A relay is an electrically controlled switch. Electromechanical relays use an electromagnet to activate mechanical contacts, solid-state relays use semiconductor switches.

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18 views

Circuit to Delay Rs-232 Tx pin closure after device power up

We have two devices connected via a cable, an arm based computer on one side and a sensor on the other. This cable carries an rs232 TX, RX, and ground. In addition there is 28v provided from the ...
0
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0answers
11 views

Relay with Physical Switch like Zwave Relay Module…How?

Hows its working either from existing wall outlet Physical switch or from zwave based controller relay triggering......Plz help let me understand this because I want implement in my wifi based relay ...
-3
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1answer
49 views

Need help with connecting raspberry pi with a relay module for watering system [on hold]

I've recently bought a raspberry pi and really want to make an automatic watering system with it however I've run into trouble with connecting everything and I'm stuck. I've never done anything like ...
31
votes
5answers
4k views

Why are there so many relays used in a car, instead of transistors?

Recently I did some work on my car electric circuits. I see many relays are used in car circuits. These relays are used for simple switching, and I wonder why these circuits are based on relays and ...
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1answer
45 views

relay coil issue

i've been googling my way through a problem and now i am stuck and haven't found an answer. So here is what I am trying to do. i have 24vdc connected to the positive side of the coil on a relay and ...
0
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0answers
30 views

Relay module not working

I bought this relay module and I tried connecting it to my raspberry pi. I attached the Vcc (one next to the inputs) to the 5v rail of the pi and gnd to gnd. I attached the input pins to various gpio ...
0
votes
1answer
36 views

Relay circuit with off switch

I've been searching for a similar circuit and only found latching relays with two momentary switches for on and off. I don't know if this circuit has a specific name or not, and since I am a complete ...
2
votes
1answer
35 views

Which diode configuration do I need for this solid state relay?

I want to add snubber or supression protection diodes for a solid state relay. Here is the diagram without the diodes: And this is the SSR I'm going to use: ...
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2answers
55 views

Cut off low voltage lithium battery?

Working on a portable boombox powered by four 18650 Panasonic NCR 3400 mAh cells in series. I bought a PCB and I have a small 4s balance charger. The PCB will be secondary if anything fails and cuts ...
1
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3answers
113 views

How can I implement a solid state relay in LTSpice?

I want a specified DC input voltage or above input voltage of a solid state relay to activate it. I want 3V or above DC input to turn on the relay's output switch. Here is the simple diagram: Is ...
0
votes
1answer
28 views

Questions about a relay controlled AC fan setup

I need to switch an AC fan by a DAQ board's analog output. Here is the setup in my mind for the moment: The DAC of the data-acquisiton board can output 0 to 10V DC and can deliver max 5mA current. ...
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2answers
49 views

Help choosing a relay for pump control

I'm building my first arduino project, and I could use some help building up the relay portion. My goal is to control a water pump that's running at 110V, 3/4hp, rated at 9A, and measured to run at ...
0
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2answers
34 views

12 volt switched by 5 volt

I have an issue with 12 volt DC LEDs installed on a 5 volt DC circuit. Switching must be performed as close to instantaneous as possible. So I searched around but nothing would do what I need. I ...
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0answers
16 views

What type relay should I use?

I want to close a switch with a pulse, stay closed until I send another pulse from a different circuit. Would form-A duel coil latching relay work?
0
votes
1answer
32 views

Good choice for a flyback diode [closed]

I have a relay with following ratings: coil voltage 3V coil turn on voltage 2.1 I have looked at IN4007 but they are available in bulk quantities only. Can anyone suggest any other diode?
0
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1answer
44 views

home automation with arduino, raspberry using externally powered relay board

I have a plan to put together small home automation system. For now I was just playing with smaller parts like single type of sensors at once etc... I would like to ask for opinion & check of my ...
0
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0answers
34 views

Amp troubleshooting with clicking relais

Im having some trouble with my old Realistic amplifier. Out of nothing, my speakers started to make a repetitive (about once a second) full in and out movement of the cone, producing a deep bass ...
3
votes
4answers
503 views

Why are my reed relays releasing 10x faster than spec?

I have Magnecraft W171DIP-25 reed relays (datasheet). They are DPST relays with a built-in coil suppressor (according to datasheet). Their listed response time is 1 ms, and, following the logic of ...
-2
votes
1answer
63 views

Help choosing component values for a relay delay circuit

I want to build a circuit that controls a relay with the following specifications: the relay should turn on and stay on for ~60 seconds after the button is pushed the relay should stay on as long as ...
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2answers
66 views

Is hobby relay adequate for air conditioner automation with microprocessor

I'd like to use a Beaglebone Black(3.3v Logic) plus a 3.3V to 5V logic level shifter(74HC125) to control an opto-isloated Songle Relay that has the following specs: Rated Resistive load: 10A ...
0
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2answers
38 views

Built-in air conditioner timer switch wiring

I'm not sure if this is specific to this model only, but I was unable to find any standard wiring schematics for this type of switch. This is for a Haier HPAC9M air conditioner unit. I want to ...
0
votes
1answer
17 views

TQ2-L2-5V latching relay

I'm using a 2 coil latching relay named TQ2-L2-5V. I came to know that, 2 coil latching relays have two modes 1.SET and 2.RESET. I want know, what happens in SET and RESET modes, in my case, in SET ...
0
votes
1answer
42 views

Switching circuit or relay [closed]

I'm new here and don't know much more about electronics.I need a switch/relay that help me off DC line when AC (grid) line is available and automatically turn on when AC (grid) line is not available. ...
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1answer
62 views

Relay driver from microcontroller

I have put together the following circuit to drive some 12V pumps from a micro-controller using a ULN2003, but it has a few issues. First issue is that the relays click in immediately. I want the ...
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1answer
33 views

Can I cable this relay to my regulator?

I have to control a temperature, with a 3.5 kW under 230 V AC resistor. I have a regulator with this OUT : 4 A / 240 V AC. I found this relay to commute my circuit. My question is : can I use it ? ...
2
votes
1answer
59 views

How well do relays handle brief overcurrents?

Unlike solid-state devices, relays often (in my limited experience) do not come with maximum peak current draw, only maximum continuous current draws. In general, how well do relays take pulses of ...
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2answers
102 views

Efficient toggle switch

Is there a way to circuit a power efficient toggle switch controlled by a SINGLE button so that absolutely no current from the power source is drawn at it's OFF ...
1
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1answer
99 views

conditional switch for classic car [closed]

I am would like to add a small buzzer or led light to the dash of my old MGA which activates only when: a) the ignition is off AND b) I have forgotten to shut off the battery cut off switch. (This is ...
0
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1answer
41 views

Do reed relays have shorter opening than closing time?

I see that 'normal' relays generally have shorter opening than closing times (see for example: http://www.langirele.com/pdf/pcb-relay-T73.pdf). Do reed relays also have shorter opening than closing ...
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votes
0answers
25 views

RC snubber circuit [duplicate]

How can I calculate the Resistor and Capacitor Values for a RC snubber circuit to drive a relay coil. Nominal voltage 120VAC, Pick-up Voltage 88VAC, Drop-out Voltage 36VAC Coil resistance 11K +- ...
17
votes
2answers
2k views

Why do I need space between two relays?

When I was reading the datasheet for these relays (http://www.mouser.com/ds/2/357/105A_117SIP_107DIP_171DIP-6475.pdf), it says to put 1/2" spacing between two adjacent relays. Why is this? As the ...
1
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1answer
34 views

Combine two DPDT relays to make a 4PDT relay

I'm trying to come up with a replacement for the obsolete OMRON G6A-434P 4PDT relay for a replacement PCB I'm building. I've got a bunch of OMRON G5V DPDT relays and I'm thinking wiring two of these ...
3
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5answers
268 views

How to avoid damaging relay used for controlling motors?

I've got a circuit with two DPDT relays controlling a motor - the diagram below is borrowed from a related but different question. RLY1 turns everything on and off, RLY2 switches the direction of the ...
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2answers
48 views

lowest loss for switch

Are there any other options for an extremely low loss switching circuit with extremely low switching frequency (about 4 times per day) and voltages from 0-3V with currents <2mA. Current ideas ...
-3
votes
3answers
74 views

Pic microcontroller relay switching of 1 HP single phase motor [closed]

The situation is I am using pic microcontroller for power supply I am using 230 to 12 v stepdown transformer + 1000 uf 25 v capacitor + lm7805 + 10 uf 25 v capacitor from and these two positive and ...
-1
votes
1answer
62 views

Power on GoPro (5V) with 10-24V using transistor or relay?

I have a GoPro 4 and a board for the GoPro Port. With this board it is possible to power the GoPro externally using 5V and to switch it on. For power supply I'm using 12V to 24V (from the Car) over a ...
2
votes
3answers
324 views

What does RU (UR) label on DC power relays mean?

I'm trying to figure out what does RU or maybe UR label mean on the body of many many relays. It's labeled almost on all (I've seen so far) DC relays which make me very curious :). Any suggestions?
0
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2answers
66 views

2 NO reed switch - turn on 230V water heater

For a small home project I would like to turn on a water heater using 2 NO reed switches. Once I put a small magnet ontop of the reed switch (turn the reed switch to Close), the water heater will be ...
-5
votes
1answer
27 views

Relay Arduino Connectivity [closed]

I am using a relay to connect one of the bulb (240V) and another end to Arduino. I have wired up the bulb to a socket. Socket Wiring:Red is connected to Line, Black to Neutral. For the below Relay ...
0
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0answers
27 views

BeagleBone Black wirelessly control a Relay Board

I'm a beginner in the field of Electronics. I'm trying to make a project where Beaglebone is used to control relays to operate a lamp, based on the output from a proximity sensor. The circuit works ...
1
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1answer
30 views

Opto isolator + triac vs. solid state relay for high AMP arduino project

I building an arduino device to turn on/off a high current (~10A/120V) oven. I was planning on using a solid state relay like this. I keep seeing advice that talks about using an opto-isolator AND ...
-2
votes
1answer
23 views

direction of a dc motor with the help of 2 5 pin relays

I want to change the direction of a dc motor with the help of 2 5 pin relays without using any switch. Can anyone suggest the wiring diagram please?
0
votes
4answers
74 views

What type of relay should I be using?

So I'm currently looking to control a lightbulb for some inefficient lighting to produce heat for a mini-greenhouse I am building. I'm looking at plugging in a wall wart 12V DC adapter and wire that ...
0
votes
2answers
108 views

Toggling a high-power relay with a Microcontroller

I've got some relays connected to some 230V high-current spotlights. I would like to control 16 of these with a microcontroller. I'm thinking of creating my own PCB. I have checked the datasheet, ...
0
votes
1answer
44 views

Switching power supplies with a relay, how to account for delay between connections? [duplicate]

this is my first post on this site (but I will have more, have no doubt), so if I have posted in the wrong section or something please forgive me. Anyway, I am currently doing a battery powered pc ...
0
votes
0answers
39 views

Relay turn off delay

I need help with my project. I want to design a circuit for my car. It goes like this: Blinker on car is made with 1-filament bulb. I want to use this bulb as indicator and as DRL (made by PWM - ...
0
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2answers
58 views

How is this relay circuit Working

I have this relay circuit to cut the ignition power of a vechile. Can someone please explain how this immobiliser circuit is working.
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0answers
55 views

Audio: Camera activated external microphone

I want to build a relay circuit that turns on an external microphone (powered by an internal 9V battery) when a connected camera is turned on (a camera offering only 1V plugin power through a 3.5 mm ...
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vote
2answers
32 views

Power Transformer with two Buchholz relays

In my workplace we have a power transformer, on its conservator tank there is a device like a Buchholz relay and its named as Atmo-Seal. What is the purpose of this device?
0
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0answers
29 views

arduino relay with 3 motors

I am doing a project where I require to control 2 DC motors and probably 1 stepper motor. The DC motors only have to work in one direction whereas the stepper motor has to be reversable. (the stepper ...