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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Recommendation for proper relay to trigger wired doorbell with wireless intercom

I was just searching my question and found someone on here recently asked this question: I am looking to do exactly the OPPOSITE of this. I would like to use the pushbutton of a wireless ...
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1answer
15 views

Replacing a relay with transistors in this step down circuit

I've made a simple circuit to step down voltage from 12V+ to around 5V, and while it works, it is noisy and it requires much capacitance. I would prefer to make it using transistors instead of relays. ...
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32 views

ic relay.. is there any delay for the responz of <İC insıde the circuit

Regarding SPDT ic relay TS5A3157. Do we have a delay responz inside the İc/ do we have a click sound. Because im startıng for a new project that can switch wireless, bluetooth or ir. What i need on my ...
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26 views

What kind of relay do I need for for 12V source with a 5V control voltage

Trying to figure out which relay I need for a project I'm working on. The source is a 12V battery, and I'm looking to turn on a 12v solenoid using a relay. I want the control voltage on the rely to be ...
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1answer
32 views

What is the name of contractors designing high power supplies with relay logic? [on hold]

I have been designing a 3 phase power supply with distribution strip and redundant contactors with failure detection (I posted a question not long ago related to that, it's based on relay logic), and ...
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3answers
486 views

What is the difference between a solid state relay and a transistor?

Along with the difference between a solid state relay and a transistor, I'm also interested to know if there are transistors that act a lot like the typical relay modules you can find on ebay (where ...
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2answers
35 views

Latching switch turning back to off on power loss

I can't twist my head around the proper use of my latching switch problem. In detail, the latching (or maintained) switch should switch a 48V DC source power supply for a cisco router. The 48VDC power ...
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3answers
57 views

AVR single coil latching relay

I need to control several 5V single coil latching relays. The specific part has a coil current of ~20mA. The ATMega's datasheet claims a maximum pin current of 40mA. Is there a reason I cannot simply ...
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1answer
37 views

Meaning of AC15, DC1, AC1, and DC13 in relay durability curves

In the datasheet of the relay OMRO G7SA from the durability curve they specify the number of operations as a function of the contact current. Each curve is for a specific current and voltage. The ...
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30 views

DC motor forward reverse using 4 x NO relay circuit diagram [closed]

1 each DC motor 12 volt 4 each relay Normally open 12 Volt 2 NO push button 1 each Battery 12 V I need the circuit diagram please
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1answer
63 views

Resistor instead of flyback diode

I was looking at the data sheet of a common 12v relay and noticed it mentioned using a resistor instead of a flyback diode for circuit protection. On the last page for 12V models it reads; When ...
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2answers
403 views

LED emergency lighting - relay activated

I've designed the following schematic for my LED emergency lighting project; I'm planning on building it soon, my knowledge in electronics is short right now (I started learning electronics by ...
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1answer
26 views

Question about the operation of a zener for a rapid relay release

This is a follow up question to Zener voltage selection for relay?. The following image was taken from the previous question I'm trying to grasp exactly what is happening in this circuit. My ...
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1answer
34 views

Zener voltage selection for relay?

This question is similar to Zener Diode Selection for Relay but the focus is in how to select the voltage for optimum or near optimum release time. With the circuit below, how does one select the ...
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0answers
65 views

Transistor switch help

For starters this is the circuit I have made. I don't have the same relay board, but it is active low. My problem is it seems my PN2222a transistor seems to be leaking current when the base signal ...
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0answers
57 views

Interleave two analog signals

I am trying to interleave two similar but not identical pass-band (analog) signals (i.e., both have a center frequency of 15 MHz, and a bandwidth of 200 kHz) on a sample by sample basis. The idea is ...
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45 views

Why do some Arduino relay modules can handle up to 250 VAC but not above 30 VDC? [duplicate]

When you look for "Arduino relay module"s, you usually see one form "SONGLE" that says on it: 10A 250 VAC 10A 125 VAC 10A 30 VDC 10A 28 VDC My ...
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2answers
186 views

Make-Before-Break Relay with Very High Continuous DC Current

I need to use a relay in order to do field sweeps with my electromagnet, which is hooked up to a couple very beefy monopolor power supply. (My magnet's impedance is ~2 Ohm, and I am putting ~40 Amps ...
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2answers
124 views

Java/Arduino Controlled 120VAC Power Outlet

I'm working on a project with an end goal of controlling a power outlet with a Java program. Currently, I have the relay wired to outlets, a 3 prong 120 VAC plug, and my Arduino. Everything works as ...
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9 views

eth008 relay pulse setup on phone app

Is there a way to set up relay pulse times for the Android/iPhone "Devantech" app when using ETH008 board? I noticed that it is possible using the test program on PC, but not possible on the app OR: ...
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2answers
169 views

Where to add Flyback diode?

I have made a relay controller module which switches a automotive relay when a ULN2003A sinks current on the separate main board. The module is in an always active state, but the requirements have ...
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1answer
56 views

High-current motor on isolated circuit causing servos to move

I have a robot with several servos controlled by an arduino. Also attached is an electric airsoft gun, which draws considerable current. The gun is on an independent circuit with a separate battery ...
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1answer
50 views

Magnetic contact circuit

Which is the best circuit for using a magnetic contact for turning on a LED strip? I would like to turn on a strip led with 12V 7A battery, but: 1 - if I use only the magnetic contact it will be ...
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5answers
143 views

Why does my microcontroller's 5V out fail to activate my 5V relay?

I am using a small microcontroller with 5V output lines to try to turn a relay on and off. I bought the relay module from Amazon and unfortunately I don't know much about what is on the relay ...
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45 views

Convert a NO push button into an On/Off button

I'm building a boombox, and it needs a couple of switches for main on/off, voltmeter on/off and LED lights on/off. Since I don't have any metalworking tools I am going to buy a premade front panel, ...
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1answer
33 views

Time delay relay

I am having trouble figuring out what kind of time delayed relay I need for this circuit or if anything will work even. It is used to keep a dome light on for a few seconds in a vehicle after the ...
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1answer
60 views

Raspberry Pi B+ with relay: Lights change but relays don't click

I am using an 8 Relay module, bought from dx.com. It has no instruction manual... This board has 8 inputs (IN1,...,IN8) to control each relay, 1 VCC pin that requires 5V and 1 GND pin. I connected ...
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3answers
69 views

Using A Relay To Control A Lamp

I'm experimenting with capacitive sensors acting as switches and want to actually give my circuits some practicality. I've been researching how to use relays with microcontrollers (in my case, an ...
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0answers
27 views

Need help to pull to gound a 13vdc voltage via a 5vdc control voltage

This may be real simple but I'm not anywhere close to an EE I can ask for help., I have a +5vdc line that remains at +5vdc until I click a mouse to generate an event, Then the line goes to ground. ...
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2answers
72 views

Problem using Relays at 220V with 595

I'm having some complications when I'm trying to control 16 Relays using 2 595, these relays control loads connected to 5V, 12V and 220V. There are 8 loads at 220V using the 8 LSB from my SPI ...
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2answers
42 views

drive a relay from a 3.3v 2mA max output

I need to drive a relay, but my logic signal is limited to 3.3v with a maximum of only 2 mA. Can I use a level shifter? I have a 5V relay with a 125 ohm coil drawing approximately 40 mA. Any other ...
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38 views

Intermediary to Cut Power to USB after Certain Time without Data Communication

I have a mouse that includes rather bright lights that, irritatingly, stay on even after the computer has been shut off and the mouse is therefore not in use. While I could probably reconfigure the ...
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1answer
56 views

Solid state or Mechanical relay

I need to control a load that uses 20A at 110v. Should I use solid state or mechanical relay? Mechanical relay's contacts can lose conductivity over time due to high current and high voltage, I am ...
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2answers
51 views

Circuit board layout: wifi ceramic antenna next to a electromechanical relay

Is it okay to place a small ceramic antenna not far from a electromechanical relay? Would the magnetic field generated by the relay coil (when on) affect wifi operation? clarifying edit: not far = ~1 ...
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1answer
51 views

Using automotive relay to switch AC

I want to use this automotive relay to switch 60VAC, the current max. is 10A. But all its parameters are for DC usage. Can I use it safely to switch AC? It states its "Max. switching voltage" is ...
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64 views

CAN bus and relay problem

I have prototyped a CAN network with a PIC MCU and Raspberry Pi in it. The problem was when I tried to use a relay with a 5 V coil voltage on one of the nodes like this: The LOCK_CTRL was ...
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1answer
40 views

Is a 5.5V to 15V GPIO a suitable controller for a 120V/30A relay?

I'm trying to create a simple computer-controlled switch for some speakers that plug into my home 120V outlets. I was thinking I could cut a surge protector or extension cord open, and wire this ...
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1answer
35 views

Sizing relay for inrush current

When sizing relays do you take into account the inrush current? For example, if I have a load that draws 2.0A inrush and 0.75A afterward, do I select a relay that have to handle the higher inrush ...
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1answer
47 views

Relay driver circuit with input referenced to positive

I built a standard relay driver circuit as shown in the first schematic here: It works as expected, but I now realized my input is between the positive terminal instead of ground. How can I adjust ...
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3answers
706 views

Why drive a relay with a transistor switch?

It appears most people drive relays through a transistor rather than directly from a digital output pin on an Arduino. I had wired the output pin directly to my relay before realizing this and it ...
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1answer
95 views

How does base resistance affect a transistor?

I'm not strong with electrical engineering and I have prototyped a circuit which works; however, to my chagrin, I don't understand why. I'm using an Arduino digital out pin to power a relay. I have ...
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1answer
53 views

arduino DC motor direction change

Hey Guys i have been following this tutorial on dc motor direction control the only change i have made is using this relay Relay Link instead of one mentioned in the tutorial. How do I proceed ...
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1answer
34 views

Electric load - Switching vs Continous

My realy says "Switching up to 16A (max. 3680 W / max. 2500 W continuous)". Does this really mean I should not have it connected to loads over 11A, in a 230V system? What would be an example of ...
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2answers
79 views

Beefcake relay control kit - Sparkfun

http://dlnmh9ip6v2uc.cloudfront.net/datasheets/Components/General/RelayBoard-Large-v16.pdf I'm trying to determine the base current of the NPN transistor but keep getting numbers an order of ...
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0answers
55 views

How to design circuit for robot motor

How to design a circuit which fulfill the requirement below. I am a chemical engineering student which do no have any electrical knowledge but still need to design a circuit for my project. Motor ...
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1answer
21 views

How to turn on gauge lights from multiple sources

I have limited experience with relays, diodes, ect. so I need a little help. I'm currently building a rock crawler (off-road buggy) from ground up and I'm into the electrical and need some ...
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68 views

Mechanical Relay Protection (Controlling AC mains devices)

Trying to make a ucontroller controlled relay to switch mains AC devices. It would have a type M plug on one end(to plug in mains socket in the wall) and type M socket on other end(to plug in the AC ...
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70 views

how to redesign the circuit to drive a 230V 100W lamp for 5 minutes

I have a circuit , the circuit operates with a siren using a 9v battery the siren used is UM3561 i want to replace the alarm part of the circuit using a RELAy that can drive a 100W 230V lamp for 5 ...
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143 views

Switching power to Stepper Motor Drive using relay and arduino

1.This project involves use of stepper motor once in 5 mins to perform precise movement.I m driving the Stepper using L298N-L297 Stepper Motor Driver Board and Arduino UNO. Since the Stepper Motor ...
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49 views

Low cost solutions for reversing 130VDC 20A motor

I have a treadmill motor controlled by an MC-60 controller board. The motor is reversible and I want to control the direction using an Arduino. The catch is that it's 130VDC and 17A (the voltage ...