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Limiting Switch? Answered

I don't have time to do the research right now, but I am going to make a projector mount that comes out f the ceiling, does anyone know how to set it up so that when it reaches the bottom the motor auto stops. It will be a two way switch, one for up position and one for down position.

Question by jj.inc    |  last reply


Wiring help

Hi guys I am need of some advice and help if possible, I will try and explain as clear as I can. I have a lockup which I have modified to use locking bolts on a motor and I have a swipe card reader and pcb which when swiped it fires the output to power the motor (6v) which works perfect for 6 seconds of the locking bolts going in and out. I am looking for a way so when the locking bolts go to the locked position it hits some kind of limit switch and stops there (which I have done in the past) but then I want to be able to swipe my card to open the bolts and when it gets to he open position it hits another limit switch and stays open until I want to swipe and close the locking bolts. I don't want this to be timed I need this to stop on open and closed position but able to operate when either is pressed, Can this be done in anyway?

Topic by sherpin2000    |  last reply


Vacuum Pump Limit Switch System

Hey Everyone... I'm Alive! I've just been really busy with my senior design project :DSo today I acquired ToolUsingAnimal's vacuum pump on loan. I'm going to be doing some vacuum bagging.... To prevent his pump from blowing out, I need to make a limit switch so the pump shuts down when it reaches full vacuum and then turns back on if some of the vacuum bleeds of somewhere.So the method I cooked up today was to use a syringe with a weight. The weight will pull the syringe open and close a micro switch that turns the compressor on. If there's vacuum, the plunger will be fully retracted and the switch will be open (off position). This method will cost me all of $5 or so (10 cents for the syringe and $4 for the switch).I was just doing some math on how much weight I'll need for different syringe sizes - and it's totally plausible (we're talking less than a pound to 3 pounds depending on syringe diameter).Question - any other suggestions or blatantly obvious/easy/cheap solutions? I know this sounds Rube Golbergian, but it's not nearly as complicated as it sounds (or looks) :D Emphasis on cheap, I just put in an order for roughly $2000 of materials and supplies!

Topic by trebuchet03    |  last reply


wiring limit switches on a linear actuator

I am trying to wiring two limit switches onto a linear actuator. One to stop the extend stroke but will allow you to retract the actuator. The other limit switch will stop the retract stroke but allow you to extend the actuator. The actuator is installed on a door I need it to stop on the extend stroke and the retract stroke so it doesn't damage anything. I have an LACT8-500A actuator and the company doesn't make a limit kit for the adctuator.

Topic by youaintwrong    |  last reply


RGB Color change with limit switch

Hello all. I'm new to the community and I'm working on a project where I need an LED strip to change from a static color (red) to another color (white) for a second or two and back to its static color (red) and be repeatable everytime the switch is pressed. What is the best course of action? I'm super trash at writing code for arduino, but would that be a good solution?

Question by ewolsitruc    |  last reply


6volt powering locking bolts but need diagram to wire limit switches

Hi guys I am need of some advice and help if possible, I will try and explain as clear as I can. I have a lockup which I have modified to use locking bolts on a motor and I have a swipe card reader and pcb which when swiped it fires the output to power the motor (6v) which works perfect for 6 seconds of the locking bolts going in and out. I am looking for a way so when the locking bolts go to the locked position it hits some kind of limit switch and stops there (which I have done in the past) but then I want to be able to swipe my card to open the bolts and when it gets to he open position it hits another limit switch and stays open until I want to swipe and close the locking bolts. I don't want this to be timed I need this to stop on open and closed position but able to operate when either is pressed, Can this be done in anyway?

Topic by sherpin2000    |  last reply


how do I connect limit switches to a sliding door system controlled by Visual Basic software?

The limit switch system must detect if the door is open and if it is, the whole system must be disabled.

Question by khutso    |  last reply


Inrush current limiting resistor size?

I am building an application where LED strip lights will be powered off a 12V DC battery and switched on and off using a magnetic reed switch. I've been finding that the reed switch often fails to turn off when the magnet is removed. Searching on the net suggests this is because the contacts are getting fused by a large inrush current and the suggested fix is to wire a resistor in series to prevent this - so far so good but I cannot find anywhere guidance on the rating of the resistor I should use - at least guidance I can understand - as far as I can tell a resistor as low as 1 ohm may be required but not sure if I have got this correct - anyone know? Thanks

Question by SeaF1    |  last reply


How to connect limit switch, motor & timer?

Hi..can anyone help me how to connect limit switch, dc motor & timer?..i want the motor stop & the timer is on when the limit switch is touched..after the timer is off the motor automatically on again..can anyone help me?

Question by MuhammadI304  


dc motor with limit switches wireing help

I have a 1998 Trans am that has power windows. The problem is the doors are fiber glass and the motors create a lot of force on the doors creating problems. What I want to do is put a limit switch at the top and bottom of the window travel.        I'm using the factory switch that sends +12 volts in the up or down direction   I have a dc motor, limit switches and dpdt relays. I need to know how to wire it all together. If you could draw a picture that shows all wires from switch to relays to micro switches to motor that would be best. Thank you for your help     E mail dmarker5@hotmail.com

Topic by 123COOPER    |  last reply


Wiring relay with limit switch to limit revolution of 12vdc motor to single revolution using a momentary toggle switch? Answered

I am attempting to wire (with my limited electronics knowledge) a 12vdc motor under a hopper to limit the revolution of the motor to single revolution each time the momentary toggle switch is activated.  The motor is connected to a cam that has a hole partially through it that, when the switch is toggled, should fill with product from the hopper, rotate taking the product with it and allowing the product to drop out of the bottom side.  This is designed to dispense a metered dose of product from the hopper each time the momentary switch is toggled.  I have a spst limit switch in place that works as intended mechanically, it is not hooked up.  I also have a 12v relay and momentary toggle switch I intend to use with this project. My problem stems from my lack of electronics knowledge, I have no idea how this relay, limit switch and toggle switch should be wired together and to the motor and power source.  Any guidance would be GREATLY appreciated!  --MIKE

Question by MikeM392    |  last reply


Controlling a DC motor to only do one rotation and to be triggered using limit switch.

Hi, I'm designing a mini golf hole for a festival in 3 weeks. The idea is to putt the ball in one hole and another ball to be released on another hole. I'm going to use a limit switch to as the trigger signal, but not sure how to get only one rotation on a dc motor and then to reset the trigger. I have to run the whole circuit off 12v battery's. Any and all help would be greatly appreciated. Thanks!

Topic by cmc graphics    |  last reply


Need Help With Wiring Up Two Limit Switches?

I have a closure system with deadbolts that works on a sliding assembly with a solenoid that turns 180-deg to close and the other 180-deg to open. It is accomplished with two limit switches (as shown in the picture attached). My question is I have a single control button. If I press it once -- I need it to trigger the power in conjunction with one of the limit switches (to stop the solenoid at the appropriate time) and then on the next press of the button, send power through the other limit switch so it cuts power at the appropriate time. Obviously if I wire everything at once you have one switch open when the other closes and vice versa so power continues. My question is this. I believe I can use a 4017 chip to allow power to go to one and then the next with each press of the button. However it seems like overkill and I figure that there has to be a simple one-two power diverter switch of some kind that I can put between the button and the solenoid/limit switches so it cycles between the two. In other words. When power comes through it the first time, it routes it into limit switch #1, the next power cycle goes through to limit switch #2, and back and forth. Is there something simple like that. If so please share. If not, can someone please tell me the best way to wire up a 4017 chip for this purpose. As always, thanks in advance for any experience, advice and/or wisdom -- it is greatly appreciated.

Question by pletchman    |  last reply


Limit current to 170v 5 amps?

So... I connected 120v ac mains power to a bridge rectifier > capacitors to smoothe > switch > output... how can I prevent the breaker from...breaking.  Also the integrated bridge rectifier can only take 6 amps for long amounts of time.  I need to somehow limit current without limiting voltage (at least to much)

Question by TypeNameHere    |  last reply


Electronics Question: Double Switch

I figure that this is a simple question, but I have a pretty limited knowledge of electronics. Would it be possible to hook two switches up (in parallel) to an LED, so that if either switch was toggled, the light would go on? I'm almost definitely sure it would, but just wanted to make sure. Thanks!

Topic by Bran    |  last reply


IR Switch. Will this work? Answered

Hi Guys & Girls Obviously, i am new to this and my electronics knowledge is very limited. Let me first explain what my desired outcome is and then proceed with the questions i have. In the schematic below i connected two circuits that i found. One is a infrared receiver and the other a flip flop. With that, the following needs to happen : when the user presses a button on a IR transmitter aimed at the receiver circuit in the schematic it is sent through pin 3 to the flip flop circuit which in turn puts the relay in a (permanent) ON state. When the user presses the same button again, the process is repeated and puts the relay in a (permanent) OFF state. So bottom line a 1 button/channel IR press on press off switch to switch my 12v circuit on/off. Here are my questions: 1. Is the receiver circuit correct as i have drawn it i.e. will it work? 2. Is the flip flop circuit correct as i have drawn it i.e. will it work? 3. Where i have the red circle : 1. Is the connection between the receiver and flip flop circuit there correct? 2. Do i need another resistor there? 4. Do i need a “floating resistor” as a R5 around the relay and how does the practical application of this look (on all the diagrams i look at it’s drawn around the relay going from an input to an output on the same wire......does that mean that on the pcb it will run parallel between the “pos+ and neg-“ going into the relay?) 5. Is my relay connection correct within the blue circle? 6. All and all, put together will my circuit work as expected? I know there are probably a whole bunch of ways to achieve the result i am looking for and being a noob, this might be the most impractical(i don’t know), but the reason i went this route is because i have these components available to me and if at all possible, i would not want to go and buy other components. Thanks in advance for any help provided. I find it much easier to learn by building the circuits and then seeing with a multi meter etc. what the effects of each component is than reading through all these books and trying to cram everything into this thick skull of mine  Schematic Component Values : R1 = 220k ; R2 = 100k ; R3 = 10k ; R4 = 10k ; R5 = ? C1 = 1uf ; C2 = 0.01uf ; C3 = 10u Rx1 = Any tsop/similar U1 & U2 = 555 timers

Question by GhengisKhan1981    |  last reply


I'm having trouble with my sketch regarding how to code , my stepper motor traveling to a limit switch then reversing and accelerating to another limit switch.

I'm having trouble coding at a point, I built an Equatorial Platform for my telescope so I can track the stars.I have a Nema 23 stepper( 1.8 * step, 200 steps per rev.) motor with an Arduino and a Easy Driver for my micro controller. My problem when I make my sketch I have the stepper motor running at 92- 104 RPM with a potentiometer to fine adjust, at this point when my platform hits a limit switch then I want to reverse the motor and accelerate it to 2000 RPM then decelerate to 25 RPM before the platform hits an other limit switch, then start the process over.How do I incorporate accelerating coding that to a certain point then decelerate motor before it hits the other limit switch. Do I need to find some timing coding ( for some length of time), before I want the motor to decelerate to hit the second switch. I don't want the motor running at 2000PM to hit the limit switch, I want it to decelerate before the limit switch. then reverse the motor again to 92 - 104 RPM. I'm a novice at coding with little electrical background. Your assistance is greatly appreciated. Jack Brockhurst e-mail jacam9803@yahoo.com

Topic by jacam9803    |  last reply


How to limit welder current (heat)? Answered

Hi All, I admit to being electrically dumb, well one step above dumb, I'm a software engineer not electrical engineer, but I don't even know enough enough to be dangerous yet:) I'm going to be converting an ac welder to dc. It's a harbor freight 90 amp flux wire job, comes from the factory as AC for some unknown reason, but should be DCEN for FCAW welding. There are several walk throughs availabile online. I don't know the rules for linking to other forums, so I won't post a link, but you can google 90 amp welder dcen conversion if you want details. I attached an image of the circuit I got from a post by bluecatfish onweldingweb. I'll be taking the transformer output, running through a full bridge rectifier to convert to rippled DC, using capacitors to remove ripple, and lastly running through a torroid inductor. Another problem with this welder is it only comes with high/low power settings. The low is still too hot and burns through thinner metals.  I want a way limit current further, but maintain voltage for a stable arc. I'll be adding a bleeder resistor to drain the caps, which gave me an idea. At first I thought to use several more resistors in parallel with the bleeder to reduce current. I imagine this might work but be horribly inefficient. It would still use all available power from the supply, just converting some of it to heat, leaving less power for the arc. I've read that adding resistance in series will reduce current, but won't that drop voltage available for the arc? Then I was thinking, I have a motor speed control for a router. I believe this is a pwm. Could it be used to chop the mains input (120v 20a) to the transformer and reduce overall output without effecting voltage(I've read this is 38v 80a in the factory state before my mods)? since I'm adding capacitors downstream, will they just discharge too fast leaving me with ripple/pulsing? If so, how would I slow the discharge rate? (I'm looking at 3x or 4x caps 22,000uF @65v in parallel on a bus bar, so 66,000 or 88,000uF total). Sorry if in not making sense, as I said in the intro, I have a lot to learn, and right now, the more I read, the more confused I get. Edit:  After more research, and to hopefully use correct terminology, I think I'm talking about using a current divider when referring to multiple resistors in parallel to the welding leads. I think I'm referring to a switching regulator when I suggested using a pwm to chop the transformer input. Can either of these work like I'm hoping? Is there a better way, that is relatively simple?  Thanks in advance for your patience and help. 

Question by DonaldF9    |  last reply


how to reverse the polarity of a DC motor using a DPDT relay, limit switch, and timer?

Ok, i am not an electrician and understand very little, but here's what i want to do.  I have a reversable 18V cordless drill I have taken apart to get at just the motor.  What I want it to do is turn on automaticallly with a timer in one direction and shut off (with a limit switch?) after about 2 seconds.  About 14 hours later I need the opposite action. Both actions automatic using a timer with AC power.  The application is a door opening and closing veritcally (chicken coop door).

Question by StevesBees    |  last reply


How to wire a 12v motor and limit switches to raise and lower a satnav panel in my car,using the ignition switch circuit

Hi, I'm trying to understand in a simplified diagram how to use a 12v motor to raise and lower a panel in my car,the hardware I can make fairly easily but it's the wiring I'm struggling with,I understand that 2 limit switches have to be used to stop and start the motor,also that the polarity of the motor has to be changed to raise and lower the panel, I also want to use the vehicles ignition switched circuit to raise and lower the panel as opposed to using a rocker switch, Any help in this matter would be greatly appreciated, Kind regards, Darren.

Question by Rallyingace    |  last reply


Best way to switch multiple circuits?

Hi, all - first time posting. I have limited knowledge with electronics and have come across a scenario where I basically need a kill-switch for a cable with 9 ends. I can't find any sort of toggle switch (SPST, DPDT, etc..) that would accommodate that many wires. I started reading up on digital bus switch IC's. It seems a 10-digit one like this would work, leaving one unused. http://www.digikey.com/product-detail/en/74CBTLV3861PW,118/568-8418-1-ND/2765135 My question: is this the easiest solution? I simply don't know what all options exist, so any advice from someone more experienced would be greatly appreciated. Thank you for your time. -Caleb

Topic by calebpaul    |  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


switch to control dc when ac is turned on?

Hi i've got a arduino project on the go and when my arduino switches on a relay to operate a 240v ac motor, i also want it to turn on 24vdc motor. I know i could just use another relay but i'm not wanting to power the relays separately, just want to power the aurduino, and yes the board might be able to power two relays but it's pushing the limits i think.  I'm not to sure if this is called a reed switch or even if there is something like what i am after available?  

Topic by JonathanM221    |  last reply


Need help to make the stepper motor rotate in forward and reverse direction using limit switch?

This is the code I used to forward the stepper for 360 degree,reverse the motor for 360 degree without using the switch. I need help to make the motor rotate in forward direction for 180 degree only after we click a limit switch and when we click the switch again,the motor have to rotate in reverse direction. int pinStep = 3; // the number of the step pin int pinDir = 2; //the number of direction pin int oneRevStep = 1600;//one rev is 1600 steps int speed = 2;//for 2 milliseconds delay void setup(){   pinMode(pinStep,OUTPUT);   pinMode(pinDir,OUTPUT);   Serial.begin(9600); } void loop(){   move_forward(oneRevStep,speed);   delay(1000);   move_backward(oneRevStep,speed);   delay(1000); } void move_forward(int step,int speed) {   int i;   digitalWrite(pinDir,LOW);   for(i=0;i   {     digitalWrite(pinStep,HIGH);     delay(speed);     digitalWrite(pinStep,LOW);     delay(speed);   }     digitalWrite(pinDir,LOW);     digitalWrite(pinStep,LOW); }   void move_backward(int step,int speed)   {     int i;     digitalWrite(pinDir,HIGH);     for (i=0;i     {       digitalWrite(pinStep,HIGH);       delay(speed);       digitalWrite(pinStep,LOW);       delay(speed);     }     digitalWrite(pinDir,LOW);     digitalWrite(pinStep,LOW);   }

Question by MELVINJ5    |  last reply


Two DPDT switches with timing for one motor Answered

Hi, I have a motor (12V DC) that I need to be able to operate both backwards and forwards from two locations. The simple way is to connect it with two DPDT switches with momentary on in each end and off in the middle, i.e. also called (on)-off-(on). The reason for using momentary switches is that there would otherwise be a risk of short circuiting if one of the switches are left in on-position. However, I almost always need the motor to go to preset limits in both directions which takes a couple of minutes (the limits are built-in functions in the motor, so no need to set those). So I was wondering if there was a cheap and easy way of inserting a kind of timer or similar that would only leave the connection on for a couple of minutes only (and yes, there would still be a risk of short circuiting within those two minutes, but it would be unlikely to happen)? Or perhaps there is an even simpler way of doing it? Any ideas would be welcome. In (the likely) case the above is not clear, perhaps this will help: I need it to operate a curtain, i.e. moving the curtain up and down, but I need to be able to do that from two different locations. Preferably it would be good if I could also stop the engine somewhere in the middle - as I would be able to do with a switch simply be releasing it. The best/cheapest/easiest way would, I think, be to have two DPDT switches with a spring or something with a couple of minutes delay, i.e. if it is left in the on-position for more than two minutes it would automatically spring back. But such a thing seems not to exist... or? Would be grateful for any inputs. Erik

Question by eriktoft    |  last reply


Arduino + Timing Device used in Profession Rugby

Hi, Patrick here. I am building a scrum sled training device and hope to use an Arduino MEGA to do the thinking! Basically the idea is simple enough. I want the Processor to start a timing sequence once a start button is pushed. I want the processor to then activate a voice saying, 'Touch, Pause....Engage' Much like you hear the ref saying in professtional rugby. Once the word 'engage is said by the processor through a speaker or buzzer, a timing sequence would start, and ending when the player makes contact with the pads on the scrum sled. This conact will bge made by limit switches feediong back into the processor ending the sequence. I have attached a PDF of the sled design. Can Anyone help me with the programming!? ANY HELP at all, is very much appreciated. Thanks again, Patrick

Topic by Pabyrnes24    |  last reply


Peltier-element: Limiting its heat by tapping the power?

Hi I have a question based upon logics and the function of a peltier-element. we all know, that you can supply power to a peltier-element to raise the temperature on it one side and lowering it on the other. So it increases the differential. Now: If we heat the "cool" side and try to radiate the heat off the hot side (eg cooling it a bit), we can get a small amount of energy off the peltier as electrical current. The current depends on the temperature-differential: The bigger the more. OK so far. Nothing new. But what made me think was the fact, that you have 2 opposite states: Heat Side C and cool side H --> Get energy out in proportion of heat-differential. Put energy in --> Side C gets cooler and side H gets hotter in proportion of energy supplyed. By getting energy OFF the peltier, you in some way, redirect some parts of the heating-energy to the electrical-output. Also that is nothing new and we all know that since energy cannot be generated but only converted (in our case from thermal energy to electrical energy). Now what puzzles me is: Does it actually affect the temperature (-differential) of the peltier, if you get energy off it? Lets imagine the following experiment: - You build something like in https://www.instructables.com/id/Candle-Powered-Electric-Candle/ - Now you disconnect the load (lamp) and measure the temperature on the upper side (Away from the candle). - Wait for a steady-state when the upper side doesn't get hotter - Now turn on the lamp thus redirecting a bit of energy away from the peltier. - measure the temperature again on the upper side. Does it lower the upper temperature a bit? of course it wont be lower than the unheated state. But lets say the steady state was 55°C. Would it be like 50°C if i switch on the lamp?

Topic by Orngrimm    |  last reply


I want to make an on of circuit but want a time limit on the power when the circuit is switched on. 6V DC? ?

I am using 4 x 1.5volt AA batteries for power and i want it to activate a magnetic solenoid once it is switch on but want the power to either to turn off or drop in voltage so the solenoid will release once deactivated...

Question by JoeCare    |  last reply


the motor driver L293D controlling the direction of motor, i want to use limit switch to control two position of motor

I am developing a automatic gate project. I want the DC motor stopped as soon as the gate closed or opened completely. I use IC L293D to control the motor forward or backward. This project is also using Arduino. I plan to use a limit switch to control the movement of  DC motor.

Question by FarhanJ    |  last reply


Need help with the wiring diagram

I have 2 Limit switches, 1 6v DPDT relay, and a motor.  By using a timer, I would like to reverse the direction of the motor when it reaches the respective limit switches.  Can someone help me with my connections.  I numbered all the terminals so you can just tell me 3-5, 6-2, etc.  Thank you so much in advance. 

Question by uamusa    |  last reply


how do i rotate a 3 v dc motor 90 degrees at a time?

I would like to use a limit switch to stop the motor and a push button switch to start it again and move it to the next stop. There will be a mechanical arm at each 90 degree position to trigger the limit switch.

Question by reland    |  last reply


Trying to make a turret with stepper motors, limit switches, and a joystick. I would like some help if possible

Making a turret that runs on four stepper motors to turn it 360 degrees. than one stepper to tilt the gun up and down, which has 2 limit switches and has a door lock actuator to fire the gun. all of this ruins on a 4 position joys-tic with a button to fire. trying to have this run on an Arduino Uno if possible. would need help coding and figuring out the wiring

Topic by Sweetcorn_18  


ATTENTION ENGINEERS: Inductor to limit inrush when starting an electric motor?

The situation: I am using a contactor (like a big switch) to start a brushed permanent magnet DC motor. I am not using a motor controller. The motor is a Mars 0909 which draws 4.8 KW continuous and 15KW for 30 seconds The problem: This current can cause arcing at the contactor which can erode the contactor's electrical contact points and perhaps stress the batteries or blow a fuse needlessly. The goal: Reduce inrush while the motor starts up. The question: My teacher suggested I use a large inductor in series with the contactor. Theoretically the inductor would resist the initial inrush of current and then its resistance would go way down. We looked around a bit and didn't find any motors in series with an inductor in series. Is there a reason why inductors an not typically in series with motors? Is this something like a "Peterson coil" or an "arc suppression coil"? Any idea what the formula would be to calculate the size of such a coil?

Question by snotty    |  last reply


How can I use a button to control a loop within a specific time limit?

Hello everyone,in my code below I have a button that initiates several actions. Initially it is set to LOW and when the button is HIGH several actions occur. I would like to add a time limit of 3 seconds so if the button stays LOW after that a different set of actions will occur. I tried using the if/else functions. Any suggestions will be appreciated!Thanks!Thomas. #include Servo s2; int BUTTON = 2; int COUNT = 1; int buzzerPin = 8; int counter;void setup() { Serial.begin(9600); pinMode(10, INPUT); pinMode(13, OUTPUT); pinMode(12, OUTPUT); s2.attach(5); } void loop() { unsigned long start_time; unsigned long stop_time; s2.write(6); if (Serial.available() > 0) { char data = Serial.read(); // reading the data received from the bluetooth module switch (data) { { case '1': start_time = millis(); Serial.println(" "); Serial.println(" Go...Go.. "); for (counter = 0; counter < 3; ++counter) { switch (COUNT); int servo = random(5); while (digitalRead(BUTTON) == LOW) { digitalWrite(13, HIGH); digitalWrite(12, LOW); s2.write(90); delay(10); } if (digitalRead(BUTTON) == HIGH) { Serial.write ("*S"); tone(buzzerPin, 600); delay(50); noTone(buzzerPin); digitalWrite(13, LOW); digitalWrite(12, HIGH); s2.write(6); delay(600); COUNT ++; Serial.print("You hit "); Serial.println(COUNT); } } } Serial.println(" "); Serial.println(" Finished: "); Serial.println("Your result is: "); Serial.print(COUNT); Serial.print(" Target in "); stop_time = millis(); Serial.print(stop_time - start_time); Serial.println(" Time"); Serial.println(" "); if (COUNT > 0) { COUNT = 0; } } } }

Question by tomstell1111    |  last reply


Possible to use a single foot pedal switch to activate a linear actuator?

I acquired this mechanism which I would like to modify for ease of use. The original set up uses a linear actuator and a 3 way toggle switch. The linear actuator comes with built in limit switches. The 3-way toggle is not practical as my hands are fully utilised on the work bench. I would like to modify the set-up so that I can use a single foot pedal switch to get this motion. One step on the foot switch and the linear actuator extends to its maximum length. Then another step on the same foot switch and the linear actuator retracts to its maximum. Any help with the circuitry and parts will be greatly appreciated. Thanks in advance. ROY

Question by anslemroy    |  last reply


How to get a linear actuator to open &amp; close a door &amp; switch a relay at the end of the stroke so it reverses direction Answered

 It would be simple with a manual relay switch but  I don't want to have to be there to throw the switch. I want a timer to do it each morn and eve so the door opens at one time then next time timer comes on it closes. The Linear actuator has limit switches to stop the motion at the end of the stroke. I need the next time it powers up to reverse motor direction.  Also will need to get power from 110v timer switch to 12v power supply to the LA    Also if it is powered from the timer I use now to power the lights, they will stay on for 2 hours then off. So the relay must not send power back right away but delay until the power goes off and the next time it powers up then send it to the LA. Or I need a separate battery power source and timer that will just give power long enough for one stoke then off. Not sure how to do that. Any electrical wiz kids out there can help me with this?

Question by Wellthmaker    |  last reply


Power supplies struggling, should I be limiting the amps going to these DC actuators?

This project started as this instructables project  https://www.instructables.com/id/Arduino-Controlled-Robotic-Drum However, instead I'm using a relay board (sainsmart 8 channel) and arduino to switch power from 4 separate wall plug DC power supplies to the individual actuators. Each power supply is connected to 2 channels on the relay, powering 1 actuator each. These are the car door lock actuators Working voltage: DC12V Current consumption: 0.15A-2.22A I am using 1 x 12v, 4.5A power supply, and 3 x 9v 1.5A power supplies (since this is what was needed for the original instructables project) However, I'm noticing that the actuators will sometimes not fire when the circuit is connected, and they seem to be limited as to how quickly they can fire. This is more of a problem with the 9v than the 12v power. The 12v, when supplying power to two actuators at the same time, will not work. I don't understand how the instructables project seemed to have no issue powering these actuators with three 9v 1.5 supplies powering 12 of these actuators (with shields that can only output max 1.2A per actuator). So that got me thinking that the motor shield is doing some sort of power regulating for the actuators. I think a single actuator, unregulated, is gobbling up all the power to the point that the power supply is shutting off, or at least has no more power to supply to anything else. Q: - Do I need to build some sort of regulator for each motor to limit it's power consumption? If so, what kind of regulator? - Should I just increase power supplies to higher Amps until it's not a problem? Any help is very much appreciated.

Question by Trrl    |  last reply


How to limit A/C current draw from gird and draw power from secondary grid tied solar inverter ?

Micro grid tie inverters are an excellent power source and can be linked together to generate energy, however they do not function when grid is down, this is for the safety of line workers. In a real world scenario I want to ensure that all power is drawn from the energy produced by the micro solar inverters as the primary source while it can produce power and not from the grid which will act as a secondary power source, this will require some sort of current limiting solution from the grid without reducing the voltage to keep the inverter working.   For the safety of line workers I would like to have an automatic transfer switch which will have both the primary power source from grid and a tertiary inverter backed battery backup so that when the grid is off, the power is drawn from the Inverter and there is no power fed back into the line keeping lineworkers safe and since pure sine wave produced by the inverter can activate the grid-tie inverters and it should theoretically increase the VA of the UPS to the size of the installed Grid-tie micro inverter capacity, the automatic transfer switch should take care of switching between grid when power is on and to the backup inverter when power is off.  TIA for any advice in this regard !

Topic by Ruben GeradM    |  last reply


is this legal??? (knives) Answered

i know of switch blades(in ohio) that they must be under 3 inches (is this correct?) but i was wondering about manual knives what is there limits? also is thid knive considered a switch blade and it does have a blade over 3 inches http://www.swordsofmight.com/schradenitromagicknife.aspx

Question by knexsuperbuilderfreak    |  last reply


The dirty little secrets about switching to LED lights

Some years ago we were told to invest in more energy efficient lights for our homes.Incandescent was using too much power, so CFL's, Compact Flouroscent Lights were the ting to buy.Much higher price than the normal lightbulb but hey we save a lot of money in the long run.No one liked the long warm up time to get full brightness...And even less people actually got the claimed lifespan out of them.Add the recycling costs and hazardous waste created and the costs of using CFL's is actually much higher than standard light bulbs.The only savings were for the power companies.LED lights had a slow start but once mass production started price went downhill fast.What started in the EU was made compulsory in other countries soon after: A ban on incandescent light bulbs.Thee are only a few exceptions left like bulbs for your oven as LED's won't cope with the temps here.So why was the ban necessary?An incandescent light bulb was available for often under a buck, so having some spares at home was no issue at all.Making people switch to LED lights that often cost 20 times the amount of an old standard light is impossible.Biggest incentive of course was the short boom to the local economy as the initial batches were all sold as high quality items.The scam started to evolve when it became clear that even with LED lights the overall savings hugely depends on how you use your lights.As a factor on your electricity bill the lights are usually at the bottom of the list.Things like heaters, airconditioners, fridges, freezers and of course TV's are the main users of electricity in many houses.During the winter times this changes as we need more light but still the impact is not as high as you might think.What did change though was the behaviour.Since we now save so much energy we don't really worry as much if the light is kept on for no good reasons.Again, the main savings are with the electricity providers.I won't deny though that a house with 100 60W incandescent lighs will have some benfit on the electricity when switching to 8 or 10W LED lights....Lifespan...Like so many others I have some stories about incandescent lights...For example the one had in the basement when I was a kid.Often on for several hours, sometimes just for a few seconds to quickly grab something.But it still worked fine when I was an adut and never had to be replaced.Or the house that destroyed lights on a regular base thanks to power surges from the nearby industrial areas.LED light were meant to make the difference here.Put them in and never worry about replacing.10.000 or more hours before the LED's fail...Nice claims but never fully true.10.000 is a bit over a year of constant use.Most people won't just leave the lights on for the entire year.So you would expect that a good LED light will work just fine for at least 5 years, under normal conditions close to 10 maybe.There is several problems with this claim - none of them are explained in the warranty leaflet and nothing was explained by your government when you were forced onto LED light.Electronics even as simple as a resistor come with a limited warranty.Some will remember the disaster when bad capacitors turned thausands of flat screen TV's into flashing lightbulbs.The parts used to make the lights can be a year old already before they are soldered together.Then there is time for shipping, storage, distribution.Sadly not all countries require to print the manufacturing date on the packing or LED light.Means that by the time you put a new LED light bulb into use it might be two years old already.Similar for the claim that the light won't emit heat.Sure the LED light itself is cold but the heatsink the LED's are mounted on is far from it, same for the often underrated electronics inside.In return the electronics suffer from the excessive heat, espcially if mounted in lamps not designed for them.Which makes the entire replacement a scam for most people.It is not uncommon that a LED light fails within a few months.If you are lucky to have kept the invoice for it you might be able to get a new one from your store.Now I replaced 20 lights when I moved in here.Only the first three that failed got replaced, after that the shop claimed I would misuse the warranty.I inspected them and it was not easy to get inside.The switching IC used should have had a heatsink according to the datasheet, without it the circuit board got toasted until the IC finally cracked.Without a sufficient heatsink the IC was only rated for a max of 5W while the light had a LED assembly of 15W...I kept doing these destructive examinations whenever a LED light fails.So far they ALL had sure signs of overheating, either for the switching IC or the tiny transformer.No one really bothers though to keep track of the hours a light was actually used and with that we just keep buying new ones with no worries in the world.Recycling....An incandescent light was never really worth much to begin with, so the final grave was the normal rubbish bin.CFL's required proper disposal due to the hazardous materials in the tubes.A comparison between the amount of sold lights and what ended up in recycling centers reveiled that the ,ajority of them ended in landfill because people tossed them in the normal rubbish.The long term impact of those chemicals on the enviroment will be hidden under fresh grass by then.LED's claimed to be the way out as they were meant to be fully recycleable.What really happend with our collected recycling bins was clear when China stopped taking it.....Means all the still usefull materials in those expensice lights again just go into landfill.A total waste on so many levels.So what is the real cost then?Electricity prices are only going up, so saving Watts wherever possible is a good thing.But ask yourself:How much energy and ressources were required to produce an incandescent light bulb?How much more is required to produce a LED light?We are told to focus on our electricity bill alone without considering the overall costs.Since we already pay the extra of making them we tend to forget what happens once they fail.More waste, more landfill, no recycling of the lights at all.But does it prevent your next blackout when the grid is at max capacity? Nope...Keeping your big airconditioner off for a hot day or two would save more electricity for the year than changing from incandescent lights to LED's ;) Does that mean we get way more efficient airconditioners? Nope...Where in developing countries cheap and highly efficient compressors are used we invented inverter technology ROFLMakes no difference at all on max power to have an inverter.The only real difference is that it runs slower at lower capacity while a normal airconditioner turns the compressor on and off.Forcing the use of highly efficient compressor technologies and replacing our old style systems would have made a real difference on the overall electricity use.We "save" electricity with LED lights and only turn them on if we really need them.Still the 5 or 7kW airconditioner runs all summer long and in the winter it heats the house and uses even more electricity.Makes you wonder, doesn't it? ;)

Topic by Downunder35m    |  last reply


How can I control the up/down movements of an electric hoist?

I have a hoist that is a northerntool.com/shop/tools/product_200660033_200660033. I would like to control the hoist's toggle switch circuit which has a LMG CBB60 capacitor (25uF+ or - 5%, 250V AC C40/70/21 50/60HZ). The hoist is 110V, 125 watt output, 1.5 Amps, 1.7 HP with a lifting speed of 16.4 ft/minute. The duty cycle is 10 minutes at 20%. The weight to be lifted is less than 50 pounds. The hoist also has a limit switch.  I would like to be able to specify 15 up/down movements of the hoist that can be repeated. My question is how can I do this? Any comments are greatly appreciated. Please see the attached images of the limit switch and the toggle switch. The toggle switch includes a large capacitor which is just shown on the right side of the photograph.

Topic by gersthei    |  last reply


i am looking for a switch with microprocessor to operate a servo motor. to use in a puppet or costume character head ?

The servo would be used to move eyes, eyelids and possibly the mouth. Basically I want to operate a servo without using a radio control unit Space and weight are limited. I am a pro puppetmaker and know this kind of device would be very useful. The motors would be operated by a switch in the puppets mouth. In the case of a costume character I want to put a push switch in the perfromers hand and have them operate the mouth.

Question    |  last reply


random led scrambler

I recently was asked a challenging question concerning a type of circuit design. My electronics knowledge is somewhat limited and was wondering if i could get some help on this project. The project is: How do you get one led to light up amongst a row of say ten or more leds by selecting from one switch from a row with the same number of switches. The system should be set up so every switch will have a randomly selected led circuit. In other words the leds are randomly scrambled for the switches. This is basically a type of led guessing game but also involves guessing witch switch will operate which led. Thanks!

Topic by eddicur    |  last reply


How to wire 2 wire actuator with 2 wire Dc adapters as 3 way switches Answered

Trying to figure out the wiring to operate 1 actuator using 2 on/on switches. Anyone care to help out? Actuator has built in limit switches. 24" stroke. It will open all the way and door will be closed and then open all the way when the switch is triggered on either end. Same as a hallway light that operates from 2 location in the house. The tricky part I've found is getting relays and switches to reverse polarity. I know how to wire a dpdt switch to move forward and backward on the actuator. But with another switch to do this I've been told I need relays. I don't understand the circuitry and tech talk, so please bare with me. Pictures say a lot, so if you can add photos or links that helps most.

Question by nowrydell    |  last reply


can i switch a boost mobile sim card into an unlocked blackberry tour 9630 phone or will there be complications?

I have an unlimited boost mobile phone, I like the flat rate fee and service but would enjoy a better phone like a blackberry. I have heard several different answers about whether i can exchange the sim card and use the blackberry with my boost mobile account. If anyone could answer with explanation of complications or limitations.

Question    |  last reply


How can we know about the position of DC motor!stepper motor is avoided in this case!?

I need to know the exact position of the motor! what kind of feedback techniques can be used in this case? and any limit switch possibility is there? like the motor crossed certain position and then the switch on that position is turned on/off! just wild guess

Question by Nr-Think different    |  last reply


Old CD/DVD Drives with 2 wire DC Motors for DIY CNC

With a lot of old electronics lying around, I embarked on taking them apart  with the intention to use the sled motors to build my first CNC. Unfortunately, I found only 2 wire DC Motors with limit switches on the laser sleds.  Here is a list: 1.Sansui DVD with Sony Laser Carriage- 2 wire sled motor with Limit switch 2.DVD player from 32cm Bahun TV        -2 wire motor with limit switch 3.CD Drive from Dell Laptop                    -Miniature motor with LS & 2 track ribbon connectors. 4.Mitsumi 31/2" Diskette drive                 -Stepper with less travel The only 4 wire stepper motor was on the diskette drive. Is it possible to use the 2 wire DC motors in my project? What sort of logic control will be required. How did they function in the DC/DVD drives?

Topic by Dolon12  


Disabling daytime running lights on '99 Sienna?

Tried pulling the fuse (works but also cuts HLs), don't want to short E-brake limit switch (although that will cheat the circuit). I'm thinking of cutting the "DRL resistor", will that work?

Topic by Razortape    |  last reply


12V DC Diagram that shows a motor reversing on its own?

So I made this moving remote control target system. I used a treadmill Motor to connected to RC car speed controller with a radio receiver. Works good but now I want to up grade I'm new to electronics and have a basic idea. What I want to do is have the motor hooked up to a speed controller and  run till a certain point then reverse. the opposite direction. I know limit switches are incorporated some wear any one have an idea how the diagram would look thanks

Question by unshiftedmatt    |  last reply


How do I wire a 12V DC motor to micro switches, relay digital timer and battery?

I am wanting to wire up a door to my hen house that will open in the AM and close in the PM. I have a 12V DC powered cordless drill motor and a digital timer. Can you help me on what I need to make this all work as far as switches, relay, etc. and possibly give me some guidance on how to wire it up? Just so you know, I have very limited electrical experience. Thank you. Rod

Question by dobecool    |  last reply