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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1answer
169 views
Relay contact voltage rating
I was looking through to buy a few relays and found the nominal DC contact voltages (~30v) are much smaller than the nominal AC contact voltages (250v). What is the reason for such a large difference?
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1
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2answers
279 views
Switch hookup with relay (arduino)
Hey all i have the following 5v relay board:
Please ignore the light bulb hook up. That was an example on the website that had the same relay :)
And i am looking to hook one of the relays up to a ...
3
votes
2answers
184 views
Is it possible to switch relay above the power spec?
I am planning to use a DC drived SPST reed relay. Below I include the spec for voltage, current and power ratings.
Contact Rating: 200W
Carry Current: 5A
Switching Current: 3A
Switching Voltage: ...
2
votes
1answer
81 views
Four-Prong Relay Useage
I apologize for the basic question - I'm just getting into electronics and have come across a diagram that I don't understand (or more accurately, don't want to risk frying my Arduino with not ...
0
votes
2answers
200 views
Is a relay one way?
I'm no electrical engineer, so maybe this is a stupid question.
I want to make my own alarm system using a netduino board.
I bought a couple of motion sensors for mounting into my ceiling.
The ...
1
vote
1answer
190 views
Simple AC line state detection for digital controller input
Last year I moved into a house that has an old ('50s-'70s vintage) GE low voltage lighting control system. It uses 24VAC momentary wall switches to toggle solenoid/latch relays that feed 12 main ...
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1answer
115 views
Program which turns power on/offf
I am a software developer and just started my journey in electronics side. I had this particular idea which I want to do for my project.
Problem statement: In my college every room has fans and ...
0
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2answers
200 views
Ethernet (100 Mb/s) through relays
I'm trying to transmit Ethernet through relays. I'm using relays because I need them to switch to another signal path, and I'm specifically going to use relays and not other switching devices so that ...
0
votes
1answer
142 views
Drive relay when “key” is connected
I'm trying to design a circuit that will drive a relay (and thus turn on a bigger circuit) when the correct "key" circuit is connected.
The "key" is contained within the hashed box and functions as I ...
0
votes
2answers
140 views
5v relay to be driven from a limited supply of 20mA which requires 200mA of latching current [duplicate]
Possible Duplicate:
Pulse-powering heavy loads with a coin cell
I have to operate a latching relay at a nominal voltage of 12 V or 5 V. Right now, i have not chosen the relay so lets ...
1
vote
1answer
81 views
Time delayed optionally postponable from a second input
I need functionality similar to that provided by true-off-delay relays, just a little different. I can't come up with a circuit.
I have two inputs (A and B) that I want to control one output (C).
...
0
votes
1answer
47 views
Routing Current to Many Individual Channels [duplicate]
Possible Duplicate:
How to implement an isolated connection matrix
I need to put current on up to 30 lines; one at a time. What kind of electronics solutions are there to this kind of ...
5
votes
2answers
153 views
What is the difference between VA and W for a relay
I am trying to choose a relay to control a compressor.
The compressor alimentation is 230V (50Hz), the max intensity is 0.9A and the power needed is 130W.
Then i found two relays: the ALD112W and ...
1
vote
3answers
393 views
Parallel port controls a relay
If I want to use a parallel port to control this 8 channel relay instead of Arduino, do I need to make any modifications?
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2answers
304 views
MOSFET or bipolar to drive a solenoid valve?
I have to drive a 12V solenoid valve. In the datasheet it's written: Power: 8 W. So the current drawn by the solenoid is 0.666 A.
Usually, to drive small relay (about 10 or 20 mA) I use a bipolar ...
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votes
2answers
150 views
How to implement an isolated connection matrix
I need to implement a circuit for a researcher, which looks a little bit like this:
Description of the circuit:
There are two or more fully isolated biphasic current drivers, and N output pins. ...
-1
votes
1answer
738 views
How can I activate a circuit with a remote control
I'm new at the forum, registered today.
Well, I want to make an system which can be activated by a remote control, or even by a switch.
The meaning of it all is to TURN ON something wirelessly, ...
2
votes
2answers
1k views
Using a transistor instead of a relay to control a DC motor
I've made a simple relay circuit to switch power to a small DC motor
Here is a diagram of what I got right now:
Is it possible to replicate that with a transistor. Which one would be a good choice?
...
2
votes
1answer
148 views
From a power consumption point of view, which should I use: SSR or Relay?
I'd like to find out which to use: a SSR (Solid State Relay) using TRIAC and optocoupler or a relay.
My consideration are from the point of power consumed, my challenge here is to choose the less ...
1
vote
1answer
482 views
GPIO and relay quesiton
I have a question about the YouTube video Raspberry Pi Controls Relay. It's about controlling a SainSmart 4-Channel 5V Relay Module. Is it driven directly off the 3.3V GPIO?
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vote
5answers
268 views
Interface 5v digital pulses to keyboard contacts?
I currently have the following bit of kit: Photoplethysmographic sensor for measuring heart rate
It outputs a 5v pulse each time your heart pulses. What I need is to do is interface this pulse output ...
5
votes
2answers
1k views
Is analog SPDT IC switch same as mechanical relay?
I am working on a project which require to trigger a SPDT switch using a button to pass a small signal voltage across (~3.3V).
reference circuit image below
The requirement is:
signal must still ...
1
vote
1answer
214 views
Looking for a 24vac switch from 3v inputs
I'm really new to building electronics, so please forgive my ignorance.
I'm looking to be able to supply 24vac (~.5A) to one of 16 outputs using 4 3.3v, 50mA inputs.
(Edited) The 4 3.3v inputs are ...
10
votes
5answers
487 views
Looking for help on why my n-channel mosfet is getting destroyed
I've got a design that I've inherited with a pretty standard n-channel mosfet driving a relay that controls a motor and actuator.
On a recent build we started getting a 50% failure rate on the ...
3
votes
3answers
537 views
Simplifying a relay network
I'm currently trying to design a relay network for a piece of laboratory equipment (PPMS). I would like to describe what the setup is, what I am doing now, what I hope to do, and how I hope to do it. ...
1
vote
2answers
1k views
Driving a single-relay board with Raspberry Pi
I have one of these single-relay boards and I am trying to control it with my RasPi's GPIO. (I'm a complete noob).
I am using WiringPi and in this particular case I'm using pin 1 (aka BCM pin 18) as ...
1
vote
3answers
347 views
Turn on a relay when the output is high
I purchased a 5V 8 channel realy to use with Arduino.
When the output is low the relays are on. I need to turn the relays on when the output signal is high.
Is there a way to make the board respond ...
3
votes
1answer
112 views
Solid State Relay Question
The solid state relay board functions normally by shorting + to input, but latches closed on device side of the relay until load is turned off or is disconnected.
Is this normal for solid state relays ...
-5
votes
1answer
56 views
Subject Selection [closed]
'Utilizing Electrical Energy' or 'Protective Relay' which subject should I choose in my 5th Sem in Electrical and Electronic Engineering. Help me giving me advice on this topic.
5
votes
1answer
214 views
What's the easiest way to create a software-controlled 220V electricity interruptor?
As the title says, I'm looking for an easy way to interrupt a 220V electrical cable and to write a software that controls the interruption.
I imagine there are some kind of relays or contactors which ...
0
votes
1answer
250 views
how many light bulb for one relay?
i've just done this tutorial: http://www.arduino.cc/es_old/Tutoriales/Rele
it works great! i've done it in a breadboard (with two 5v circuits for test) and then soldered (for just does not have 220v ...
2
votes
2answers
179 views
Creepage and clearance when using relays
I'm looking at this 10A, 277VAC relay and wondering if there is sufficient spacing between the low voltage (3.5V, 100mA) and the high voltage(277VAC, 10A). The foot print looks like this:
Are the ...
6
votes
3answers
3k views
In a circuit being switched by an NPN transistor, do power supply and input need the same ground?
I'm trying to make a circuit that will allow me to switch on a relay that will turn on an LED. However, the relay is rated for 12 V, and I only have an input of 5 V, so I'm using an NPN transistor. to ...
7
votes
2answers
941 views
Why did relay run when I applied half the nominal coil voltage?
I'm using a RadioShack 12V DPDT relay, model 275-249.
I applied 6 V across the coil and the switch closed. Why is this? I didn't have any resistors in series with the 6 V power supply (the only ...
5
votes
2answers
400 views
Controlling a power strip with a toggle switch. Flight sim design
I am building a cockpit. It will function basically as a flight simulator but for a different game. Mechwarrior online. a Mechpit. Here is my problem.
Toggle switch 1 when flipped on turns on the ...
1
vote
2answers
318 views
Is the garage door open? Reed relays [duplicate]
Possible Duplicate:
How can I detect if a garage door is opened or closed?
I'm planning to make something to detect if our garage doors are opened or closed. We have a server where I'm ...
3
votes
3answers
907 views
Shift Register output to Relays
sorry for the length.
This is a continuation of my recent question. I have an optocoupled 8-relay board that I’m trying to connect to my microcontroller. I have placed a 74HC595 shift register inline ...
1
vote
2answers
161 views
Possible Relay Overload
I'm currently using the following opto-isolated relay board: URL
Everything is working correctly, I can switch on and off a small light without any problems. Now as soon as I plug in a larger load ...
1
vote
2answers
146 views
Different design in relay load connections
(I know, relay are drawn in the wrong way, NO contacts should be in serie with load, I'll fix it ASAP)
When I have to build a board to switch many devices (mains powered), I always use a single ...
3
votes
2answers
3k views
Selecting the right relay
I'm looking for some advice on what type of relay I should use for my circuit.
I have a 5v power supply and I want it to act just like a switch. I will be controlling it with an Arduino like ...
0
votes
2answers
1k views
GPIO remote switching PC on/off
I saw a post on raspberry official forum. It's about GPIO remote switching PC on/off, but it is not very detailed. I am pretty interested in it and i have this relay. I am wondering if anyone here has ...
3
votes
3answers
1k views
BJT, resistor, and diode work but ULN2803 does not
I am trying to control some 5V relays with a mC. At first I went with using a BJT, a 470 ohm resistor, and a 1N4004 diode to control each one of the relays. Each mC output pin is 5V, 40ma. This ...
1
vote
2answers
192 views
Relay power supply
The reason I am writing is I was curious about hooking up a higher external power supply, Can I hook up a 120v to the 4channel 5v relay module? or does it have to be 5v. I am trying to only use my ...
-3
votes
1answer
88 views
Relay current question
For the 16 CH 12V Relay module, does the output currency mean that we could run 5VDC, 12VDC or 24VDC through the relay? What ever current we input will be the output current, correct?
-2
votes
2answers
889 views
relay connection, how?
I got this on hand http://www.sainsmart.com/arduino-pro-mini.html, how can i connect my Arduino Uno to control it?
Can someone help with an example connection provided to the Arduino side to control ...
1
vote
2answers
692 views
8 channel 5v relay
I bought an 8 channel dc 5v relay module for Arduino from an on-line store. When i power on my system, the modules become really hot.
My connections are,
Vcc to 24vdc
Gnd to ground
In(1-8) to the ...
0
votes
1answer
695 views
Sainsmart relay output wiring
I have a 2 Relay module from Sainsmart. http://www.sainsmart.com/arduino-pro-mini.html/
The output has 3 connections instead of just 2. I want to know which two of these three connections I need to ...
1
vote
2answers
180 views
Using relay to control
Using a relay, if I found a 12v source on the ps3 motherboard that was on only when the ps3 was on. Could I attach a 12v relay switch to it and the connect some LEDs that run off another power supply ...
4
votes
2answers
1k views
Driving Solenoids from Arduino
I was wondering what the best way to run a solenoid would be from an Arduino board. I was thinking about using a MOSFET that runs into a relay to turn on the solenoid but am not sure how to go about ...
0
votes
1answer
445 views
How to connect a SPCO relay?
I have a relay SRM-1C-SL-5VDC. I am trying to switch the load On/Off using this relay. I am not sure how to connect it correctly as there its not mentioned clearly in the datasheet. Which pin on the ...
