The wife runs a small organic rice mill and we want to optimize the weighting process of finished packaging.

The scale can be preset to target weight and I can "harvest" a very weak signal of about 1 V and 40 mAmp (Signal is to make LED "weight reached" glow).

I need to use that trigger to open a compressed air valve. Valves are available in 12V, 24V and 230V with consumption of not more than 5W when triggered.

I am a food technologist and basically have no clue about electricity or electronics. 

My local electrician also waved the white flag.

In a Germany forum I read that a solid state relay like like this can be used but what I need is a complete layout for a solution that I can present to a guy in an electronics shop to solder it together. If someone can do me the complete solution I am happy to pay in money or barter for delicious Organic Thai Hom Mali or Organic Sticky Rice. Thanks for the input!

 

Edited November 8, 20178 yr by brufi

I can only guess that the 1 volt signal you found is across the led. The led would be removed and the output used to drive a solid state relay opto input which will then drive a 220v valve. These dc-ac relays are available as complete ready to use modules. Best to find a local electronics guy maybe TV repair shop or similar because someone needs to check if the signal you have found is suitable to drive a SSR.

Yup, chances are your LED has a series resistor, taking an output from the hot end of the resistor and the cold end of the LED should give you a signal that can drive one of these for a massive investment of $1.50.

 

This unit activates when the input is on.

 

https://www.aliexpress.com/item/5V-1-Channel-OMRON-SSR-High-Level-Solid-State-Relay-Module-250V-2A-For/32783530819.html

 

 

 

 

Thanks maxpwer and Crossy,

The exemplary Omron Unit has voltage in of 4-6V whie I have only one V, I have not found a SSR with input of 1V.

Will see if local TV guy can help...

3 hours ago, brufi said:

Thanks maxpwer and Crossy,

The exemplary Omron Unit has voltage in of 4-6V whie I have only one V, I have not found a SSR with input of 1V.

Will see if local TV guy can help...

 

Check at the other end of the resistor that's in series with the LED, I'll bet you have a 5V logic signal to play with.

 

 

While I wouldn't really recommend it, you could get an opto-sense circuit that would close a relay when an LED light is detected. 

 

The electronic voltage-sense circuit type Crossy suggested is probably much more reliable.

Ah. Systems integration. The bane of everyone's life?

 
Check at the other end of the resistor that's in series with the LED, I'll bet you have a 5V logic signal to play with.
 
 

That was the solution. We used the 5V logisch Signal. All good now. Thank you All for the input.

Sent from my SM-A730F using Tapatalk