Questions tagged [switches]
Devices to interrupt or route a signal or power one of several ways.
2,867
questions
-1
votes
0answers
25 views
control circuit for MOSFETs
I am embedded systems engineer, I need some help related to issue in designing bidirectional buck boost converter. I have successfully designed and simulated the circuit on MATLAB, but now i need to ...
0
votes
1answer
57 views
Is using opto-couplers a good idea to switch in between two 80 pin connectors?
I am trying to implement a switch between two 80 pin connector outputs so that I can activate the desired connector. There are high speed signals to be taken into account.
Is using opto-couplers a ...
0
votes
1answer
30 views
Standard / Interpretation of dip switch on diagram
I've managed to get myself thoroughly confused now.
Given the following diagram for a dip switch, which way is up / on?
Do you read the above as:
1 = On
2,3,4 = Off
or as:
1 = Off
2,3,4 = On
0
votes
2answers
68 views
Turn off LED when submerged in water
I want to do a simple project where an LED turns off when it is submerged in water.
I thought this would be simple because when you short the two leads of an LED with wire, it just shorts the power ...
0
votes
3answers
93 views
How to make force sensitive resistor energy efficient?
I'm trying to sense when pressure stops being applied between two surfaces with a small embedded device connected to a coin battery smaller than 50mAh. All I care about is if they're separated or not (...
2
votes
0answers
69 views
MOSFET as reverse polarity protection and power switch too
We have a system where there is main power supply as well as a single cell Li-Ion battery (4.1V to 3.3V range we'll use) as a backup battery. Its a low cost and PCB area constrained product. The idea ...
0
votes
0answers
42 views
Multi-SIM card slot adapter
I want to make a multiple SIM card adapter for 10 SIM cards like in the images below:
Only one SIM card is active at a time. SIM cards can be switched using a DPDT switch.
SIM cards have six pins:
...
0
votes
2answers
57 views
Can I use a Dimmer switch or Ceiling fan speed switch to control wall panel heater?
Retired Civil Engineer here. Please answer so I can understand :)
I want to heat a small new bedroom in a converted garage with a 400 watt wall panel heater (resistance heat). Can I plug it into a ...
1
vote
1answer
63 views
Passive temperature limit supervision with electronic readout [closed]
I have a sensor component, which should not be heated over 60°C, otherwise it might start drifting for weeks. I want to supervise the temperature of the component, even if the device it is built in is ...
0
votes
3answers
99 views
Trying to control 20 loads using MOSFETs and Raspberry Pi GPIOs (NOT WORKING)
I have twenty 12V/450mA Solenoid Valves that I am trying to control using RFP30N06LE MOSFETs (n-type) as switches controlled by a Raspberry Pi 4B+.
The gate threshold voltage of the MOSFETs are ...
0
votes
1answer
84 views
switching an audio signal with a SPDT switch
Would you place the SPDT switch in front or behind the opamp?
the benefit now is the load stays equal on the source, 49K9 Ohm .. and the opamp is jobless.
but will the opamp cause noise (inverted)?
...
1
vote
1answer
63 views
How to choose the right MOSFET?
I am looking to use a MOSFET to switch a linear actuator on and off. There's nothing else on the circuit, just the switch and the actuator (and a Raspberry Pi to control the switch.)
The actuator ...
0
votes
2answers
87 views
Is there a solid state switch for DC circuits?
I am working on a noobie IoT project and I am stuck. Please help!
I bought an ESP32 microcontroller and I want to use it to activate a garage remote for a couple of seconds upon an HTTP request.
The (...
0
votes
0answers
41 views
Driving the Gate of an AC MOSFET Switch
I'm designing a bidirectional AC power switch using two source-to-source connected n-channel MOSFETs. Some restrictions apply to the design:
I want to use only standard components
The load must be ...
0
votes
0answers
33 views
Hardware for time-gated signal
Hey,
I am working on a design for an acoustic sensor,
I am applying an excitation field at a certain frequency (a) and recording the response of the sensor (b), however, for my application, I only ...
0
votes
1answer
53 views
Expected voltage on external gain resistor pre-amp
I want to build an amplifier with digitally controlled gain, using the THAT1510 pre-amp IC.
The IC provides two pins to set the gain, using resistors.
I want to switch between resistors with analog ...
-2
votes
1answer
77 views
Switch between 2 voltages
I want to switch between two input voltages separately. How can I do ig with a MOSFET or other things?
-2
votes
0answers
60 views
Does this type of characteristic of a latching switch have a name?
I bought a power adapter for my Raspberry Pi. The company reached out to me and asked me to give my feedback. I do have some feedback, as there are a few things I don't like. Wall warts are evil. ...
1
vote
1answer
44 views
Turning on/off esp8266 using a button
I have connected the five buttons to the analog pin of esp8266 as follows:
simulate this circuit – Schematic created using CircuitLab
I want to power on/off esp8266 when SW1 is pressed. Also ...
4
votes
5answers
697 views
High side switch for high voltage Nixie tube
Short version:
I am looking for a high side switch (20mA, 400V) circuit for half wave rectified mains, which I would be able to control with 5V GPUO.
Long version:
I am building a Nixie clock with ...
1
vote
1answer
108 views
How to fix this ABB MS325 circuit breaker?
I have couple broken training bench circuit breakers.
The broken part is the manual switch.
I uninstalled one and tried to open it. I was able to open the back side which contains metal connectors ...
0
votes
2answers
53 views
Removing broken switch from mains extraction fan for project - how to work out what the colored wires are
I have a kitchen extractor fan that I need for a scale model of Corsi-Rosenthal cube/box. The switch no longer works. It used to have a couple of speeds and a lamp. I'm looking to just wire it ...
0
votes
0answers
37 views
How to properly bias transistors used in switched capacitor circuits?
I am trying to simulate a switched capacitor circuit to implement a resistor.
First, I tried to do it with switches (top) figure. Then I tried to use MOS transistors in place of the switches.
Here's ...
1
vote
1answer
46 views
Using an NPN Transistor as a High Side Switch
I want to use the thermistor inside of a battery pack on the BQ25887 and on a GPIO pin on a microcontroller so that both the microcontroller and the charging IC can monitor the battery voltage. For ...
1
vote
3answers
189 views
Alternative to optocoupler in circuit design
I have designed a circuit that drives a +/- 20 to 30 peak to peak external signal received as an input to 16 different outputs.
Another requirement is that I have to be able to switch the state of ...
0
votes
0answers
43 views
DC pop with audio input switching in radio unit
I'm working with an older 1980s car stereo.
I added aux by cutting signal trace to tone control module (which goes: signal -> caps (100nF x2 in parallel, by design) -> tone control IC -> some ...
0
votes
2answers
40 views
Interpreting HP ratings of a pressure switch label?
I'm trying to interpret the voltage/HP table given on the badge of an air compressor pressure switch. Here's the badge:
What is confusing is what this table is actually supposed to be telling me. The ...
0
votes
1answer
55 views
3 phase inverter circuit mosfet burn out
I've designed a three-phase inverter for a hobby project that I'm working on and have had the board assembled. I'm new to this sort of stuff so learning as I go. I've attached the schematic. Initially ...
-1
votes
2answers
40 views
Hardware switch toggles for laptop modules
I intend to take the camera, microphone, wifi and bluetooth modules inside a laptop, determine which pin provides them with power and then reflow the solder and bend that pin up so it is not in ...
0
votes
1answer
63 views
Finding the Voltage and Current rating of a switch [closed]
I just bought a couple of switches at a garage sale. One looks like a SPST switch and the other seems to be a DPST switch. No where on these switches does it show a Voltage / Current rating. How can I ...
1
vote
1answer
50 views
Adding LED feedback to a source selection switch
I am working on creating an amplifier with multiple input sources. I have implemented a 3P4T rotary switch to be able to select the audio source among 4 different ones : RCA, Phono, and 2 digital ...
-1
votes
3answers
43 views
Time factor in specifying rating of electrical components
Ratings of electrical components like switches and sockets are marked in Amperes. Which means above this current the component is likely to fail (melt, burn, etc.), if run over some "considerable&...
0
votes
0answers
73 views
How to switch an AC signal
I have two AC signals, and I want to control their flow (either allow them to pass or open the circuit), therefore, I can imagine that the solution to my problem could be the same for both of these ...
2
votes
2answers
99 views
Modding popcorn popper: shut off heater while keeping fan on
So, I'm trying the age-old tactic of roasting coffee with a popcorn popper, and while it works, I would like to have better control over the heat applied in order to prolong the roasting. I've seen ...
0
votes
0answers
18 views
Selection functionality of FSTU3384 Bus Switch using N-MOSFET
I'm using FSTU3384 Bus Switch and I want it to perform the following function:
if SPI_ATP_CNTR# = 0 V then OE1 = high, OE2=low
if SPI_ATP_CNTR# = 3.3 V then OE1 = low, OE2=high
I'm using NDS335N N-...
-1
votes
1answer
42 views
I can't get this circuit to work - MOSFET PFV2 1BN50 not working [closed]
I can't get this circuit to work
Gate is connected to 3V.
Everything is connected and like seen on the image. Everything works except for my MOSFET. Why won't my MOSFET work?
I admit that I don't ...
2
votes
1answer
101 views
How to turn on LED with transistor without exposing a 5V conductor
I'm trying to turn on an LED using an NPN transistor as a switch. The catch is, the LED is at the end of a BNC cable, and in my current design, both the outer and inner BNC conductors are normally at ...
9
votes
4answers
1k views
Basic electronics: Transistor switch
I am new to electronics. I am reading this book called Practical Electronics for Inventors.
This is a portion about bipolar transistors from the book:
There are two things I don't get from this:
...
0
votes
2answers
94 views
Can I switch a 5V relay shield high straight from the power supply?
2I've bought a smoke alarm with a relay for my 3D printer. If the smoke alarm detects smoke it switches its internal relay. With this I thought I could switch off the printer.
The thing is that after ...
0
votes
0answers
70 views
Stray voltage on light fixture
I have installed a led panel on a previously existing light pole in my house. It has the feature of switching light colors if you flip the switch quickly. If the switch is left off for some time and ...
0
votes
3answers
95 views
BJT As a Switch. Efficency?
I needed a 2 digit display for a project and simply ordered a device 1, without the proper thought. To be fair I have learned a few things about 7 segment LED displays. Unfortunately I got one which ...
0
votes
1answer
60 views
Inverting 5V switch with minimal amount of current drain
I want to invert a 5V switch. I = when 5v(switch closed) is applied to the input 0v is received out of the output. I know a transistor can be used by having the switch short circuit the gate and this ...
0
votes
1answer
101 views
Rotary switch to momentary switch
I have a rotary step switch (something like that: https://www.tti.com/content/ttiinc/en/apps/part-detail.html?mfrShortname=C/K&partsNumber=A20615RNCQ&customerPartNumber=&minQty=1&...
0
votes
0answers
110 views
Basic ideas behind design of different topologies of DC-DC converter
I can analyse most of the DC-DC converter circuits that are mostly given in textbooks.
But how these complex topologies are designed for the first time i.e. what are the basic ideas that lead to ...
-1
votes
2answers
55 views
How to make a main switch toggle between two sockets (or bulbs)
Is it possible to simply (without relay) make a main switch toggle between two sockets or bulbs such that both of them are never ON or OFF at the same time?
I need to control two 12 and 9 volt DC ...
1
vote
0answers
66 views
Connect IR sensor switch to light up and turn fan on when detecting human
I want my store room light and fan to turn on or off automatically as people enter or leave the room. My current setup in the store room is a lighting control on off by the normal switch.
For the ...
0
votes
0answers
38 views
Isolating load from both sides with N-channel MOSFETS
I am trying to isolate a load both from the +, and the ground side and tried the circuit in the schematic below. I realize that the Q2 MOSFET should be p-channel, rather than n-channel, but I only had ...
0
votes
1answer
45 views
Are there any NFC tags that act as a switch or relay?
From what I understand there is always an active (reader/writer) and a passive (tag) NFC device.
Is it possible to have an NFC tag which is part of a circuit and works as a switch or a relay?
I would ...
0
votes
2answers
89 views
How to setup two different inputs to one output
Good morning. I am hoping to get some insight on a setup I am working on.
Current setup:
24V system. An area sensor when flagged by hand does two things.
First, it sends a signal to the network that ...
0
votes
2answers
65 views
Is it possible to read the value of a switch in another active circuit?
I have a magnetic lock with an integrated switch (NC when locked). The lock opens when supplied current and stays open even after the current is no longer supplied (until someone manually closes the ...
