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

learn more… | top users | synonyms

0
votes
0answers
19 views

PSC motor driver circut using relay

I am working on a project in which i need to connect Permanent Split Capacitor(PSC) AC motor using relays as shown in the below block diag fig 1. I want to rotate it in both CW and CCW direction. It ...
0
votes
1answer
34 views

How to use LM56 to switch on/off a 2kW heater

I have an oil heater at 220V/2000W so lets say 10A. I was thinking of creating a circuit to switch the oil heater on/off with a LM56 (http://www.ti.com/product/lm56). Is it possible using a relay or ...
0
votes
1answer
22 views

Remote Wireless 4CH Switch On/Off - Data PIN Network Cable

Planning Stage I'm in the planning stages of making a wireless on/off switch that will basically cut off pin 6 on a network cable. I know little about electronics and I've attempted to learn as much ...
0
votes
2answers
82 views

Timed LED circuit with ATX PSU, help

I want to make a circuit that turns on and off the light (LED) of a given time (eg. on 9 pm and off 6 am). I also want it to be adjustable. My idea about the design: I will be using an ATX computer ...
0
votes
0answers
55 views

Switching a relay through a wireless connection

I want to create a circuit which will wirelessly drive a relay. I only have a little experience with Arduino. I know what peripherals I need, but I don't know what micro-controller to use. I made a ...
1
vote
2answers
166 views

Power switch with slow control signal

I am trying to switch on and off a circuit that draws about 0.8 amp at 12 V. The obvious choice is to set a MOSFET. The problem is that the control signal (the one that goes on the gate of the MOSFET) ...
0
votes
3answers
61 views

SPDT Relay with 8Pin

I needed a SPDT relay with 240Vac so I bought this relay from Maplin http://www.maplin.co.uk/p/15a240vac-spdt-miniature-relay-n07aw But I am heaving problem to wire this relay because it has 8 pins ...
0
votes
0answers
6 views

Wiring Relay & Horn on Golf Cart [migrated]

I've had this wired up in the past but I forget how it was done and some things came apart. We have a simple 12v horn and relay. The relay is a KUMP 7D58-12. Here (http://imgur.com/a/dtBFo) are some ...
0
votes
2answers
29 views

Control automotive AC switch via TPS voltage

The A/C compressor is engaged via a single wire that comes from the 'A/C' button on the dash board. I want the A/C button to disengage when the throttle is at 50%. The throttle position sensor (TPS) ...
0
votes
1answer
55 views

Controlling a bank of relays

I have a project that requires me to control a set of relays (up-to 24 of them). The current setup is using Wago Speedway 767 field-bus modules. I'm just ramping up so I have to either figure out how ...
2
votes
1answer
65 views

Contact arcing, how to avoid?

Recently my water heater's thermostat failed. It's just a simple mechanical one, with a piece of metal that "pops" and connects or disconnects the heating element. I would guess that what made it ...
1
vote
4answers
75 views

Triple pole triple throw relay

I have a turntable which rotates cw and ccw. This turntable is rotated by AC synchronous motor of 230V. I want to be able to rotate the turntable with Arduino. For this reason I need to control the ...
4
votes
3answers
186 views

Thermistor control of peltier voltage with Arduino (for DSLR chill box project)

I am mildly familiar with electronics, mostly from playing around with electronics kits as a kid. That was a long time ago, though, maybe as much as 20 years ago. I am currently working on a cold or ...
1
vote
2answers
95 views

Relay specs Question

Can anyone explain to me why there are 2 maximum voltages/amperage for both AC and DC like below ? 10A 250VAC 10A 125VAC 10A 30VDC 10A 28VDC I was thinking that the one on the left is for ...
-1
votes
1answer
43 views

Can a 2W supply power the Relays

I'm designing my first circuit with 2 relays JQX-15F / 005-1Z1 NO20A/NC10A 240VAC(datasheet, probably the SPDT variant) and a 2W ...
0
votes
1answer
29 views

Can TPS3700 undervoltage overvoltage monitoring IC drive relay directly?

I am new to electronic circuit design. My current project is to monitor biasing voltage for under/ over voltage using IC from TI: TPS3700. If any of the under/over voltage occurs I will need it to ...
-4
votes
0answers
77 views

I am trying to create a pulse circuit with a 24Hz/0.6 duty cycle, a voltage somewhere between 1.5-9v and an amperage between 50-100mF using an arduino

I am trying to create a pulse circuit with a 24Hz/0.6 duty cycle, a voltage somewhere between 1.5-9v and an amperage between 50-100mF. So far, I've tried using an Arduino to fire a relay (using the ...
0
votes
3answers
105 views

How can I add a power-off delay to this circuit

This may seem simple but I am trying to learn EE. In the below circuit, how can I add a delay when the button is released the relay will stay energized for approx. 5 seconds. My Circuit: ...
0
votes
1answer
49 views

Timed Relay Circuit Wiring and Calculating

I am trying to learn electronics and I have a simple circuit in which a button is pressed, a capacitor is charged, then triggers a relay. (With my limited knowledge) I am using a 4.7μf cap and a 470K ...
-1
votes
2answers
63 views

Latching Relay Driving Idea

I need to drive a 9V latching relay with single cell lipo 3.7V battery. So I designed a boost convertor. It brings 3.7V to 9V and than drive the latching relay with H-Bridge. But with this design so ...
0
votes
1answer
63 views

Help using less pins controlling 8ch relay

I know this has been answered somewhere but can't find the solution online. I have an 8ch 5v->120VAC relay controlled by arduino and need help using less digital pins. All channels need to be ...
1
vote
2answers
131 views

Power transistor or relay?

I'm going to use a microcontroller to switch a vehicle horn on and off intermittently for maybe one second on and one off for a period of 15 seconds; the horn will pull an estimated 3 Amps. I know I ...
1
vote
2answers
90 views

Circuit to switch off circuit “B” for 2-3 seconds when circuit “A” is switched off

Am really a noob in this regards, therefore, need help to build an easy 12V circuit which when circuit "A" is powered off enables "B" circuit to switch off for 2-3 seconds and then turns on. Hopw I ...
1
vote
1answer
65 views

How to make a simple Video Switch?

I thought making this would be simple, but I've found it a lot harder than I anticipated! What I mean is that I have one screen/monitor, and two video players (all video is through RGB component, RCA ...
0
votes
2answers
63 views

Switching a SPI chip between two devices?

I'm working on a project where it would be very handy to be able to automatically switch a SPI flash chip between two different devices (a programmer, and the system that's actually using it). ...
0
votes
2answers
125 views

Transistor as switch between similar voltages

I want to use an XBee to relay data coming from a serial device. The XBee will be sleeping most of the time; waking at regular intervals, powering on the serial device, relaying the serial signals, ...
1
vote
2answers
109 views

Flyback Diodes and Relays

I'm wanting to use a relay as a SPST switch, and I've noticed many designs incorporate a flyback diode. What instances are these needed and what are potential drawbacks, if any?
0
votes
2answers
69 views

How to protect bistable latching 2 coil relay with diodes?

I know that a revers diode is required to protect a DC coil relay. But to protect this relay RT314F05? It has 2 coils, are 2 diodes enough?
1
vote
2answers
82 views

raspberry pi relay

I'm trying to make the Raspberry Pi controlled relay. Searching the internet the whole day, I still cannot get it to work. ( I did not even connect it to the GPIO yet, just using the 3.3v rail). ...
0
votes
0answers
30 views

UPS relay circuit

I have acquired about 500amp hours worth of UPS type deep cycle batteries. I am looking to build my own UPS/Charge circuits. (I hope) To charge: I plan on using a standard 110V mains powered battery ...
0
votes
5answers
110 views

H-Bridge out of 2 (1 PNP, 1 NPN) Darlington Arrays

I need to control, with a µC, 4 single-coil latching relays and I am exploring various options. My first bet would be a H-Bridge. Since H-bridge ICs are quite expensive and are mostly designed to ...
0
votes
2answers
59 views

Alternatives to relay/contactors in DC circuits

I wanted to switch a 60Vdc line to ON/OFF using a 60Vdc controlling signal for some kind of a feedback system (yes both are 60Vdc). Presently I have two options visible: Solid State 60Vdc input ...
0
votes
0answers
67 views

DC Voltage of a 12V AC transformer after rectification

I want to drive relays using Method 2 of the following question: What is the most economical way to drive an array of single coil latching relays? This basically means that any time the relay is ...
1
vote
1answer
76 views

Use a relay as a resettable fuse?

I was thinking; If a relay is used to power a circuit AND itself, if the circuit is shorted - the relay should lose its own power and turn off - almost like a resettable fuse. To power it up, I would ...
3
votes
2answers
155 views

Replacing a FET to avoid the body diode (audio switching)

Here is a circuit I've found online for switching a guitar signal, it uses a mechanical relay in order to rout the signal through a sound processing unit or around it, bypassing the circuit. ...
-5
votes
1answer
82 views

What are the components on this schematics?

I would like to know the name of the components of this circuit. I want to build an automatic door system.
0
votes
2answers
81 views

12 V relay instead of 9 V?

My RC car uses 2 relays (9 V, SPDT) for it's forward/backward movement, as image below indicates: However, RC car isn't able to be driven anymore. Specifically, servo works fine but motor can't ...
0
votes
2answers
57 views

How should I understand this twin coil relay pinout? (Screenshot)

I'm currently looking on an automotive twin coil relay. The Datasheet gives me following schematic: My Question is: How could I test this relay? In other cases I put the corresponding Voltage on ...
1
vote
3answers
59 views

What are the pins for in this Relay module?

I am trying to figure out how to use this relay module. There is no datasheet that I could find for the whole module, there however are for individual box. Here is the picture below, there are three ...
2
votes
2answers
188 views

Creating an opto isolator board for Raspberry Pi

I have a relay board which I bought from dx.com and I am not sure about its reliability. If it fails, then it may harm my Pi right? So I googled around and read that opto isolator provide complete ...
1
vote
3answers
96 views

Powering multiple relays

I'm trying to control five * 5v relays from a micro-controller. However I'm having issues powering more than two at a time Some notes The power source is a 800ma 10V ac adapter. 7805cv voltage ...
0
votes
0answers
45 views

Mono-stable trigger circuit (monoflop) with start delay

I'm sorry if this question is a duplicate, but I'm not sure about the right terminology (in english) about my problem. I've got a device which operates at 13.5V. I want to switch this device with a ...
0
votes
2answers
96 views

Relay module without pinout diagram

I bought this 1 channel relay module but the board doesn't have any marking on it. Can someone tell me which pins are power, ground, relay on/off signal etc? Photograph of module: edit: traces
2
votes
1answer
87 views

What does the number of parallel lines in a relay symbol imply?

Some relay cores are represented by two parallel lines and others by three. Does the number of parallel lines have any significance? Saw this symbol in Tiny cad. What does three parallel lines in ...
1
vote
1answer
40 views

Ensuring an SSR relay is dead

I recently purchased a used IEC Centra centrifuge with a refrigeration feature. Works great, except the refrigeration condenser never cycles off and as a result the chamber gets down to the minimum ...
0
votes
2answers
111 views

How to calculate the required base resistor for this BJT-relay circuit?

I'm trying to design a relay circuit for my first PCB and have come up with the following: The 10K value for R7 is just a placeholder. R7 is what I'm trying to determine. The transistor should ...
-2
votes
1answer
103 views

220v/5v relay stucking problem

I am a beginner. I am having a problem with a 220V/5V relay. It works when I try it out of the circuit, but when I connect it to a 220V source and try to switch it, it stays stuck and doesn't move. ...
0
votes
0answers
41 views

Use a small circuit with +i, 0 -i to control current in larger circuit

I have a remote control with a three position switch - forward, neutral, and reverse that controls current in a small circuit, corresponding to +i, 0, and -i current. There is enough current and ...
1
vote
2answers
125 views

Should a rectifier or TVS diode be used as a flyback diode?

I'm trying to design a circuit for a relay similar to the following (except using SMT components): When I went to Mouser to try to find a suitable SMT diode to use in place of the 1N4001, I noticed ...
0
votes
2answers
87 views

Why is my simple relay circuit only half working?

I am new to electronics and I am following the book "Make: Electronics" by Charles Platt. I have built a circuit with a 12V DC power supply, a 1K resistor, a relay, two LEDs, and a momentary-on ...