Your link is wrong. It says the sensor is a Hall sensor but then goes on to describe an inductive sensor. A Hall sensor is a semiconductor device.

Les.

Hi Les, yes - some semiconductors use Hall effect to control circuitry. The device I refer to uses the original effect Hall discovered of the interaction of a moving magnet with a conductor. But this is irrelevant. My question is - how best to amplify the voltage signal to operate a relay ie which opamp/comparator circuit to choose, as there appears to be many available. I am looking for the simplest solution.Thanks.

 

Tach-generators or tacogenerator was a common term for devices that were often seen in some of the first CNC machines, one common manuf was Servo-Tek.
https://www.servo2go.com/suppliers/servotek/

 

Hi Les, yes - some semiconductors use Hall effect to control circuitry. The device I refer to uses the original effect Hall discovered of the interaction of a moving magnet with a conductor. But this is irrelevant. My question is - how best to amplify the voltage signal to operate a relay ie which opamp/comparator circuit to choose, as there appears to be many available. I am looking for the simplest solution.Thanks.

I would think one solution would be via a voltage comparitor?
LM311 etc?

 

If you want someone to design the circuit for you (Rather than just suggest possible methods to implement the device.) you will need to confirm that both the solenoid and the relay coil are powered with 12 volts DC and tell us how much current they consume.

Les.

 

Re question in #4
A smallholding or smallholder is a British term for a small farm operating under a small-scale agriculture model. usually just involving family labour

 

Tach-generators or tacogenerator was a common term for devices that were often seen in some of the first CNC machines, one common manuf was Servo-Tek.
https://www.servo2go.com/suppliers/servotek/

so what?

 

Re question in #4
A smallholding or smallholder is a British term for a small farm operating under a small-scale agriculture model. usually just involving family labour

this is irrelevant to this thread

 

You appear annoyed that I was just replying to two questions asked??

 

If you want someone to design the circuit for you (Rather than just suggest possible methods to implement the device.) you will need to confirm that both the solenoid and the relay coil are powered with 12 volts DC and tell us how much current they consume.

Les.

12vdc @ 1 amp

 

Is the 1 amp for the relay coil or the solenoid ? We need the current for BOTH items individually. If the solenoid only takes 1 amp we can drive it directly with a power mosfet. (This would mean that you do not need to use a relay.)

Les.

 

I am attempting to design a safety stop device for a machine that I use on my smallholding.

What is a "smallholding" ?

After several posts ignored the question, Max answered...

Re question in #4
A smallholding or smallholder is a British term for a small farm operating under a small-scale agriculture model. usually just involving family labour

this is irrelevant to this thread

Since I thought a smallholding was completely different than what Max clarified, I'd say it was completely relevant to this thread! Especially since you framed your initial question with the term in the use-case of your initial post (see bold-underline above)!

by the way, welcome to AllAboutCircuits.com

 

After several posts ignored the question, Max answered...


Since I thought a smallholding was completely different than what Max clarified, I'd say it was completely relevant to this thread! Especially since you framed your initial question with the term in the use-case of your initial post (see bold-underline above)!

by the way, welcome to AllAboutCircuits.com

Where this machine is used is IRRELEVANT - it was mentioned as background information. I am asking for advice about an electronics solution to control a machine that has a rotating element. Please forget SMALLHOLDING-sorry I mentioned it!

 

Where this machine is used is IRRELEVANT - it was mentioned as background information. I am asking for advice about an electronics solution to control a machine that has a rotating element. Please forget SMALLHOLDING-sorry I mentioned it!

Ok, but since you did, some people were wondering if it was a relevant part of the question or not. Like, is a small holding a part of a lathe and we might be able to interpret that your rotational inertia is small but must still be accounted for, vs a device for reattaching the wing of a gnat in which case, the rotational inertia might be much less to stop but the hair-thin wires in such a microscopically small device might still be fused.
so, now that you said it can be ignored, could you help me get the idea of Gnat wings out of my head?

 

It's really quite simple,
he wants to keep it a secret, so I guess it will remain a secret.
There is avast wealth of knowledge here,
if he thinks that he knows better, then I suppose he will do as he pleases,
no one here has any obligation to anyone else.

If the Thread Starter would simply show some slight consideration towards the people
attempting to assit him, he would be rewarded with many experienced viewpoints.
.
.
.

 

I never cease to be surprised that those that come to forums such as this to seek help, can take on a truculent attitude to those that are trying to help.
I for one would be willing to offer ideas and time based on many decades of designing, maintaining & modifying industrial machinery .
But in light of the OP posts so far, it seems non-productive , therefore I bow out.
good luck.

 

Is the 1 amp for the relay coil or the solenoid ? We need the current for BOTH items individually. If the solenoid only takes 1 amp we can drive it directly with a power mosfet. (This would mean that you do not need to use a relay.)

Les.

Thanks Les-this is the only sensible suggestion I have received on this site! Had a quick look at MOSFET stuff. I need one of the depletion type devices, as I need it to power up a solenoid when the voltage signal to the MOSFET goes to zero ie a N.O type switch. Ebay have loads of sellers of these devices at very good prices. Now just need to select the best one for this job.......any suggestions?

 

Calling everyone who has participated in this thread incompetent,
not providing any pertenent information when asked,
and just generally being rude,
will probably result in no further replies.
.
.
.

 

Calling everyone who has participated in this thread incompetent,
not providing any pertenent information when asked,
and just generally being rude,
will probably result in no further replies.
.
.
.

hello all-all of this is not true-this guy is just a trouble maker!

 

Thanks Les-this is the only sensible suggestion I have received on this site! Had a quick look at MOSFET stuff. I need one of the depletion type devices, as I need it to power up a solenoid when the voltage signal to the MOSFET goes to zero ie a N.O type switch. Ebay have loads of sellers of these devices at very good prices. Now just need to select the best one for this job.......any suggestions?

The tachogenerator I intend to use is showing an ac output (frequency dependent on rotation speed - think). Some research indicates that an ac input is OK if not exceeding approx 15v, so a MOSFET should be fine as I will be below 10v. Looks like I need to operate one in p channel and depletion mode to act as a N.O switch. Now looking for a suitable candidate.

 

Now looking for a suitable candidate.

While doing that also look for your "push solenoid". They are available but limited in what they can move and the force they can make. You will find most solenoids are of the pull variety.