A solid-state relay (SSR) is a switching device that accepts a small control signal to control a larger load current and/or voltage. In many ways they perform the same function as an electromechanical relay without any moving parts, they have many advantages but also some disadvantages compared to a ...

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3
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2answers
91 views

When/where to open and close a transformers output

I came across Beware of Zero-Crossover Switching of Transformers (TE Connectivity App Note) where they discuss about how you shouldn't switch a transformer at the zero crossing because it would have ...
1
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0answers
41 views

Connecting/disconnecting AC signal via uC

I want to mix up to four AC signals, that may or may not be DC biased, but will always be between -5.6 and +5.6. For that I was going to use a summing amp. (If anyone wants to talk me out of that in ...
0
votes
1answer
59 views

Relay Solution for Controlling Pumps with Arduino

I'm working on a hydroponics project that requires me to run 10 pumps for 15 seconds every 2 minutes. I was able to set this system up by running a relay board off of an Arduino, but the relays were ...
4
votes
6answers
220 views

Parameters when choosing a relay

Is this a good circuit to use as a air condition switch with a help of microcontrollers 5V? What relay to use in this situation? What parameters should I take into consideration when choosing ...
0
votes
3answers
62 views

Solid State Relay operation

A solid state relay specifies a trigger current of "7.5mA/12V". How much current does it draw at 5V? This is the relay. I'm controlling it with an Arduino which has a maximum current draw of 40 mA ...
1
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1answer
51 views

How can I switch two wires using solid state relays?

I want to add a "reverse" function to a brushless motor ESC - in theory, it can be done by simply switching any two of the three output wires - I would like do to it via solid state relays, but I am ...
-2
votes
2answers
56 views

Charging 2 different age batteries using a battery isolator in my vechicle [closed]

I am interested in using a battery isolator, specifically this battery isolator, in my van to charge a deep cycle auxiliary battery using the vans alternator. I would then like to use that auxiliary ...
-2
votes
1answer
36 views

Will a 3-32 VDC input signal relay be damaged (or will work) with a 110 VAC input?

I'm looking at getting a SSR-25DA relay (http://www.amazon.com/gp/product/B0087ZTN08/ref=ox_sc_act_title_1?ie=UTF8&psc=1&smid=A1THAZDOWP300U) and using it with a temperature controller that ...
1
vote
1answer
30 views

SSR selection - how is on resistance related to output IV curve?

I am looking at the datasheet at the link below, and I can't for the life of me figure out what I am missing. http://www.digikey.ca/product-detail/en/TLP3542(F)/TLP3542F-ND/871299 This is a Toshiba ...
1
vote
1answer
42 views

Solid State Relay Input Resistor

I have a set of solid state contactors that I want to turn on and off with 24v PLC outputs. That contactor takes 4.5 - 15V inputs ( Changing the relay to the 24v input model is not an option right ...
0
votes
2answers
65 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 ...
0
votes
0answers
21 views

ULN2003 similar circuit for 120VAC device

I am looking for an integrated circuit which maybe similar to a ULN2003 in the sense of being able to control multiple high power devices. I want to control 8 120VAC solenoid valves with an arduino ...
0
votes
3answers
75 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 ...
1
vote
5answers
133 views

Creating DPDT Solid State Relay with FETs

I feel like this should be a very simple question but so far I have not found a solution. My goal is to make the following DPDT relay circuit using MOSFETs: The goal is to connect INX to OUTX or ...
1
vote
1answer
48 views

Switch high frequency AC on/off at zero crossing

I have a 3 phase generator which is powering some system. (50Vrms @3A, with variable frequency from 50-5KHz). I've used mechanical relays to control each phase to the load. However, there was no real ...
0
votes
1answer
121 views

Using a Normally Closed PCB mounted Solid State Relay

Summary: Continuing my search for a solution to my problem, I have landed on normally closed solid state relays (NC 1 FORM B SSR). Could you tell me if I'm doing this right? What I need: What I need, ...
1
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0answers
55 views

Calculating signal attenuation for AC?

So we've got this; simulate this circuit – Schematic created using CircuitLab Which I've been told is equivalent to the sum of it's Coutputs to an AC signal; simulate this circuit ...
0
votes
0answers
53 views

Changing the resonant frequency on the fly?

So I have a coil and a default capacitor, they resonate at 150kHz. I have these three SSRs in place, they "add" a capacitor into the circuit. Here's a simplification of one switch; simulate ...
0
votes
0answers
58 views

Please help me with my capacitance-adding circuit

It's to add capacitance to a little tesla coil, (Bigger schematic, right click > open in new tab to view full size) Please note, I removed the capacitor and resistor on the gates. For some reason ...
0
votes
0answers
28 views

How to power multiple different LED light strips with a single adapter [duplicate]

I am building a fun electrical project soon using up to 16 LED light strips and I am having worries on either breaking them or under-powering them. The project takes in MP3 audio files and uses a ...
0
votes
1answer
86 views

Distortion in ADC output

I am working on Intel Galileo board and using its one ADC pin (A5) and one digital GPIO pin (pin 8). I am switching a relay from GPIO pin and using ULN2003A for isolation and LM60 temperature sensor ...
0
votes
1answer
86 views

Do we have a SSR relay technology that can stand 100 switching per second for a long time?

Are SSR relays capable of switching on/off 100 times per second for a long time? For example 1 hour? Does this affect the longevity!? I want to use relays for 5vdc control and 12vdc output with very ...
0
votes
0answers
48 views

Mechanical Relay Alternative for Switch 15A at 120VAC

I'm using 2 of these relays in a design, K10P-11D55-12 (http://www.digikey.com/product-detail/en/K10P-11D55-12/PB327-ND/254544). They're really the only ones that suit my needs but they're pretty ...
5
votes
3answers
617 views

What is the difference between a solid state relay and a transistor?

Along with the difference between a solid state relay and a transistor, I'm also interested to know if there are transistors that act a lot like the typical relay modules you can find on ebay (where ...
0
votes
1answer
158 views

Microwave Oven: Switching Magnetron (Transformer) with SSR [closed]

I've got a used microwave oven and want to improve it with a digital user interface. Is it ok to switch the magnetron (more precisely: the transformer from 230V 50Hz to some kV followed by a diode ...
1
vote
0answers
65 views

Interleave two analog signals

I am trying to interleave two similar but not identical pass-band (analog) signals (i.e., both have a center frequency of 15 MHz, and a bandwidth of 200 kHz) on a sample by sample basis. The idea is ...
0
votes
2answers
80 views

Can Solid State Relays be used “anywhere”?

With mechanical relays, they can be inserted anywhere in a circuit. Can SSRs be used anywhere in a circuit or are there certain gotchas that exist ? Consider this simple example where SW* is a SPST ...
0
votes
1answer
73 views

Is this SSR design recommended?

I want a hard power switch for some battery-powered BLDC motors, but the currents (5A, up to 20A transients) and voltages (up to 60V) limit the kinds of switches I can use. Because I want some small ...
0
votes
2answers
113 views

How to use a solid state relay in a dip package to drive a 24 vac relay

We have a fan coil unit in our server room where I work that utilizes a microcontroller to control temperature and humidity. I have an HVAC and electrical background so I am familiar with ...
1
vote
0answers
44 views

Solid state relay (optocoupled triac) is extraordinarily hot when on

I am using the following part: 3-32VDC input to 240VAC max 40A, KD20C40AX, that is connected to an Arduino Uno that drives a 5V control signal to the opto. The application, (output/triac side), is ...
1
vote
1answer
68 views

Solid state or Mechanical relay

I need to control a load that uses 20A at 110v. Should I use solid state or mechanical relay? Mechanical relay's contacts can lose conductivity over time due to high current and high voltage, I am ...
1
vote
1answer
66 views

Is there any way to use an ac load ssr with a dc load

i have a s202s01 relay that i want to connect to my microcontroller. The problem is that the load i want to control is a DC source. Is there any way to make that ssr (3-24dc, 8A 250VAC) work with a ...
1
vote
3answers
63 views

Guitar pickup / PhotoMOS off-state leak

Brand new member here. I'm using an AQY211EH PhotoMOS relay to switch guitar pickups via an Arduino, as shown below: This works great, with one minor exception: even when no power is applied to ...
0
votes
0answers
77 views

Low cost solutions for reversing 130VDC 20A motor

I have a treadmill motor controlled by an MC-60 controller board. The motor is reversible and I want to control the direction using an Arduino. The catch is that it's 130VDC and 17A (the voltage ...
0
votes
1answer
150 views

Connecting SSR relay

I bought a cheap SSR relay (SSR-40DA) on ebay and like to connect it directly to arduino, Schematic on website (http://www.fotek.com.hk/solid/SSR-1.htm) shows that LEDs already have resistors in the ...
0
votes
1answer
40 views

What should a ture RMS Voltage meter read on the load side of a zero fire SCR?

I have a 3 phase zero fire SCR/SSR set that has 480V input. I put my Fluke 289 (which is a tRMS meter) across the different phases on the load side. Then adjusted the output. The voltage read ~470V ...
-1
votes
2answers
73 views

Possible solutions instead of 12 relays

First of all i am new to electronics, but have some basic idea. I want to create a USB switcher with arduino, which will control "where" the usb device is plugged in, instead of unplugging and ...
-2
votes
2answers
311 views

Need circuit to Switch 240v a.c. mains with 3v or 5v

I have the IRFP460 power transistor which if I understand correctly can switch 20A/500V on 20v input. I am wondering what a circuit design would look like that would allow me to either (a) switch ...
0
votes
1answer
61 views

Fuse and AWG choice for immersion heater circuit

I am planning to operate a 1500 W resistance immersion heater with an SSR and I'm trying to determine which fuse and AWG wire to use. The 1500 W heater on 115 VAC should operate at a current of around ...
0
votes
1answer
251 views

Using two Mosfets for AC

Im having trouble getting my head around using two mosfets to pass AC. I have reduced my schematic to its bare bones to help keep it un-cluttered. The aim of this circuit is to use PWM to dim a bulb ...
1
vote
4answers
189 views

What kind of component would I need to put a break in a RS-485 bus?

I'd like to have some kind of electronically controlled switch (transistor, relay, solid-state relay, etc) that acts as a break in a RS-485 bus. The effect I would like is to optionally split the bus ...
1
vote
2answers
97 views

SSR with low-flow switch to control heater

I'm trying to install a low-flow switch (circuit is open below 0.1 gal/min, closed above that) as a safety measure on an immersion heater, but I have some questions about the setup I've come up with ...
2
votes
1answer
255 views

Verify relays soldered onto a circuit board

Hello I need to verify a couple of relays for proper functionality. They are soldered onto a PCB as shown in the attached image - labelled RELAY 1 and RELAY 2. Online tutorials take a stand-alone ...
1
vote
2answers
106 views

100v audio source volume control / distribution

I have an audio signal from a class-d 100V and 500W. amplifier. I want to distribute this to 16 different sets of speakers and control the volume of each set individually. I am unable to find any ...
0
votes
1answer
416 views

Switching frequency of a solid state relay?

I bought a SainSmart 4 channel solid state relay recently. I am planning to use an Arduino to control some Christmas lights I've put up around my home. My question is: How fast can you switch SSR's on ...
1
vote
2answers
244 views

Solid state relay (or equivalent/alternative) to drive 6V DC from a 3.3V micro

I have to open/close two wire from a closed device. I cannot open due to it's under warranty, and the only part that I can open and modify is an external button that connects the two wires. Firstly I ...
0
votes
3answers
303 views

Should I use a snubber or solid state relays on a 24 vac circuit?

I'm trying to create a smarter controller for my hydroponic systems. I have an arduino controlling a sainsmart mechanical relay. The load on the relays are 24 VAC orbit sprinkler valves. Everything is ...
0
votes
0answers
104 views

Flyback (?) diode on the Solid State Relay output

I am looking at the recommended wiring diagram of this SSR and I am wondering about the diode connected in parallel to the load. Flyback diodes for inductive loads make perfect sense to me, but in ...
1
vote
1answer
137 views

Problems getting an SSR to turn on

Has anyone had problems getting a solid state relay to work? EDIT: see Spehro Pefhany's answer. Lessons learned: don't accidentally take out current limiting resistor solid state relay rated for ...
1
vote
1answer
62 views

Increasing the current to a solid-state relay?

I've got two strings of LED Christmas lights that operate at 120 V / 0.04 A (4.8 W). I'd like to connect them to this 5V solid-state relay: Unfortunately, there's one small problem. According to ...