostat. What I need is a isolated 0v signal when any of them ...
- 55
1
vote
1
answer
32
views
Thermocouple actuated switch
So first of all, I'm a mechanical engineer and a terrible electrical engineer.
I'm trying to build a failsafe for a heating element. This heater has an integrated k-type thermocouple and is limited to ...
- 11
2
votes
0
answers
29
views
When using a square wave inverter is arcing a problem when installing a switch
A perfect square wave switches immediately from a high positive voltage to a high negative voltage. Does this mean that a switch installed in a circuit powered by a square wave power inverter will ...
0
votes
1
answer
79
views
Signal switching in oscilloscope
I have an oscilloscope with two probes and a few repetitive tests to run on quite a few boards.
The first probe is always connected to the same test point, but the second probe should be connected to ...
- 101
0
votes
2
answers
132
views
Port expander with high side switch ground dilemma
I have a design wherein the basic idea is to control individual LED strings and dim (analog dimming) them using Pi Pico via I2C interface.
This board is the LED driver which will be connected to the ...
- 19
1
vote
0
answers
78
views
Confusion In Fanout of Logic Circuit and Transistor
Fanout:-Maximum Gate we connect to output of any Logic gate.
so there is limited number of gate we connect the output of Logic Gate.hence there is some minimum condition required for operation of ...
- 174
-1
votes
1
answer
60
views
How to get rid of transition spike in LT Spice
I have created the below circuit that simulates the current characteristics for a contactor. However I am getting this huge spike when the switches transitiion.
Can someone help to prevent this spike ...
- 1,383
0
votes
1
answer
69
views
How to distinguish which buttons have fixed on/off positions similar to a flashlight button?
I'm searching for a button/switch similar to one on a common flashlight: you click the button to turn the light on, then eventually click it again to turn off. Example clip of Button (Adafruit / ...
- 115
-1
votes
1
answer
64
views
MOSFET circuit to trigger timer. Any additional safety additions to circuit required?
I want to trigger a timer (Omron H3DK-M2) using a circuit based on a MOSFET as a switch.
The data sheet for the timer states
"When using a 24 VDC power supply voltage there will be an inrush ...
- 1
0
votes
0
answers
35
views
Transistor Switch Output Current Increasing
I'm using a BJT switch to send a 48 V, 2.5 mA signal (thanks for all the help in the past!). I've been tuning the resistance value I need to output 2.5 mA and noticed that the output current is ...
- 33
1
vote
1
answer
62
views
An over- and under-voltage protection system
How can the block diagram below operate as an over and under voltage protection system?
I thought it will work as follows:
A step-down transformer is used to bring down the alternating current supply ...
- 11