Devices to interrupt or route a signal or power one of several ways.
1
vote
1answer
65 views
Common Gate Level Shifter
I am in the need for a high-side load switch and came up with the following schematic. High-Side voltage levels and current vary between 5-12V / 2 A max. The high-side PMOS (SI5509DC) is rated for 20V ...
2
votes
1answer
51 views
Switching between circuits, transistor-based SPDT?
I want to use a piezo buzzer alternatively as a sound detector and as a sound emitter, on the same circuit (be gentle, this is my first attempt to electronics since the university long years ago).
I ...
0
votes
1answer
46 views
Ethernet switch selection [closed]
I want to build a small cluster out of beaglebone black computers, this toys support only 100Mbps ethernet and the question is what kind of switch would be the best to connect them all?
I thought of ...
2
votes
1answer
61 views
Are there any issues in using traditional switches with an Arduino?
I'm using an Arduino Micro for my project.
I'm planning on using two switches as digital inputs. One is for an override switch and a setting switch, but their functions aren't particularly important.
...
1
vote
2answers
63 views
IC buffer like 4066 with 8 or 16 switches
I have a computer and two monitors. I want to build a device so that I can switch between to monitors. I would use buffers (like 4066) and a microcontroller. Is there any buffer like 4066 with 16 or 8 ...
0
votes
1answer
54 views
Switch and Pushbutton Combo
In a circuit I'm designing I want the user to be able to switch the power off and on (with an SPST style switch), as well as depress a push-button (push-to-break) that will temporarily disable the ...
1
vote
2answers
68 views
Digitally Switching a Single Source into 128 Channels
I have a device I'm building that uses a single high-precision current source (driven by a DAC for various arbitrary waveforms) to drive one of 128 channels. The current level will be on the order of ...
1
vote
2answers
76 views
What's a simpler way to switch between power sources?
I want to make a device that allows the user to switch between two different power sources (a wall mount and batteries).
I could perform this circuit using two DPDT switches, but I would need to ...
0
votes
2answers
51 views
Turn a mains AC load off when another one is ON
What would be a way to turn OFF load A (10 amps) as soon as load B (10 amps as well) is turned ON, faster than the time it takes for a circuit breaker to trip (~15 ms)?
Something like a voltage ...
1
vote
1answer
54 views
Help dimensioning mosfet as switch with high current
I have the same problem as the guy in this question, but in this case the input voltage varies from 20 volts to 28 volts.
I would like a current of 20A to flow through the mosfet without it getting ...
-3
votes
1answer
132 views
Push button switch plus 10 LED's
How to insert a push button switch in this circuit?
6 Volt Power Supply 10 LED's 10 resistors.
I can do it with just one resistor and 10 LED's.
I have a 6 pin push button switch.
Here's my circuit ...
0
votes
1answer
74 views
why and how do I use a capacitor in a switch circuit？
I have seen many designs of switch circuit:
I know that a capacitor will help anti-shake but I realy do not know how i can anti-shake. Does it work like a decoupling capacitor or a low-pass RC ...
0
votes
2answers
134 views
Raspberry Pi GPIO
I need to make a connection between the "Device"'s 2 wires using a Raspberry Pi, but I am unsure how to go about doing this (and I don't want to just play about with it and get it wrong as I might ...
3
votes
2answers
67 views
Which way will I place a momentary Tactile switch in a solderless breadboard
Well I am a beginner in electronics. So, I have some 4 pin tactile switches and I am confused about placing them in the breadboard. Here is the poorly drawn photo of the two ways of placing by me. ...
3
votes
3answers
135 views
Switching 12V with an active low 5V signal
I’m trying to switch 12V (max 30mA) with a signal from a MCU that I’d prefer to be active low (so the output voltage is 12V when the control signal is 0V, and 0V when the control signal is 5V).
Since ...
3
votes
0answers
71 views
Turning OFF the grill when the espresso maker is ON
These are the variables to this problem:
We have two 120 volt appliances:
- an espresso machine (draws 8 amps)
- and a grill (draws 12 amps).
The grill is ON all the time (it actually stops heating ...
2
votes
2answers
159 views
Building a wireless keyboard (preferably with a kit)
This is the project that spawned these earlier questions.
I'd like to create my own keyboard. Functionally it's going to be a keyboard, but visually it's going to bear more semblance to a joystick ...
4
votes
3answers
97 views
Energy efficient one button on/off with extra function
(Old) cellphones have a button to turn it on (when off), end a call (when on, short press) or turn it off (when on, long press).
I need something similar for a microcontroller. The device is ...
7
votes
4answers
141 views
Can I achieve a one shot button without a 555?
I have a complex circuit, but my problem only relates to one small part.
I have a relay, which is energised by pulling the low side low using an NPN. I would like a pushbutton to operate the ...
5
votes
1answer
115 views
Circuit that switches one led ore all three
For an analog photo enlarger (yep, that vintage stuff) I own, I would like to build my own lightsource. For the prototype I found 3 colored super bright led panels they use 12V
The problem is that ...
0
votes
0answers
29 views
over temperature and current limiting question about a power switch: BTS5235
I am designing a cuircuit with BTS5235-a smart power switch from infineon.this is the datasheet of BTS5235
I get realy confused about its datasheet.
1.problem about VDS(Voltage at power transistor). ...
3
votes
1answer
84 views
Electrical properties of keyboard keys
I'm looking to hack together a keyboard by taking an existing keyboard and connecting it to switches that I'll assemble separately.
What I want to know: What should be the electrical properties of ...
1
vote
1answer
82 views
Wiring a switch to toggle both usb power and external power on Arduino
I have a 5v Arduino Pro Micro. I am using it to run a series of motors. I am controlling it through the USB port. The USB power doesn't supply enough current to power the motors, so I am using a 9v ...
3
votes
2answers
83 views
Best practice to switch +V or GND connection?
Consider LAMP1 and LAMP2 in the simple example circuit below:
Which is the "better" practice, using the switching component ...
4
votes
3answers
164 views
Why does grounding my switch cause the fuse to blow?
I'm working on restoring an old ATV, and I'm having a bit of trouble with the wiring. When I got the ATV it was missing the ignition switch, so I decided to replace it with this awesome looking ...
0
votes
1answer
56 views
Any Ideas for Understand one of the 3 phases has powered
I want to ask you about a situation which i couldnt find the exact solution or better way to do the job.
The situation is i have 3 phase (380V) induction motor and one of the phases to the motor had a ...
1
vote
2answers
75 views
Max switch current
I am in the process of designing my first PCB and I need to include some switches to open or close a circuit with a max current of 500mA at 5v. I have found a DIP switch that I want to include on the ...
2
votes
1answer
102 views
Diode selection for truck wiring light application
I need to know what diode I need for a light set up I am working on.
The main current flow through the diode is going to be 9v going to power a 55watt roughly ??? amp bulb. There will be ocassional ...
1
vote
1answer
79 views
Default-on, latch-off, MOSFET power switch
I'd like to build a low-battery circuit. It should default on when first connected, but if a particular signal goes high for a small amount of time (say, 10 microseconds,) then it should turn off, and ...
3
votes
3answers
311 views
MOSFET as a switch?
In the picture shown, can "Output" be controlled to be 0V or 12V based on "Control"?
Will be Drain and Source the way it is connected be a problem?
2
votes
2answers
153 views
How to switch between a solar panel and battery?
A 12v battery is being charged from a solar panel. When battery is 12v solar panel is disconnected from battery and connect the load with battery. And again solar panel is connected with battery when ...
4
votes
3answers
74 views
Creating a Sequenced Array of 3 Mosfets with Adjustable Timings
I am comfortable with rudimentary 555 circuits and other basics, but I have something a little bit beyond me now.
I need to have three separate mosfets A, B, and C all turn on and off in sequence. I ...
1
vote
5answers
318 views
MOSFET or Transistor for using as switch for audio signals
I was wondering which component is better for using as voltage controlled switch for audio signals (e.g. music signal from mp3 player). Should I use MOSFETs or transistors? The max rail voltage is ...
3
votes
2answers
299 views
BJTs versus (MOS)FET to switch a load from a microcontroller
I would like to know what are the reasons for choosing bipolar junction transistor (BJT) versus a field-effect transistor (FET) (MOSFET or a JFET) to switch a load from a microcontroller. In our ...
1
vote
2answers
96 views
easiest way to detect a switch change using an arduino
I have a pinball machine thats an old electro mechanical type. I want to add LED's and do some fancy programming on an Arduino to animate the lights according to the score value of whatever target ...
0
votes
2answers
60 views
2 x 4:1 Switch or Demultiplexer
I have 8 LED's and I am trying to turn 2 on at a time. My voltage source is 5V and the LED's require up to 200 mA current. I am finding quite a few demultiplex chips that are 2x4:1 but most of them ...
2
votes
2answers
149 views
Is this a 5V to 3.3V level converter?
Need to repair a legacy system that has been discontinued and am confused by the PNP based circuit below.
The input signal (max. freq = 20Khz) is applied at IN and is active low. It's TTL level.
It ...
1
vote
1answer
66 views
Connecting three led transformers
I'm a furniture maker and I built a unit which used three circuits of led lights.
Each circuit's transformer has a max output of 2.5 A.
I would like to use a single switch to put between the plug and ...
6
votes
4answers
260 views
Protecting Microcontroller Input Pins from Soft Power Switch
I'm working on a soft power switch for a microcontroller where a momentary switch can turn the circuit on (including microcontroller), and then when the switch is pushed a second time, the ...
2
votes
2answers
79 views
What is the best way to switch between different ranges when designing a multimeter using microcontroller?
We are developing a multimeter using a PIC18 microcontroller and we are searching for the best method to switch between different ranges in multimeter with the smallest possible amount of switching ...
0
votes
2answers
110 views
Representing a four-way light switch
I've found symbols in this explanation for a four way switch but I can't find that symbol in any of the online circuit-drawing tools I've looked at.
The best alternate representation I've come up ...
0
votes
1answer
73 views
I think I am looking for a specific DC relay switch
I am looking for a switch not sure what kind though.
let me explain:
I have two sources one creating DC 12v, second one creating around 6v DC.
One source works for about 12 hours each day then ...
0
votes
2answers
74 views
iCMOS analog switches and multiplexers
Does anyone have any experience with Analog Devices iCMOS high voltage analog switches or multiplexers like the ADG1434 or ADG1411?
The specs for iCMOS sound very impressive. But they've been ...
3
votes
1answer
234 views
Is it possible to use just a capacitor to debounce a button?
I have been wondering: why cannot you just hook up a capacitor to a button to debounce it? I have been figuring out how to reduce the work my microprocessor has to do, but I have very limited space on ...
6
votes
2answers
144 views
How do these modern power buttons on devices work
In the older days and still now we have buttons where one way is off and the other way is on, its mechanically built to connect or disconnect an electric path physically.
On modern devices like ...
1
vote
1answer
73 views
Turning the PN junction of JFET on?
I am going to use a N channel JFET as a normally-ON switch. I am wondering if it would cause any problem in the long term reliability having the PN junction forward-biased. In other words, would it be ...
0
votes
0answers
87 views
Controlling Wall Switch
I intend to control the operation of a wall switch through an arduino board.
I'm wondering if there's a good way to wire into this switch to do so, or if I need to go farther back.
Here's the switch ...
7
votes
3answers
407 views
Pull Switches - why so expensive
I would like to use a pull switch as a trigger for an alarm that I'm building. When the switch is triggered it will turn on a siren and potentially a strobe light. I've found plenty of options out ...
-5
votes
1answer
60 views
How to build a switch that is turned on with small voltage? [closed]
I want build a switch that is switched ON with 1 or 2 volts. A small circuit would be fine.
2
votes
0answers
222 views
Arduino - Trigger an iPhone's touch screen with no human interaction
I'm trying to replicate part of this experiment. Specifically, I want to touch the screen with a cable and some aluminum foil whenever I send a signal from an Arduino pin. From the blog post linked ...
