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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86 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 ...
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3answers
77 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 ...
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2answers
45 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 ...
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1answer
39 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 ...
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2answers
60 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 ...
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1answer
85 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 ...
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2answers
82 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 ...
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1answer
76 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 ...
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47 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 ...
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1answer
48 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 ...
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1answer
52 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 ...
112
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5answers
10k views

Designing a Santa alarm (honestly)

You read the title and that's what I am trying to do. Synopsis: I have a young son who is determined to catch Santa (to what ends I don't know). He even dreamed up using some kind of pressure plate ...
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1answer
122 views

Solid-state relay realized with bipolar transistor

I'm searching information about SSR realized with bipolar transistor. Basically I need something like tutorial how they are constructed, how they work, what elements they contain etc... I searched in ...
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1answer
71 views

1V output only when load is applied?

I'm working with the Teensy++ 2.0 dev. board. It uses the AT90USB1286 8 bit AVR 16 MHz microcontroller. I'm using the microcontroller to drive a small solid state relay. This was just a basic ...
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2answers
160 views

Do I need zero-crossing detection for controlling a heater?

I need to control a heater element (about 500W) using arduino. For switching part I would go with zero-crossing SSR or zero-crossing optoisolator and triac (the second seems to be cheaper). The ...
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0answers
78 views

LTSpice missing an SSR Component?

I want to simulate some circuits with SSR component but LTSpice does not provide this. From Eagle and KiCad I learned I can create my own component diagram. I'm not sure if I can do this also with a ...
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3answers
68 views

Making my own kotatsu

I want to make my own kotatsu (a small table with an heating element underneath) and I'm considering using a "heat lamp" as the heat source (one of those aimed at reptiles, fits in a normal light bulb ...
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4answers
159 views

Relay alternatives that are silent and support 500mA+

What can I use as a silent "general-purpose" relay alternative? There are various scenarios where I will need a relay-like device that allows me to control one circuit with a separate isolated ...
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1answer
56 views

What's wrong with my static relay connections?

Im trying to use a static relay for the first time. It is an HFS5, supposed to turn on/off at ~5V. Soldering is not clean but I have triple checked with a multimeter that the connections are ok on ...
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1answer
118 views

Normally closed SSR won't work with grounding out a magneto's primary to ground

I've been trying to find a device that will ground out a magneto's coil (primary kill wire) in a normally closed state without using a mechanical relay because I want my circuit to be all solid state. ...
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0answers
40 views

Mounting SSR + HEATSINK

I have made a AVR based Bluetooth mains controller. The idea is to be able to control my AC using my phone. Since I would be controlling an AC, I figured I would be needing a solid state relay with ...
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0answers
85 views

Dimming SSR Circuit - Verification

I am designing an SSR circuit for the purpose of controlling Christmas lights. Specifically I have the following two goals. Switching & Dimming incandescent strings Switching LED strings - I ...
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3answers
87 views

Can I use this relay for DC

http://www.dx.com/fr/p/ssr-25da-25a-solid-state-relay-white-134494#.VDmPWPl_uap It says AC output but how can this transform DC to AC ? Shouldn't this act like a switch ? If my circuit is DC and I ...
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1answer
128 views

AC AND DC Solid State Relay (SPDT) Circuit?

I have been looking to replace this SPDT switch with a solid state relay. However I learned that the switch could either have a 120VAC or 30VDC or even be used to switch an input on the controller to ...
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1answer
84 views

What kind of protections are needed to control an AC motor (230 V) using a microcontroller?

I need some guidance with surge-protection of the SSR and also how to safely bring the motor to stop (since it's an RL load, the inductive current has to die out). I found a schematic online, but have ...
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3answers
194 views

Standard Relay vs SSR vs TRIAC for Switching CFLs

I'm confused weather I should go for a standard electromechanical relay (EMR) or a sold state relay (SSR) to switch CFLs @ 220V with 100W max load. This is for a commercial product with the following ...
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1answer
226 views

Solid State Relay Capacitance Bad for Audio?

Regarding MOSFET optocoupler relays like the Panasonic AQW212, am I correct in understanding that the capcitance between the terminals and ground when the switch is open ("off") is around 100pF when ...
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3answers
365 views

Solid state circuit to charge caps in parallel then discharge in series?

Do there exist a solid state design circuit to do the following: Charge multiple capacitors in parallel for a certain amount of time from a low voltage DC source, then disconnect them completely from ...
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3answers
299 views

Protecting Solid State Relays from Short Circuits

I have 4 SSRs on my board with a steady state current rating of 2A and a peak current rating of 9A (Relays are CPC1976). This product is meant to be a commercial one and the relays will be powering ...
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2answers
81 views

Using triacs to switch more complex equipment than just motors and lights?

Obviously triacs have been well known to be used in applications which don't really require a perfect sine wave to function. However, what about say a triac to switch on and off more complicated ...
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4answers
339 views

Using an SSR photoelectric sensor with Arduino

I'm wondering if I can use this photoelectric sensor with an Arduino. I don't have much experience with these sensors or with relays, and I'm sometimes confused by output switch ratings, so I can use ...
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2answers
93 views

Voltage drop problem with my solid state relay

My solid state relay seems to be dropping the potential by 35 volts. I read about 80 volts from one end of a modified plug and the other end is plugged into a 120 volt wall socket. I have the hot ...
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1answer
45 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 ...
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2answers
224 views

Solenoid stays on when output turned off

I have a power supply with 12V running into a the common on my PLC. Output 0 on the PLC is wired into a solenoid. The negative on the solenoid runs into the ground on the power supply completing the ...
2
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1answer
374 views

Is it possible to turn an audio signal ON/OFF using a solid state relay?

I'm thinking about controlling an audio signal (turning it ON/OFF) using a solid state relay switch? Is that even possible? If not, is there a different or easier way to do this? I'm a noob in the ...
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0answers
73 views

Choosing a SSR for CFL (Peak Current Rating)

I have to choose a solid state relay to switch some CFL lamps. The particular lamp is a 85W CFL (this is the actual wattage and not a comparison to Incandescent) which has a turn-on characteristic as ...
0
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1answer
40 views

What determines the communication speed? is it the physical link's speed or the communication card speed?

Two IEDs (Intelligent Electronic Device),an electronic relay and a gateway, are connected with Modbus RTU protocol over RS232. In the relay's manual it states that a speed of 9200 bauds can be ...
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2answers
141 views

Controlling Solenoids using Relay vs Transistor

In several examples, relays were used to control solenoids, others use the transistor. In my question, I'm looking at controlling 24VDC solenoid pneumatic valves. What are the advantages and ...
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2answers
403 views

Driving a contactor from TTL

I have 7 contactors that need to be controlled remotely (a permanent installation). These are controlled with 240V AC and, according to specs, uses 9.2 VA of power when turning on and 2.7 VA of power ...
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1answer
200 views

Which transistor should I use in place of a 5V relay to adjust brightness of lights (230V) with the Arduino?

I want to control brightness of lights (230V) with the Arduino, and I know that relays will just switch the lights on/off. If you have the circuit or any idea about which transistor to use and how to ...
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4answers
404 views

Can this 12VDC Relay be used for Switching 24VDC?

Can the Songle srd-12vdc-sl-c relay be used with 12VDC on its output? On top of the relay, it writes 10A 28VDC.
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1answer
169 views

Driving a load with 1.8V input

I have a Gumstix expansion board and want to make it communicate with some 24V PLCs. I've read these topics for reference: 1.8V to 5V, still not comfortable with transistors Transistors: why are ...
2
votes
1answer
216 views

How can I control brightness of a CFL with a microcontroller?

I'm new to electronics and just turned on and off appliances with an Arduino and relays. Now I also want to control the brightness of a CFL with an Arduino as I controlled the brightness of a LED. So ...
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2answers
178 views

How to wire this relay (silkscreen in Chinese!)?

I have the following relay and am unsure of how to wire it since the silkscreen is in Chinese :-/ Datasheet. I'm finding the datasheet difficult to interpret, but from playing around with my ...
0
votes
1answer
375 views

Arduino SSR 5V DC (Mager GJ-3FA-L)

I just noticed this SSR that was for DCV instead of all the others that are normally for AC. Although I can not find the datasheet for it, it does seem compatible with Arduino. eBay auction site ...
1
vote
1answer
143 views

Does low frequency PWM create reactive power in a transformer?

I got a 350VA transformer (230V~/24V~) which is directly connected to a heating unit at it's 24 V ends. The 230V end of the transformer are connected to 230 V~ mains over a solid state relay (SSR). ...
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2answers
95 views

5v contact closure SSR?

I want to have a contact open/closed when a USB port is powered on or off. When monitoring the USB port with a multimeter it takes >1 minute for the voltage to drop from 5v to zero. What is a simple ...
2
votes
2answers
153 views

Solid State Relay “fading” instead of dropping secondary voltage

I am using a (rather cheap-ish) chinese solid state relay (ssr) with 5V DC on the driving, 230V AV on the driven side (there's an ATtiny85 randomly letting devices run for 10-30 minutes, then cuts the ...
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2answers
119 views

Violation operating temperature

I have a problem on my current project. Relays are failing in Cold temperature. I am using a relay which has an operating temperature +85C to -25C to PCB. And my device under test is at -40C. Can ...
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2answers
142 views

Is there such a thing as a wireless solid state relay

I want to control multiple baseboard heaters in my house, but I don't want to put a raspberry pi connected to a solid state relay behind each baseboard heater, or even connect it to the thermostat, as ...