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Topic: SSR relays not flipping (Read 643 times) previous topic - next topic

TomGeorge

#15
Sep 17, 2020, 05:34 am Last Edit: Sep 17, 2020, 05:35 am by TomGeorge
Hi,

Code: [Select]
int ssrControlPin = 30;
void setup() {                
 // initialize the digital pin as an output.
 pinMode(ssrControlPin, OUTPUT);    
 digitalWrite(ssrControlPin, LOW); // set the SSR on
}

void loop() {}

Does setting output LOW supposed to activate the SSR?

Forget Eagle, use pen/paper and photograph your drawn circuit.

Tom... :)
Everything runs on smoke, let the smoke out, it stops running....

LeandroAR

#16
Sep 17, 2020, 01:35 pm Last Edit: Sep 17, 2020, 01:50 pm by LeandroAR
Hi,
The SSR is zero-crossing switching, not sure if  200mA is enough.
Have you got a lamp to try?
What is the load, resistive, capacitive, inductive?

Tom... :)
Tom, I'm flipping a 25W led panel lamp. I tried LOW and HIGH, but only the LOW makes the led on the SSR to light up. I have also tried 4x 25W led panel lamps (100W, almost 1A), nothing happens.

Are you saying on a 2A capable relay, I need a current larger than 10% of its capacity to flip it?

LeandroAR

#17
Sep 17, 2020, 01:40 pm Last Edit: Sep 17, 2020, 01:41 pm by LeandroAR
Your relays come with one of three possible input voltages. Look on the case for the input voltage of your devices. Can be 5 volts, 12 volts or 24 volts. All have the identical mfg. number, according to the data sheet.

Paul
Paul, I tried with 5V and 17V (both with reliable external power sources capable of 5A), nothing does the trick...

CrossRoads

Are these the SSRs on the board?
https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf
Can you read the full part number on yours?
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

LeandroAR

#19
Sep 17, 2020, 02:15 pm Last Edit: Sep 17, 2020, 02:17 pm by LeandroAR
Are these the SSRs on the board?
https://omronfs.omron.com/en_US/ecb/products/pdf/en-g3mc.pdf
Can you read the full part number on yours?
It's G3MB-202P.


CrossRoads

"I tried running the control signal from 5VDC to 17VDC, nothing."

These are 5V parts,  I wonder if you damaged something?
I see what looks like buffer circuits, or could just be LED indicator circiuts near the left side of the board.
Have you tried tracing those out to see what they do? Or does the board source have any info on those?

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

LeandroAR

#21
Sep 17, 2020, 02:46 pm Last Edit: Sep 17, 2020, 02:46 pm by LeandroAR
"I tried running the control signal from 5VDC to 17VDC, nothing."

These are 5V parts,  I wonder if you damaged something?
I see what looks like buffer circuits, or could just be LED indicator circiuts near the left side of the board.
Have you tried tracing those out to see what they do? Or does the board source have any info on those?


I applied 17VDC to one board only. All other 10 are intact. Specs say input voltage ranges 5-24VDC, so I assume no damage is done.

I didn't trace any of the components in the circuit path. I found a diagram on it.


Wawa

but the conductivity test on the AC screws runs at 682 (I get 0 using EMR).
What does that mean (682).
An SSR, like any other transistor, never fully conducts.

I'm flipping a 25W led panel lamp.
I tried LOW and HIGH, but only the LOW makes the led on the SSR to light up.
So the problem is on the AC side.
Time to see a real picture.
Leo..

CrossRoads

CH1 goes to an Arduino pin, 5V is where you connected the 5 to 17V, and Gnd is connected to Arduino Gnd?

PNP transistor, CH1 has to be Low to turn it on to allow current flow into Pin 3 (and the indicator LED) to turn the device on.
R2 will not left much base current flow, on the order of 0.5mA, so the transistor won't turn on hard, Vbe will be high, the diode D1 drops some of the 5V before the transistor.

Can you measure Pin 3 of the SSR to Gnd when CH1 is low and tell us what you see?
Measure the 5V pin also.

Transistor spec

https://www.digikey.com/product-detail/en/micro-commercial-co/MMSS8550-L-TP/MMSS8550-L-TPMSCT-ND/2827205
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

LeandroAR

CH1 goes to an Arduino pin, 5V is where you connected the 5 to 17V, and Gnd is connected to Arduino Gnd?
SSR CH1 goes to Arduino pin
SSR 5V goes to 5V bus (I removed the 17V from the wiring)
SSR GND goes to GND bus

PNP transistor, CH1 has to be Low to turn it on to allow current flow into Pin 3 (and the indicator LED) to turn the device on.
R2 will not left much base current flow, on the order of 0.5mA, so the transistor won't turn on hard, Vbe will be high, the diode D1 drops some of the 5V before the transistor.

Can you measure Pin 3 of the SSR to Gnd when CH1 is low and tell us what you see?
Measure the 5V pin also.

Transistor spec

https://www.digikey.com/product-detail/en/micro-commercial-co/MMSS8550-L-TP/MMSS8550-L-TPMSCT-ND/2827205
SSR pin 3 (CH1) to GND (when low) = 0 (full conductivity)
SSR pin 3 (CH1) to GND (when high) = 1 (no conductivity)
5V (on any pin) to GND (on any pin)= 4.99V measure
SSR AC side, port 1, conductivity between screw 1 and screw 2 when low, measures 657.
SSR AC side, port 1, conductivity between screw 1 and screw 2 when high, measures 1.

LeandroAR

I also removed the arduino from the wiring and left it like this:

SSR CH1 goes to GND bus
SSR 5V goes to 5V bus
SSR GND goes to GND bus

Even with this, the measures are the same.


Wawa

#26
Sep 17, 2020, 11:15 pm Last Edit: Sep 17, 2020, 11:19 pm by Wawa
SSR AC side, port 1, conductivity between screw 1 and screw 2 when low, measures 657.
SSR AC side, port 1, conductivity between screw 1 and screw 2 when high, measures 1.
Are you saying you 're trying to measure the AC side of an SSR with a DMM (ohm meter)?
Can't do that. It's not a contact, but some sort of transistor/diode volt-drop.
An SSR always has some remaining voltage across a "closed contact".
And it needs it's load interrupted (AC) to release.

This thread is getting weird.
What else are you trying to do, apart from switching a mains AC lightbulb.
Does a common incandescent light work? And the LED light not?
Leo..

Edit: I only see two wires connected to your relay board.
It needs a minimum of three. (5volt/GND/IN)

dougp

#27
Sep 18, 2020, 12:35 am Last Edit: Sep 18, 2020, 12:36 am by dougp
Edit: I only see two wires connected to your relay board.
It needs a minimum of three. (5volt/GND/IN)
Hard to see but if you look closely there are a RED and BRN wire at the upper end.





Edit: I like this new auto-image-include feature!
I don't trust atoms.  They make up everything.

No private consultations undertaken!

LeandroAR

Are you saying you 're trying to measure the AC side of an SSR with a DMM (ohm meter)?
Can't do that. It's not a contact, but some sort of transistor/diode volt-drop.
An SSR always has some remaining voltage across a "closed contact".
And it needs it's load interrupted (AC) to release.
Hmm, yes, I was. I thought it acted like a regular relay (EMR).


This thread is getting weird.
What else are you trying to do, apart from switching a mains AC lightbulb.
Does a common incandescent light work? And the LED light not?
Leo..
Nothing but switching AC lights. I never tested it with an incandescent bulb, I don't even have one. Does this mean this SSR cannot be used to switch LED bulbs?

Edit: I only see two wires connected to your relay board.
It needs a minimum of three. (5volt/GND/IN)
There are 3 wires, red = 5VDC, brown = GND, blue = CH1 to GND

WattsThat

#29
Sep 19, 2020, 07:04 pm Last Edit: Sep 19, 2020, 07:08 pm by WattsThat
As Wawa mentioned, you will not get a zero resistance across an SSR when it is on. More importantly, you're not measuring resistance on that meter setting, you're measuring voltage drop as the "diode" test function being used does not measure resistance.

The reading of 682 on the meter diode setting would indicate the SSR is switching on, that's the voltage drop across the triac, 682 millivolts is what you'd see for a typical silicon device.

You stated you where trying to switch 25 watt led's on and off but you never stated what their rated voltage was. If they are not rated at 100-240 vac, you cannot switch them with that SSR.

Nothing is adding up here. Have you actually trying switching a proper load on and off with the SSR?

PS: I have no idea how you're making the measurement that displays the 682 as the black meter probe is nowhere to be seen. Just another mystery that may never be answered.
Vacuum tube guy in a solid state world

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