Switching

Hi, I am new to electronics although I am an electrician by trade. I need to know if there is a way to switch a load electronically. It needs to switch from one load to another. I also need to know if there is a way to monitor current flow so that it switches when it hits a specified current. Thanks in advance Edd

Topic by eddcole   |  last reply


A self switching switch? Answered

Does any one know a switch that switches or toggles to another output after each one has had 1 turn  

Question by techxpert   |  last reply


Latching switch to a momentary switch?

Basically I want to make a toggle switch to trigger a circuit from on or off. its hard to explain but when the switch is in the on position it triggers a circuit momentarily. When I switch the switch off i need it to trigger the circuit again. Its for a 4 wheel drive module for my bronco and its momentary push buttons that I want t o convert to a toggle switch.

Question by catsnw   |  last reply


USB to switch?

I am building a backlit keyboard, and I wanted to hook it up to a switch. How would I make it from the USB, or the default connector, to a switch?

Topic by Exploitation   |  last reply


Momentary switches

Hi, Just wanted to know if a momentary switch (normally open) could be used as a on/off switch with out using a relay.  thanks in advance :D

Topic by Nanow   |  last reply


led switch

My dad is redoing his basement and he wants to have a panel of switches with leds above them.  so that when the switch is on the led above it is on to.  does anyone know how to do this?

Topic by tic tac man   |  last reply


switch help

I'm doing a school contest with a car which requires a toggle switch. I'm gtoing to use a dcd to dc converter to give me an edge. The only problem is that it needs to be a momentary switch. whenever you push the switch down it goes on. Whenever you push it down again it turns off. Any idea for a circuit so that a spdt (3 pins) toggle switch will act like a momentary switch each time it's flicked for a time like a second?

Topic by guyfrom7up   |  last reply


Switch Timer

Good day, Please i have 2 bulbs/leds, one is green and the other is red. I want to put a time switch between them so that after 10 minutes the red switch off and the green lights up and vice versa till i switch it off. So do you know of any switch that i can use for that purpose, that will operate under 12v, like 5v. Please thanks

Topic by Don Amada   |  last reply


infrared switch

I was wondering if they make infrared activated switches, so its like wireless. if they do where can I get them, I've seen those 10x things but they don't really appeal to me.

Topic by Jordo   |  last reply


Wireless switch? Answered

I need to learn how to build a wireless switch that can turn something on like lets say a coilgun. I need it to be wireless so that i can stand back behind cover and fire my coilgun and do other things without harming myself or my classmates.

Question by budhaztm   |  last reply


Switching Circuit

Hi, I want to build a Auto-Switching circuit. I would appreciate if you could help me on circuit. Sorry for my ignorance in circuit design. There are two power sources A and B. The A is 12v and B is 3v.I would be utilizing the power from A only when B is turned On. So an auto switching circuit is required in this scenario. The circuit should sense if B is On, if so it should let A On.

Topic by arunsun   |  last reply


switch for a coilgun Answered

What is the minimum amperage rating needed for the fire switch and what will happen if u use something lower, like a 20a light switch? also how much one would cost would be nice to. i have heard that 40 or 50 A will work, but i would like to use something smaller, easyer to find, and more affordable. any help would be nice.

Question by the mechanical engineer   |  last reply


Current switch? Answered

I have some solar panels that produce 3v at 175ma. I was wondering if i could somehow make a switch to have it turn on when the panels are producing at least 100ma. Maybe also a switch for 150ma too :) Any ideas?? If additional voltage is needed it shouldn't be a problem :) Thanks!

Question by astroboy907   |  last reply


Switch problem

I have a question for the electronics gurus out there. I have a circuit that I want to activate for a set length of time (I'm using a 555 timer for this) when a door is closed and not operate again until the door is opened and then closed again.  I'm an electronics newbie.  The one-shot 555 circuits I have seen rely on using a momentary switch, but in this case the switch will remain closed as long as the door is so the circuit will remain active.  Are there switches available that will close and open while remaining fully depressed?  Or is there an equivalent circuit that will work with an ordinary momentary switch? Two more things:  the door is very small so the solution must be small; also the circuit will run on batteries so the solution can't be a power drain. Thanks in advance, I hope this makes sense to someone! Kerry

Topic by number8wire   |  last reply


Ultraviolet Switch?

I am trying to figure out a way to make a switch that is activated by a UV light. I have looked all over the web and cannot find a thing on this subject. The reason that I am trying to do this is that I recently purchased a Sonic Screwdriver that  has a IV light in the end and I was wanting to make it turn on/off things with the push of a button.

Question by Ben Torok   |  last reply


electronic switch

Hi, i'm a bit new to electronics. I was wondering if its possible to turn on the flow of current by another electrical signal. Yes, i know about transistors and relays but these switches turn off as soon as the second current is stopped, how to make this change in switch permanent, i'll be precise, i'm working on a laser alarm system, and it works fine, but the thing is that when i block the laser, sure the buzzer goes off, but when the obstruction is moved, the buzzer turns off, how can this be kept on until turned off manually by a switch. i know it must be quite simple but i dont know, please help thanks

Topic by walee    |  last reply


Switch button

I have connect Arduino with wave shield and 2 switch buttons to play wave when the buttons are pressed but it played it automatically with out any press and it repeat I don't now why .. void loop() {   trackNum = findGPSLatLng();   Serial.println(trackNum);     // Get if a button was pushed   buttonState1 = digitalRead(buttonPin0); buttonState2 = digitalRead(buttonPin1);        if(buttonState1 == HIGH && previous1 == LOW && millis() - time > debounce)   {     audioSelectFlag = 1;   }   else if(buttonState2 == HIGH && previous2 == LOW && millis() - time > debounce)   {    audioSelectFlag = 2;   } time = millis();     //  here is the wave files to play   switch (trackNum) {     case 5:     if(audioSelectFlag == 1  || audioSelectFlag == 2)         playcomplete("1.WAV");         break;         case 1:       if(audioSelectFlag == 1)         playcomplete("1.WAV");       else if(audioSelectFlag == 2)         playcomplete("1b.WAV");       break;     case 2:       if(audioSelectFlag == 1)         playcomplete("2a.WAV");       else if(audioSelectFlag == 2)         playcomplete("2b.WAV");       break;     case 3:       if(audioSelectFlag == 1)         playcomplete("3a.WAV");       else if(audioSelectFlag == 2)         playcomplete("3b.WAV");       break;   } }

Question by moonwa   |  last reply


On and Off Switch?

I have a kiln that I need maintained at a certain temperature for an extended period of time (9 hours). Problem is  the kiln I got doesn't maintain its temp, it just constantly supplies heat until it would kill itself. Making me sit there for 9 hours turning it on and off exactly once a min. Obviously this is a problem... there is a physical on and off switch where maybe I can rig up some timer to hit it for me? Otherwise maybe there is a way to modify the wall outlet to supply power 1 min on, 1 min off? Any suggestions would help, thanks :D  http://www.clay-king.com/images/quickfriec.jpg

Question by ReconIII   |  last reply


Transistor switching problem

I am having trouble using transistors to switch a some LEDs, I have 5 LEDs in parallel being switched by one transistor but each LED is indervidually switched by another transistor. I have given each LED its own resistor and the problem I am having is that when all LEDs are on each LED gets dimmer then if only one was on. I don't really understand why this is happening but I'm not 100% comfortable with transistors and I have probably done something stupid. I have attached a image of how I have wired it up with only two LEDs

Topic by camlv   |  last reply



Stupidly simple circuit question - answered.

OK, so I accidentally volunteered to make an X-factor type buzzer board for a school event. Three switches.  Throw each switch, in any order, a light comes on. Throw the third switch, in any order, and a buzzer and/or fourth light comes on. It's a simple circuit.  Must be.  Just a few transistors, LEDs and batteries. But, I just cannot work it out! I should be able to sketch it out in my sleep, but my brain will simply not cooperate. I'd prefer to use a single DC power supply, up to 12V (multiple LEDs to make the lights brighter), but I have several I can use if required. Dimensions are not important, I'll just change the lengths of wires. But, can you help with the circuit? >K< Thank you, Lemonie!

Topic by Kiteman   |  last reply


URGENT!!!Reply fast!!!BC 547 switching? Answered

My school exhibition's tomorrow and I need to do something urgent.There's a 7 VDC supply which is converted to 5 VDC by a voltage regulator(both have a common negative terminal).I need a BC 547 to act as a switch and complete the circuit of a device connected to the 7 volt circuit when the 5 volts is used as a signal and sent to the transistor.To put it in another way-The device needs to run on 7 volts when a 5 volt signal is sent to the BC547.I've got about 4 hours of time before I go to sleep(actually forced to!)and the exhibition's tomorrow morning!!!

Question by Adarsh_tronix   |  last reply


I need help with arduino

Hi everyone,  I am playing around with arduino, and I got in trouble with the push button. Is there any possibilities to switch in between the LED patterns. I got the coding for three difference LED pattern here. I want to switch from 1st to the 2nd , and from the 2nd to the third by pressing the button. Thank you so much, I really appreciate your help. These are my LED patterns

Topic by tompham89 


How do I switch a Push button Switch to a toggle switch?

I bought EL wire and the power is a push button switch and would like to know how i could change it to a toggle switch also if anyone knows how to change it from battery powered to powered by the car ild greatly appreciate it for that I was thinking of using a fuse tap though

Question by alphashark45   |  last reply



How to tell what current-limiting resistor to use Answered

I'm having my Arduino Leonardo substitute a few buttons in a device. In the buttons, one pin connects to ground with the other going to a microcontroller. I figured I could connect an NPN transistor in parallel, with the emitter to ground, the collector to the microcontroller, and the base to a resistor and my Arduino. How do I choose this resistor? Every guide I found involves getting the current load, and I don't know how to do that. I'm thinking I can just put in a 10k resistor and be fine, but I want to make sure. Thanks for any help

Question by 4lifenerdfighter   |  last reply


Modifying a DC-DC boost circuit

I'm building a circuit that would run off roughly 7v and convert it to 12v using the LM2577 (LINK). the datasheet (LINK) provides an example circuit that will output 12v @ 800mA. I need a little more power than that. around 1.25 A. my question is that if the 100mH inductor was replaced with a larger one. say a 150mH one, would that increase the current output? i would also replace the 680uF cap with a bigger one to reduce ripple. FYI the LM2577 is rated to convert 3.5v-40v to 12v. any information or direction would be appreciated picture is from the national semiconductor datasheet page 3

Question by stapler117   |  last reply


wiring a dpdt switch like a dpst switch

I need a DPST rotary switch so that i can turn on two circuits at once but the closest i've been able to find with appropriate ratings is a DPDT switch, is it possible to wire it up to my circuits in such a way that it works like a DPST switch? I've attached an example diagram i found of a DPDT switch, if i was to disconnect the lamp from pin 1 and the buzzer from pin 2 would the first position of the switch become Off and the second position become On powering the LED and speaker? also assuming that the LED and speaker only connected back to their respective batteries and not to each other, could i attach a low voltage battery to pin 3 for the LED and a higher voltage battery to pin 4 for the speaker without causing damage?

Topic by ambientvoid   |  last reply


Replace mechanical switch with electrical switch or replay

0I have a remote controller for a portable heater, and working on a small project to be able to control the fan on/off from an arduino with Bluetooh HM-10 module. I thought a solenoid might work by mounting on top of the remote but it doesnt have enough force, I want to remove/desolder the mechanical button and figure out a way to control it without the switch but kind dont really know what circuit I should use, kind of just learning how to use arduino.Images of remote and button traces below.Any idea how I could wire this up to arduino via some switch/relay circuit? Any circuit design / schematic would be helpful(See pics attached)

Topic by hydrocarbonz   |  last reply


How to use a 555 timer to switch a switch? Answered

I was thinking about making an intervalometer circuit for time lapse use on cameras. I was thinking of using this link https://www.instructables.com/id/Time-Lapse-Intervalometer-for-SLRs-with-555-timer-/ . I was thinking of adding a 22uf cap, as well as the normal 220uf cap, and then adding a 2200 uf cap, for a highly flexible range of time (ranging from a few seconds to about an hour), choosable by switch. I am starting to run into trouble at the camera connection itself. While i am fine with a cable, i would rather go with a wired remote, and using it to do the equivalent of pushing the remote buttons (instead of going through the cable itself). So i need a way to connect the two switch points electronically, rather than mechanically. Also is there a way to have it focus first, then take the photo? This circuit would also be good for cameras that do not have remote connectors, just go in to the camera and solder the switch points up, then hook them to this circuit. Would also work with a wireless remote. Hook it to the remotes switch and go from there. Just need a little help finding out what to do to get it to work the way i want to :) Thanks

Question by astroboy907   |  last reply


trigger momentary switch/button via switch

What i try to accomplish is very simple. my Airconditioner has a Push button (momentary switch) to turn it off and on. but the Thermostat brings permanent power it it want the A/C to be on. i could make a simple delay setup for 1 sec. or so to trigger a relay but then i can't be sure its really on or of. how can i ensure its turned on via an timer relay safely if the control wire has power ? any recomentation on existing products or schematics ? i can check the "real status" via other parts on the airconditioner easy .. i just need a way to ensure ON and OFF based on the command line is High or Low ..  any ideas ? 

Topic by nullx8   |  last reply


LT Spice Switches?

I have a simple question... If anyone here knows about the program LTSpice, is it possible to create switches that are manual, like pushbutton switches, spdt/dpst/etc., not automatic switches?

Question by 101yummYYummy101   |  last reply


Infinite Rotary Switch? Answered

I'm looking for the search term I need to find a "Rotary Switch" That spins very smooth and will keep spinning indefinitely like a volume control switch.

Question by bradleynelson102   |  last reply


USB Light Switch

I have a spare light switch and I want to convert it to play a song when I flip the switch. How could I do that?

Topic by wisconsinrules88   |  last reply


Remotely activated switch? Answered

Howdy, I'm workin on a project with LEDs and I wanna know if there is a switch I can remotely activate?

Question by sf49ers   |  last reply


Need help with switches.

II have two switches. One momentary and one latching. Both have leds and want to wire them so that the LEDs turn on or off when the latching switch is activated. Please see pictures as they are not regular 2 or 3 poled switches. Thanks.

Topic by bastafari   |  last reply


k and a slide switch

I got a k and a slide switch and i dont know how to use it to connect the wires to it.

Topic by southautomatic   |  last reply


Wireless DPDT Switch?

How can I make a wireless DPDT Switch for my robot. I'll be using a receiver and transmitter system but have no idea how to control the DPDT Switch using that.

Question by Shantam Sridev 


Cat5 Changeover Switch?

Is there anyway to make a switch that switches between cat5 connections? For example, if I have 5 wires running to a rack with some switches in it, and wire one goes bad, I want to be able to turn the switch and then it will start using wire number two instead. How would I go about doing this? Any help would be appreciated :) -Tyler

Topic by tyler9613 


Is there a switch that reverses polarites? Answered

 Is there or do I need to get complicated?

Question by Chromatica   |  last reply


Question about switches...

I am very new to electrical projects. Please be nice. Does it matter which side is positive or negative on a switch?

Topic by Soileau   |  last reply


Switch with led inside?

Hi, I want to add this switch to my circuit. I currently have a switch with no led light inside. If I add this to my circuit, will I need resistors for my switch? and will I need to redo all the resistors for my circuit? I currently have 4 LEDs with 680ohms resistors on the circuit.  thanks

Question by RoboRay   |  last reply


Motion Sensitive Switch

I'm trying to come up with a switch that activates when it is moved. Ultimately it would connected to a sound device and a small sample would be played every time the unit is picked up. Any suggestions on how I should go about doing this?

Topic by hectma   |  last reply


Book light switch?

Hi. I have a shelf, directly attached to the wall with a light switch at the back (see attached diagram). I'd like to use a tilting-out book as an on/off switch a la cliche mystery secret-room-door-opener. Any ideas for how to do this? Oh...just found this example: http://www.vespoe.com/blightdesign/shop/secret-passageway-switch Thanks!

Topic by samhandwich   |  last reply


How to wire a switch

Hi I would like to know how this switch should be wired up. I am using it on a drill press. It has 2 relays 1/ nc zb2-be102 2/ no zb2-be101. Any help would be much appreciated. Thanks ratjack

Topic by ratjack   |  last reply


Touch Lamp Switch?

Is there such a thing as a switch that is touch sensitive so just a tap will activate it. I want to make a lamp out of an empty glass coke bottle and i want to be able to touch the cap to activate it. Im looking for a small piece of silver metal that will match the cap so i can place it on top, OR a way to make the actual cap the switch. Thanks!

Topic by um0123 


Does this switch exist? Answered

It may just be my google-fu failing me, but I can't find switch I am sure must exist: A sliding switch with reversing (DC) polarity. At one end of the slider, power is full "forward".  Slide the controller, and power decreases.  Reach the centre, and power is zero/off.  Slide past the centre, and power increases again, but with reversed polarity, ie in reverse.

Question by Kiteman   |  last reply


LED on/off switch? Answered

I'm looking for an instructable that would point me in the direction of how to make an led red/green light for when my roomate is allowed to come in (Socks are no longer working)

Question by JustinH16   |  last reply


What are internal switches? Answered

I've been searching out parts on digikey, and noticed that a lot of the power/audio jacks had an "internal switch", with three conductors and four contacts.  I've never heard of these before, and none of the datasheets were helpful, nor ten minutes of googling, in educating me.  So what are these mysterious internal switches?  I presume they somehow switch between two states depending on if there's a plug in the jack.  But why is this helpful or necessary?  And more importantly, how does this affect how to wire the jack?

Question by Skidion   |  last reply


Drill battery Switch

Hello! i got a car horn with an motor, the motor is rated 12 Volts so i got a 12 volt drill battery since im not going to install it on a car. However, i got a problem... My plan is to mount 2 switches, a Keyswitch and a push buttom switch. so i bough that .. However it made me think if the small switches can take the Power of the drill batt. I have no idea how many AMps a drill batt got, and the key switch is rated 0,5A / 250 VAC and i the push/switch one is a standart like this https://elextra.dk/images/large/8011.jpg .. Now do you think i need a other switch or will i smelt them by pluggin the Drill batt on ?

Topic by Kong markus   |  last reply