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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Relay cross over for 1925-3-2 [migrated]

My amateur radio uses 1925-3-2 relays on the low pass filter board to select bands. This relay is no longer available. Is there a replacement ?? Thanks Dave
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3answers
59 views

Powering and operating dual electric linear actuators

I am in the process of building a height-adjusting desk. I am pretty good with computers (I'm a programmer), but I never learned much in the way of electrical engineering. I recently purchased two ...
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1answer
24 views

alarm with reed and relay switch with memory [on hold]

My teacher recently assigned a circuit for us to build on the breadboard; it has to include a relay, a button, and a reed switch. When the magnet is removed from the reed switch, the alarm would ...
2
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1answer
66 views

Relay for Intermittent Wiper Function

I want to add an intermittent function to the wipers on my 40-year-old car without any additional switches. The details of the wipers can be found here ...
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0answers
25 views

DMX passthrough with no power

I'm working on personal project that involves reading some DMX signaling, changing a value, and then re-transmitting. One of the things about DMX signals is that when there is no power to the device, ...
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1answer
51 views

Attiny85 water plant with mini water pump

I`m new to electrical engineering, so it's probably a newbie problem. I'm using a wall power supply(5V-2A) to power the DC Motor and the Attiny85. A C1 470uF to make the power more stable. I don't ...
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5answers
943 views

Why does a relay have a minimum applicable load?

I am trying to find relays for my application and I read a data sheet which looks fine but specifies Minimum applicable load: 10mV 10µA In my circuit, it is expected that the relay closes but no ...
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3answers
96 views

Looking for right component in my simple diagram

I am not electical engineer therefore stumbled upon this simple issue. In need to activate a 120VAC 1HP motor from sprinkler timer that has 4 individual channels providing 24VAC up to 400mA voltage ...
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2answers
50 views

Using a relay switch to switch power to solenoid

I'm fairly new to electronics, so I'm hoping I'm not so misguided that I am wasting all of your time. Basically I need to power a solenoid which in turn controls a gate valve, and the solenoid ...
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1answer
13 views

Automatic-switching reverse (back up) caravan camera

I'm wanting to try some electronics trickery after many, many years away from it. Unfortunately many of the rules evade me but I feel like I could pick it up quickly, again. My goal for my first ...
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1answer
63 views

Relay Contact Sticking Problem

In the Image... I am trying to put 30A 12V Relay OMRON G8P-1A4P 12VDC parallel to Push Start Button (Dual Starter control for 1HP Pump Motor). But every time relay picks up contact stick... Before ...
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1answer
41 views

Invert ground vs. open “signal” - relay?

first post here. I'm trying to design a circuit to invert a ground/open input signal. I.e., output is grounded when the input is open, and vice versa. I have a feeling this can be accomplished with ...
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3answers
97 views

One month timer circuit

I need to cut a signal wire after one month from it start working. So I am looking for timer circuit that it work by small battery make a short circuit for my signal wire after around ( few days more ...
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3answers
98 views

How do I use a 5V relay with a 3.3V arduino pro mini?

I'm using a couple arduino pro mini's (3.3V) for a home automation project and want to add relays to the final PCB design to switch some stuff on and off. Since I want to use a 5V relay like this: ...
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2answers
46 views

How does a time delay contact remain open

If input voltage energizes a repeat cycle time delay relay coil, and the contact closes thus energizing output to the load for t1, how is the contact is able to open after t1, if it's still energized ...
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2answers
51 views

Keep a Relay ON until Switch closes

Im trying to fix an egg incubator, currently has a mercury switch (when the temperature reaches two points on the glass, the mercury completes the circuit, it has small holes and some metallic strips ...
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2answers
47 views

easy way to switch a signal

I have below configuration: ...
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1answer
50 views

An help with my practice: a common relay as latching relay

I'm looking for some help, since, currently, I'm “studying” the latching relays. I am aware of the fact that exists pre-made latching relays of two categories: the first one with two coils: the first ...
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2answers
86 views

Why does relay switch cause change of voltage?

I am making an Arduino Thermostat. The arduino draws power from an adapter and the relay draws power from the 5v arduino. I have an LED that changes color according to temperature brackets. The ...
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1answer
30 views

Improve a simple “magnetic alarm” with a timer, to extend the ringing time

I've bought this simple "alarm" for a door: Which is internally provided with a reed switch; inspecting the internal circuit using a multimeter, I figured out that when the magnet is placed near to ...
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0answers
27 views

relay circuit needs reset each time activated

I am trying to activate a relay using a wireless doorbell. I managed to do it using attached circuit. I took the input signal Vin from the doorbell receiver circuit. I checked all points and found one ...
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1answer
64 views

Are relays appropriate? circuit review

I'm designing a circuit to drive two 12V dc motors. I've got two low current switches connected to relays as can be seen in the schematic. These are for power isolation and local motor isolation. Can ...
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1answer
68 views

Drive Bistable Single Coil Relay with two MOSFETS [closed]

I am currently in the middle of the a project where I need to drive a relay. Scavenging the parts I have around I have 2 STP55NF06L logic MOSFETs and a TE Connectivity PE014F12 Relay. I wanted to ...
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2answers
50 views

Conditional Relay trigger

I want to design a circuit to trigger a relay depending on the house current load: When current load is below 12A the relay must turn on and when current load goes above 17A relay must turn off. How ...
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2answers
70 views

What could be the reason for the relay output not turning OFF? [closed]

I bought one of these relays and got it working great. It worked for a few days brilliantly. Then I went to add more circuits to this relay, and since then, the outputs on all four relays do not ...
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2answers
337 views

switch on a long wire end causing microcontroller to shutdown

i've a push button connected to micro-controller using a 100m 18ga wire that cause the micro-controller to shutdown after few times of working properly the circuit is fully functional with a short ...
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2answers
55 views

Use of a capacitor to accomodate temporary voltage drop

I recently added a small circuit board to delay my car stereo powering up. The idea was to prevent the stereo coming on in the brief period between turning the key from ACC to START and back again. ...
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1answer
59 views

The diode and the relay question

Do I need to use a diode with the following setup ? What i want to do is activate a relay which then closes the positive side of a nema 5-15 portable receptacle and allows electricity to flow. When a ...
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1answer
84 views

Automatic switching of a constant current circuit

I'm running 14 ~3W (700mA) LEDs in series on a constant current LED Driver that handles between 36-65V output. The driver runs the LEDs at 600mA. The heatsinks I've attached are pretty small, and if ...
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2answers
94 views

How to Detect if Motor is not Working?

sorry for my english, I am from Indonesia. I try to make a (car) relay active - switch on, if the motor/fan is working normal, so when the fan is out, not working or broken, automaticly the relay is ...
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1answer
84 views

Which Switches Faster? Transistor, Solid-State Relay or Relay

Which Switching Device can Switch from Off to On and Off the fastest? Transistor Solid State Relay or Mechanical Relay
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2answers
93 views

Power MOSFET or Relay

I want to operate a 12V automotive fan with a 3.3V uC signal. The (37-year-old) centrifugal fan draws 3.2A for about 100ms at startup and then a steady 1.2A while running for a maximum of 30 minutes. ...
0
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2answers
64 views

Question about flow with relay and capacitor (Make Electronics-Charles Platt, Exp. 8)

I'm a newbie working my way through Charles Platt's Make: Electronics (2nd Ed). I'm on Experiment 8 and I'm confused about something. The circuit looks like this: What is supposed to happen is that ...
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1answer
58 views

USB GPIO board stops responding after high voltage relay with load is switched on

I'm using Numato 16 GPIO board to switch relays on 8 Channel Relay Module. Until no 220V load is connected to the relay all works fine and I can switch on/off relay using Serial port command to GPIO ...
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2answers
70 views

Navigation lamp monitoring circuit

I have been tasked with designing what is to me a strange circuit. I have to wire a 12/24 led navigation light with an 'on' indicator and an 'off/extinct' indicator. This is what i tried - switched ...
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3answers
102 views

how to close the circuit by relay with a pulse and my circuit stay closed until another pulse comes

I am new in this kind of stuff so please excuse me for my lack of knowledge and English Language :) I have an old car and I want to make a circuit with an LED that lights when car is switched ...
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2answers
86 views

How to fade in and out light bulb(220V) (Arduino)

I have relay conected with arduino and high voltage bulb, now how can I control voltage to fade in and out bulb? I know that a relay is an on off device so maybe a triac or IGBT would be needed?Would ...
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1answer
88 views

How to connect this Relay Module to printer port (LPT1)?

Hello, have this relay board, how can i connect this board to a printer port (LPT1) and can this port cope with the amps needed to drive the board? I am not an electrician, so please take notice ...
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1answer
52 views

Working principles of an LDR Light Switch

This is a simple circuit which dims the LED according to the light recieved by the LDR or simply a light switch. Can anybody explain how two BJTs opearete in the circuit, or simply how the system ...
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3answers
114 views

zener diodes, different voltages, and using a relay to control its opperation…will this work?

Ok so I am going to admit that I am an idiot when it comes to circuits. However, some advice would be appreciated with regard to my idea. I am trying to control two seperate circuits, each with ...
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3answers
86 views

Applying AC to a DC relay coil [closed]

I want to use a 24 V DC relay with 24 V AC. Will the relay stop working? Is it safe to do it this way?
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1answer
37 views

Can I convert a split phase motor to a permanent split phase one?

The induction motor I am using has a dead current relay and finding the part is proving quite difficult. The motor has neither a run nor a start capacitor. I am considering the idea of switching the ...
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5answers
178 views

Is it OK to use a lower voltage to operate a relay coil than rated coil voltage?

I want to know if I used a lower voltage than what was labeled on the relay was OK. The relay was a 24V relay. I check that the relay turns on when the voltage when the voltage was 13.5v. If I apply ...
0
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3answers
76 views

What is the purpose of a relay between a switch and motor?

I was disassembling a belt disc sander today and noticed that there was a rather large relay between the switch and the motor. The relay consists mostly of a large copper coil. The motor doesn't have ...
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1answer
84 views

Multiple Broken Relays — What About My Circuit Is Making Them Fail?

I recently purchased one of these relay boards ... to use along with my Raspberry Pi to switch an AC outlet on/off to control a fountain pump. Since the relay board requires 5V for the control ...
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1answer
55 views

Raspberry Pi controlled lamp using a relay & mains procedure

I am trying to turn on and off a lamp I have at home using a relay controlled by my Raspberry Pi. Here are the exact parts I will be using: Raspberry Pi B+ My lamp: My relays: Potential ...
1
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3answers
78 views

Inductance changes in DC relay coils

PWM operation of DC relay coils in order to save power while holding is now common. This is at a frequency that is high enough to avoid chattering or audible noise and low enough to not have to worry ...
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1answer
41 views

Is it mandatory to use a relay driver for analog application?

I am using a 5pin 6v relay in an analog circuit application. This is my first time to use a relay. I heard that there is a relay driver. Is it necessary to use a relay driver along with relay. Its a 5 ...
3
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1answer
53 views

How to delay a relay closing?

I have a situation where I'd like to delay the closing of an off the shelf relay by ~5 seconds. Assuming it is a 5V coil, and switching 12 V, I'd like the following: t 0:00: 5v applied to input, ...
2
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2answers
99 views

How to connect a relay to 220 Volts outlet?

I used relays before but just for simple 5V DC signals control using a Raspberry Pi. Now I'm quite cautious and would like to ask for some help from professionals because I'm not planning to set my ...