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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38 views

Time delayed circuit for car

I'm trying to make some kind of time delay circuit. After I turn off the relay, that lamp is lighted for another few seconds. My idea is shown in schematic below. I have 2 questions: What value i ...
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0answers
43 views

Relay vs Switching Voltage Regulator

I have a microcontroller Atmega328p and some sensors like Dht22,Lm35,switching voltage regulator and a 9V battery.When my microcontroller is on sleep the total circuit consumption is about 11mA.That i ...
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3answers
14 views

Strange behaviour of a LED bulb via SSR Relay: it's EMI?

I've just discovered a strange behaviour of a LED bulb (E27, 220v/AC) that I'm currently turning on/off via an 8-channel SSR relay. Such a relay module is powered with a switching power-supply, ...
2
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3answers
55 views

Using PLC for more over than 200 relays application?

Hi im currently building an application to control over 200 device in a building. Originally i want to use an arduino and bunch of relays to control them. After asking some questions and such in this ...
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2answers
48 views

Shield arduino for electrical interference

I have an Arduino UNO controlling two high voltage relays via a switch. It also reads out a third relay, which is controlled outside of the Arduino. My setup looks like this: With the following ...
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1answer
75 views

A problem on Relay Power loss

On our quadcopter, we're carrying a switching circuit that would allow the switching between two batteries. When using the 2 Channel Relay Module, the quadcopter is having a hard time flying with it. ...
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2answers
49 views

ULN2003 driving Relays with status indicator

How to drive the ULN2003 to show the on/off status of relays (green LED for ON and Red for off)?
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4answers
95 views

Control 5v relay through 3.3v GPIO using NPN transistor

I'm not very pratical as I just started learning electronics and I'm planning to make some experiment with Raspberry Pi. I'm trying to control a 5v relay board that, I think, is made for Arduino, as ...
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0answers
32 views

Noise suppression on relay Coil

Attached circuit is part of my design. My design use 230VAc line , and SMPS convert it to 3.3V control voltage. In test code we toggle the relay coil at every 1 sec,(relay contact was not connected ...
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1answer
47 views

A circuit similar in working to a NOTC relay? [closed]

How do I build a circuit that gives out a "high" only when given in a "high" continuously for a preset time period? The input is actually the out from a logic gate. The following details have been ...
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1answer
92 views

Switching on and off high 50V DC circuit?

I'm having a little trouble finding a way to activate my circuit. I don't have a proper circuit drawing tool available however hopefully my drawing from MS Paint will do. //////////////////////////...
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1answer
29 views

Optimal method for switching power to a DC motor spindle

I'm trying to use a 5V DC signal from a microcontroller to electronically switch power to a DC spindle (for use within a router I'm trying to build). The supply I'm using is a 48V-DC PSU (8.3A rating)....
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1answer
42 views

multi-tap transformer relay for LM317 tips

Example circuit: Since LM317 is a linear regulator it will get very hot when i try to draw around 1 amp @1.25v with a 24v input. The transformer i have at home have these taps: 24v 12v 5v Is it ...
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0answers
40 views

Automotive Headlight Circuit. DRL

I will begin by saying that I am in no way proficient in circuitry. What I am trying to accomplish is a circuit that runs LEDs when "Headlight (H/DRL)" has power and does not send power to "Headlight"...
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1answer
63 views

Help understanding this Circuit

I have a latching relay that I don't quite understand. It's pretty simple as far as operation goes. If you apply power to contact B, (A is common) the relay latches. If you switch power to contact #...
4
votes
3answers
570 views

Does a dashed line mean “when energized”?

I'm having a hard time understanding this circuit diagram: I'm interested in the following component sates, and how they affect power distribution: the breakers: the buses: the AVIO MSTR ...
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0answers
44 views

Control from Digital to analog 120v

this is my first time asking question in this forum so forgive me if this is a stupid question. I want to use arduino uno to control the power of a light and I want to have a step in my bulb light so ...
2
votes
2answers
279 views

Using unsuitable relay in transistor switching circuit?

I'm trying to make use of this relay which operates on 5 volts, in a circuit powered by +9 volts. I'm kind of new to electronics, so bare with me. The schematic can be seen on the image below: ...
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3answers
51 views

DC rating for specific AC rated relay

I am interested in buying a high amperage relay which is AC rated (https://www.panasonic-electric-works.com/cps/rde/xbcr/pew_eu_en/ds_61A04_en_dqm.pdf). In particular it is rated for 60A @ 240VAC and ...
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1answer
18 views

Ldr relay switch

I'd like to build a simple ldr circuit that turn on a relay when it's dark. I've used a voltage divider composed by a ldr in series with a 10k resistor and 10k potentiometer, which drive a 2n2222 ...
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1answer
23 views

Demux I2C with a relay system or similar

I'm working on a electronic prototype. I have got one I2C communication master and I have six slaves to talk to. But here is the problem: the components are not built to have many addresses: only two ...
1
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0answers
45 views

Malformed relay? Outputs current from NO when no signal is passed

I'm using this (SLA-05VDC-SL-C) relay. After about 40 minutes of usage (with this module) at ~10A turing the relay off via the module seems to turn it off (click is sound and the red light turns off) ...
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0answers
17 views

Echelon Smartserver rs485 relay control

I have bought Echelon's Smartserver, a lot of 4 channel relay boards and I want to connect them all together via a modbus network and for now to control the lights of the house. I have made all the ...
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2answers
62 views

Arc voltage on the relay's contacts when load is off

The contacts of the relay (not the coil of the relay) are connected in series with water boiler (2kW) and AC power socket (220V, 50Hz). Suddenly, relay stops its operation due to the electric arc ...
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2answers
56 views

Wiring up the SRD-05VDC-SL-C to an Arduino or Arduino-like microcontroller

I'm trying to wire up the SRD-05VDC-SL-C mechanical relay to a Particle Photon and/or Arduino (not the version that is on a breadboard), and am a bit confused by the datasheet. I device I am ...
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1answer
46 views

Problem driving 4 PhotoMos relays with Rasberry Pi and FET

I am using 4 PhotoMos relays to switch some signal lines and have ended up the board below to switch a bank of four relays (the datasheet for these is attached at the end). The relays are powered ...
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1answer
79 views

Can a small voltage represent a closed circuit? [closed]

I know this is somewhat of an odd question, but I'm curious about whether or not a small (or maybe matching*) voltage on a wire can represent a closed switch. ** more about this in a moment*. ...
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5answers
135 views

Appropriate relay for water heater rated for 220VAC/1500W

I've created a complete hardware platform using a Raspberry Pi as master/controller, an Arduino nano and two RF24l01 transceivers, which should control some household electrical appliances. The ...
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votes
2answers
72 views

5v vs 12v dc pcb mounted relay selection

I'm newbie and just got stuck at design decision whether to go for 5 volt dc relay or 12 volt dc relay in power circuit.Both relays equally mentions power dissipation as 170mW according to their ...
0
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1answer
48 views

Relay circuit not switching as expected

I work on the book "Make - Electronics" doing some experiments. One of these is working with a relay. The simple schematic is this one: The circuit that I build works to 95%..... The left LED is ...
0
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1answer
51 views

An SPDT switch using TRIACs

I need to design a circuit that implements an SPDT switch using Triacs and Optoisolators. Currently I am implementing this with two pairs of Optoisolated Triacs with one having inverted signal from ...
0
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1answer
97 views

Which circuit is more Stable?

The circuits in the picture are basically opto-couplers connected to a relay circuit. The input pin of the opto coupler is connected to a MCU and the output of the opto coupler is connected to the ...
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1answer
46 views

Help wiring DC motor

first post here. I'm wiring a DC motor and horn that will go into a small boat I built. I would like to get some help to see if I'm doing this correctly. -DC motor hooked to a 12v battery (Max draw ...
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1answer
95 views

“switching box” with microcontroller and relays [duplicate]

I need to build a switching box, which switch between 4 pairs of the contacts, and give one of the pairs to the output (to read one of the 4 signals). I am going to do that as follows: For each pair ...
0
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1answer
52 views

should I use relays?

I am using attiny85 to control 4 motors that work all togather at the same time. Will that hurt the attiny85 controller or is it ok. Because I think that the 4 motors will draw high power through the ...
0
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1answer
91 views

Relay Vs MOSFET or IGBT

Curious on your thoughts for an application and the pros and cons of using a relay or a MOSFET or IGBT. The application involves switching a 96V lead acid battery pack on and off for periods of 5 ...
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1answer
60 views

Problems with Switching a Solenoid Valve with a Relay

I've been trying to switch a solenoid valve using a relay controlled by a signal from a microcontroller. The circuit works fine when connected to a normal load like a light bulb, but some random ...
3
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4answers
263 views

Symbol or marking on safety relay

I found this relay inside an industrial x-ray machine. What does the rectangular box with a horizontal line through it, in the bottom left of the first picture, mean?
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2answers
33 views

Relay sequencing: Inhibit state change of one relay if the other is on

I'm trying to find a way to have one relay lock its state if the other is on. Example, 2 relays total: If relay 1 is on then relay 2 can't change state, either turn on or off. Meaning if relay 2 is ...
0
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1answer
132 views

Is this schematic good?

Here is schematic for DC motor control. Using this I can drive motor in both directions and also send short pulses to motor, to move it only a little bit in desired direction. Let me explain schematic ...
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3answers
84 views

Looking for time delay relay or relay circuit that can be reset

Need relay control that results in a closed contact (dry) that is held for 1 minute If during that one minute another signal is received (dry or not) the 1 minute countdown resets. The actual ...
0
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2answers
85 views

Energizing relay using short pulse signal

I have DPDT relay which I would like to energize using pulse signal (duration of that pulse should be adjustable) and switch. When switch is on, coil of relay is shortly energized by pulse signal and ...
2
votes
2answers
58 views

Do latching relays controlled by two different open/close pushbutton exist?

I need to control a latching relay but I don't need to change its state alternatively with one single input. I need to control its state with two separate pushbutton: "open" and "close". Does it ...
0
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3answers
145 views

Arduino 16x2 LCD weird symbols after relay-switch

I am using my arduino to automatically change water of my aquarium. The program runs fine, the pumps, heaters and valves are controlled by relays. When connected to my laptop, I can see via the serial ...
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2answers
99 views

Using a multimeter to see if ground is connected

I've been diagnosing a problem with a relay on my car. One of the pins in the socket that the relay goes into controls the ground for the throw of the relay. When the car's computer wants the relay ...
0
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0answers
45 views

Difference between instantaneous, definite time and inverse time over current protection relays

Protection coordination is very important in transmission and distribution power networks. One of the most widely used and important protection relays are over current protection relays. What is the ...
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2answers
269 views

NodeMCU v2, driving a 5v relay

I was under impression that you can drive 5V relay with no problems, but now it seems you need additional components to do that, which makes it no longer simple. The setup I think now is the following:...
0
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2answers
97 views

How to protect P-MOSFET from excessive gate voltage

I would like to build a DIY solid state relay for my car to enable some circuits (less than 1A current absorption) only when the accessories are powered up (independently from engine on or off). I ...
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2answers
92 views

Solid state relay operation without transistor

I have this solid state relay, it's specify that it can run at 5v/16mA. I just want to make my board as simple as possible, so i've been thinking to remove transistor. Is that safe for GPIO/PORT or ...
0
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2answers
50 views

Opinion on design changes for Latch circuit

So just to give some background I've designed a circuit to suit the following task. 12V DC Motor moving a carriage up and down a column 2 'End stop' magnets, active-low hall effect sensor attached ...