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Adjustable 0-5v ground switch

EastonS

New Member
Hi everyone I am new on here and only getting my toes wet with electronics. But I want to build something to switch a ground for a solid state relay. I have a 0-5 coming from a laser and when it reaches a gives height it will trigger the ground on the ssr I would like to have a rotary potentiometer to tune it.
any help with this would be fantastic.
thank you. Steve .
 

EastonS

New Member
I am Hoping to be able to use the 0-5v output from the laser and then used the potentiometer to control at what height it will tigger the ground on the solid state relay.
 

Visitor

Well-Known Member
Exactly where is the output coming from? A laser wouldn't typically have any output signal.

Is the output coming from some kind of sensor? It sounds like you need a comparator circuit to switch when the output of a sensor reaches a certain level.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
You can build what you want from standard industrial control part, but it won;t be cheap. They USUALLY need a 24V supply.

See:


the DC limit module and the potentiometer module are two devices that could be used.

The IAMS module https://www.redlion.net/products/in...rol/signal-conditioners/iams-universal-inputs with dual setpoints might do exactly what you want. I have one in my possession that I'm going to use for a home project.

This unit uses a universal supply. You can set the units to your own engineering units, set hysteresis etc.
It might not be a good one for fiddling. You need a programming interface which gives you a display which can stay attached.
There is an RS485 interface as well available.
 

EastonS

New Member
Exactly where is the output coming from? A laser wouldn't typically have any output signal.

Is the output coming from some kind of sensor? It sounds like you need a comparator circuit to switch when the output of a sensor reaches a certain level.
thank you.
yes it is a sensor. I would like to switch when a get a certain output but I would like to have a pot or something to be able to adjust exactly when it switches the ground to trigger the solid state relay.
the relay is latching so I only need it to activate and then when I cycle the power it will unlatch the relay.
 

Visitor

Well-Known Member
Something like this comparator module will do what you need. Look at YouTube for a comparator tutorial to explain how it works.

Screenshot_20210412-071315_Edge.jpg
 

atferrari

Well-Known Member
What "trigger the ground" means?
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
lots of room for interpretation here:

Guesses:

There is a 0-5V signal involved
An SSR is involved
A potentiometer is involved

Are we turning on the SSR at some value of V?
How often is the fixed value changed?

We really don't care about the laser EXCEPT for the fact that it could be safety issues?

Are we dealing with an Set, adjust, forget type of issue or fiddle with the adjustment many times during the day?
 

EastonS

New Member
To make is simple.
I have a 0-5 v signal. At 4.5v I want to trigger a ground.
The 0-5 is coming from a sensor.
I have 12 v supply
The ground is to trigger a ssr.
 

atferrari

Well-Known Member
Unnecessary fancy nonsense.
 

KeepItSimpleStupid

Well-Known Member
Most Helpful Member
That "ground" has to sink how much current at what voltage?
Is that voltage AC or DC?

Then operation wise:
How often is this 4.5 V adjustment going to be made?

It's the difference of taking a voltmeter and setting the voltage with a trimmer and then put the voltmeter away,

Could be a turns-counting dial and a display.

Could be a display in engineering units?

Could be a Up/Dn pushbutton sort of thing?


Do you want it to be a commercial product?

Here https://www.aliexpress.com/i/32947646340.html is a place to start.


Here https://www.aliexpress.com/item/329...earchweb0_0,searchweb201602_,searchweb201603_ is a real example of what you COULD want?

You'll have to wait for it.

Just a note, 0-5V can be "hard" to come by because with a 5V supply and no trickery, you can't get to zero and you can;t get to 5V. getting to a few hundred mV of the rails is easier.

We go with real specifications, not made up ones.

We can take the programming design approach where you propose a system based on loose specs and then ask questions.

Resolution plays apart of it too. 4 to 4.9V could give you better resolution if you need it.

Thanks for the 12V supply being available.

process control stuff generally will work, but that stuff is rugged and EXPENSIVE.

How fast the signal needs to be generated may matter.

The process control module IAMS with limits MIGHT work for you. It will take 24VDC or AC power, do engineering units, do the "alarms" all in one module. You just don't want to change the value every day.

Your "block diagram" consists of a:
A reference
A buffer
a potentiometer
A comparitor with/without hysteresis
The output z of your signal matters. If it's 100 ohms or 1M, it makes a difference.

Getting that 0-5 reference is tough. Getting a 100mV to 4.9V is not as hard.
 

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