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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9 views

Implementing a safety lockout through ladder logic

The family fireworks show has become my soon-to-be brother in law's and my "thing" over the last couple of years. We have some ideas to make the show better next year, my part is spinning up some ...
2
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0answers
11 views

Can I use the Omron G6RN relay where reinforced insulation is needed beetween coil input and switched circuit?

I want to use a relay to control 230V power to an electric motor. I'm considering using the Omron G6RN relay: http://datasheet.octopart.com/G6RN-1-DC24-Omron-datasheet-10910301.pdf According to the ...
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1answer
35 views

16 channels relay control with 3.3v pins

I'm going to buy two 16 channels relay boards from Sainsmart : http://www.sainsmart.com/16-channel-12v-relay-module-for-pic-arm-avr-dsp-arduino-msp430-ttl-logic.html I want to control it with a ...
0
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1answer
22 views

Autoelectrics: Testing components off 12v battery

I'm quite good with mechanics and am just starting to learn more about electrics specifically applicable to automotive. One thing I am still yet to get the grasp of is the way electricity behaves. It ...
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1answer
76 views

Relay or Transistor for DC Resistive Load?

I'm building a circuit that includes a resistive load that I have to switch, which is going to be supplied with ~200 VDC and 0.1 Amps. I've looked at different mechanical relays, and typically they ...
-2
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0answers
40 views

DPDT relay for making mr mirror move up,down,left and right [on hold]

I'm supposed to install a mirror on one of our helicopters and it has to move up, down, right and left. The mirror company provided us with two DPDT relays. I'm using a four way switch with the center ...
0
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2answers
60 views

What do these symbols in ac connectors stand for?

I'm trying to use a relay to control my house lights with a electronic circuit. I'm familiar with 5V DC circuits, but I've never played with AC before. My relay has three connections, which I assume ...
2
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2answers
53 views

What are the differences between an AC and DC coil relay?

If a DC coil was just a coil, it would saturate. If an AC coil was just a coil, the magnetic field would drop to zero at 120 Hz and the relay would chatter. Presumably the designs in some way prevent ...
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0answers
32 views

what should the specifications of relay be for the circuit?

I want to use relay to switch the 'live' line of the ac supply. The coils of the relay will be controlled by a microcontroller pin through an optocoupler. The normally closed pin of the relay will be ...
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1answer
49 views

Help with On/Off Flip Flop Switch

I'm still fairly new to electronics and have been teaching myself as a hobby. Currently I'm working on a project that detects a red laser beam, and once detected will turn AC lights OFF if they're ...
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2answers
146 views

SMD vs THR Transistor for Relay

Designing a Relay control from a MCU's GPIO, there are some requirements to take into account. Coil Voltage: 3V Coil Resistance: [36-45]Ohm Relay Voltage: 250Vac // 30Vcc GPIO Voltage: 3V3 Max GPIO ...
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2answers
60 views

Why does my solid state relay not properly power a DC load?

I'm using a T108S02 to try to use a logical signal to turn on or off a small 3V DC toy. I'm not sure of the load current of the toy since my ammeter is not working. When I activate the relay, my toy ...
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0answers
26 views

Using Optoisolator to Control a Toy

I'm trying to control Tweet Monkey (http://codefoster.com/tweetmonkey) using a optoisolator. It's a 816S, but it looks like the specs are identical to the more popular PC817. I have an Intel Edison on ...
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3answers
79 views

Why do designers use a series diode and zener for coil suppression rather than just a zener?

I understand the use of the Zener but what I don't understand is one topology uses two components, but why can't the other topology be used ? simulate this circuit – Schematic created ...
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2answers
64 views

Relays in series to handle initial short circuit

I'm trying to design a circuit to turn on and off an electrical 230V 1A 1-phase motor using a relay. I'd like to design it such that if the user inadvertedly short circuits the output, the relay is ...
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2answers
87 views

How to drive relay using uln2003 [closed]

I am designing a IR base home light control. for this i use 6 relays and i try to driver it through uln2003. I connect the GND and COM wire with 12 volt power supply and input pins are connect to ...
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3answers
52 views

Starting the 5.5kva Kipor diesel generator from a distance

How can I start my kipor 5.5kva diesel engine generator from a distance of about 30m? I would like to avoid going outside my house to access the ignition key panel but just start from the comfort of ...
2
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2answers
47 views

Relay Isolation

I have read on many websites to use a separate power supply for relay only. But I've few questions. Can I use some component instead of using a separate power supply ? Or what would really the problem ...
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2answers
48 views

Confusing relay rating [closed]

I have this relay and the ratings are quite confusing - 10A 30v and 10A 28v, I'm confused as to why there are two. Could anyone please explain it to me. Thank you
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2answers
81 views

Need a switching device. Should it be a relay?

I am trying to build a system where first i would charge the battery (3.7V,40A), and then discharge it through a high wattage Resistor. For this purpose i will be connecting a power supply (15V-50A) ...
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3answers
61 views

How to avoid Relay buzzing noise? (LDR dependent)

I have the following circuit where I'm switching a relay based on whether it's day or night. I made a voltage divider using a pot and an LDR, which leads to the NPN transistor. So when it's dark the ...
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0answers
20 views

Vakind 4 Channel Relay Contacts not closing

I have a Vakind 5V 4 channel opto-isolated relay breakout (http://www.sainsmart.com/4-channel-5v-relay-module-for-pic-arm-avr-dsp-arduino-msp430-ttl-logic.html) An Arduino Mega2560 is driving the ...
3
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3answers
239 views

Determine adequate speed of flyback diode for a relay

I have already looked at this question which looked like it would provide the answer: How to choose a flyback diode for a relay? But it didn't, so I also checked out these: ...
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0answers
34 views

Actuate a 12 v relay with audio signal

I was trying to actuate a 12 v ready when my phone rings through the audio 3.5 jack; knowing that when it rings the volt is raised from 0 to .7 volts. and I need to protect the phone from the circuit ...
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3answers
69 views

Solid state relay doesn't turn off

I am trying to build a custom light setup for my computer desk. I want to use the scroll lock LED signal to control a pair of 12 volt DC CCFL lights run off the same inverter. The problem is when I ...
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1answer
52 views

Reed relay driving motor getting stuck

So, for a project I'm using a light sensor to switch on a relay which drives a motor, as seen in the pic below Q1 is 2N2222A NPN transistor, Q2 is an NPN phototransistor, R1 is a 100k pot The ...
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1answer
52 views

Need advice on my simple solar powered lighting system

I'm building a simple circuit in which a solar panel will charge a 12 V battery during the day and then switch over to battery power during at night to light up a few bulbs. I'm using an LDR which ...
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1answer
40 views

Relay not switching [closed]

I just built a circuit which switches between two DC lines using an SPDT relay with a common load. I connected one source directly to the coil terminals and also as one power supply to load .Initially ...
3
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2answers
81 views

Is a flyback diode necessary when no sensitive chips are used?

I have had a look through all the information available about flyback or snubber diodes in a relay system and was hoping to confirm if one is necessary in my circuit or not. All the info about why a ...
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3answers
126 views

Relay Spike at Vdd

I have a problem with voltage suppression at the time of relay switching. I use a transformerless ac to 12v dc conversion circuit similar to (I use 12V zener and 470uf capacitor) : ![enter image ...
0
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1answer
50 views

Switching 12V/6A with an AVR - MOSFET or relay or both?

I want to control the 12V heating of an oxygen sensor with an ATmega328P. It draws about 6A when switched on when it is cold and about 1.5A at the operating temperature of 350°C. It is powered with a ...
1
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0answers
61 views

Automatic Power Input Selection - Home Automation (mini)-Project

I live in a developing country where electricity is not available 24/7; however, to compensate for the power outage, I have 2 other incoming power lines from third-party generators. The thing is, ...
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1answer
119 views

How to make a high current bi-directional motor driver circuit

I have a 14.4V DC drill motor that can draw 10 amps when under full load. I need a circuit that can control the speed and direction of the motors, using an Arduino with PWM. We are using relays ...
0
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4answers
96 views

find VCC, GND and IN in relay

I`m new to electronic stuff, I was reading an artice on how control AC light using arduino, In part of solution there is a relay module which has a VCC and GND and IN and COM and NO and NC, but I ...
0
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1answer
58 views

How is debounce achieved in (EM) relay?

I was reading theory that: A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as ...
4
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2answers
145 views

Why do I need this relay?

Hopefully I don't get torn apart for such a noobie question (but how else do you learn right?). I got a Raspberry Pi to hopefully learn a bit about electronics (and because it was 35 dollars). I asked ...
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1answer
39 views

Exceeding Relay contact voltage

I've a relay with Maximum contact voltage of 24VDC @ .5A. Switching capacity of 12W. So can I use the relay contacts for 110VDC and 5mA. As it is much lower than the Switching capacity. If it can ...
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2answers
48 views

Teledyne relay 420

I'm using teledyne relay 420 in our project. Can anyone help me out with its pin functions and connections? The datasheet is here http://www.teledynerelays.com/pdf/electromechanical/420422.pdf ...
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1answer
33 views

working of Relay switch for driving high voltage ac appliances

Explain the working of relay switch for driving high voltage ac appliances? also explain how it works in embedded system?
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2answers
65 views

Voltage and Amperage in relays

i have a relayset for Arduino where i find these numbers on each relay: 10A-30VDC 10-28VDC Now, id like to connect that relayset with external devices that run 12V and all the way up to 35A. I was ...
3
votes
2answers
55 views

Relay noise problem although flyback diode is used

I've this relay (5V) with 1N4148 as flyback diode across the relay's coil but there's still noise problem. When I switch on/off the relay, the PIC MCU will occasionally reset and false triggered the ...
2
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1answer
68 views

thyratrons or vacuum tubes for relay control

I am trying to build a tube amp without using any semiconductors (just for the fun of it, trying to make it using the technology that was available when tube amps were mainstream). I may need to ...
0
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0answers
33 views

Beginner needs help - Rpi controlled lights question

I'm currently working on a home automation project and I've came across a roadblock. Hopefully someone can tell me if what I want to do is possible and maybe point me in the right direction. This ...
0
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1answer
37 views

Simultaneous operation of inverter and diesel generator in a solar system

I have a problem at one of my on-grid solar system project. There is a problem which lets the solar inverter on, when the grid is off and the diesel generator is on. As you know that, the solar ...
1
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2answers
117 views

Designing PCB with Multiple power supplies

This is my first REAL project and i need some help. I'm working on a project where I am trying to design a PCB for controlling the environment inside an enclosed cabinet to grow a tomato plant using ...
0
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1answer
47 views

Construct a relay circuit?

I need to construct a circuit with 4 relays that implements the functions $$f = xy+x'y'$$ and $$g = x'y + xy'.$$ I know that x'y + xy' = (x + y)(x'+y'), but does this help?
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2answers
50 views

Inductance of a relay coil

I'm using a magnetic latching dpdt relay from Teledyne company. The value of inductance for the coil in the relay is needed and not given in the data sheet. The part number of relay is 422d from ...
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0answers
17 views

Confirming the use of a RIFA snubbing component across 120V relay switch

I have a mains relay switch (Packard C230B 2 Pole 30 Amp Contactor 120 Volt Coil) which allows me to turn on my pre-amp based on the existence of AC voltage on the amplifiers AC output plug (which is ...
0
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2answers
57 views

Can a malfunctioning relay in an amp cause or allow a speaker to crackle when turning the vol potentiometer? [closed]

Ok, so this question has several layers, I admit it. I recently acquired a Lepai 2020A+ amp. It is, I believe, the latest version PCB because it has the two relays for speaker protection instead of ...
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0answers
23 views

Measurement of 230VAC relay noise

I have an MCU which is switching a load, which is connected to 230VAC via a two pole relay switching live and neutral. The load is another MCU board with its own ACDC. My problem is that when the ...