Controlling the supply to a Hall effect Sensor (A3144E) with another A3144E

Irving

Joined Jan 30, 2016
4,009
Is the solenoid a 2-position latching device or spring-biassed so requiring power to be applied to maintain one position? I'm guessing the N52 you refer to is a magnet and you want to switch the solenoid on or off with the magnet - by its presence or its polarity?

Do you have a specific hall effect sensor in mind? Most simple hall effect devices output 2.5v when no field is present and 0.2v for a S-pole and 5v for a N-pole, so some additional logic needed unless you can guarantee magnet polarity and strength.


Edit: Missed the A3144 reference in the title doh!
 
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Alec_t

Joined Sep 17, 2013
14,390
Do you actually have the A3144E's ? When I checked for a datasheet it seems the A3144 is no longer in production (although advertised by online sellers via Amazon), and has been replaced by the A1104.
Googling "latch circuit schematic" will get you plenty of examples of latch circuits.
 

sghioto

Joined Dec 31, 2017
5,424
As the title states; what would be the most effective way to latch the transistor "closed" using the output from another "always on" sensor - then have it turn back on by biasing the transistor the other way again, using yet another sensor?
Is this what you are trying to accomplish?
H1 activates the solenoid and Q1 performs the latch.
H2 is powered through Q2 and resets latch.
1676822960627.png
 

Thread Starter

Buster710

Joined Feb 18, 2023
64
Is this what you are trying to accomplish?
H1 activates the solenoid and Q1 performs the latch.
H2 is powered through Q2 and resets latch.
View attachment 287887
Could be the ticket! Thanks; that's super helpful.
It gives me something to go off at least.

Any special consideration for the resistor values? Or just calculate using V=IR as usual?

Also, am I right in saying that were the sensors in the diagram momentary push buttons, it'd operate the other way around, seeing as these sensors provide a "negative" signal, or am I mistaken? (EDIT, they seem to put out about 3v + on D.O. , not negative output.)

(It makes little difference to the operation of the thing, just for curiosities sake.)

A push button would provide a positive signal, iinm?
Or does it just depend on the polarity of the connections?
 
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sghioto

Joined Dec 31, 2017
5,424
Also, am I right in saying that were the sensors in the diagram momentary push buttons, it'd operate the other way around, seeing as these sensors provide a "negative" signal, or am I mistaken?
Not sure your meaning but a push button could provide either a negative or positive signal depending on how it's configured.
The hall sensors have an open drain FET transistor in their outputs which would be the same as a momentary switch with one side connected to ground providing a negative output.
 

Thread Starter

Buster710

Joined Feb 18, 2023
64
Not sure your meaning but a push button could provide either a negative or positive signal depending on how it's configured.
The hall sensors have an open drain FET transistor in their outputs which would be the same as a momentary switch with one side connected to ground providing a negative output.
Thanks for the help. That clears up a lot of questions I had.
 

Alec_t

Joined Sep 17, 2013
14,390
The Skinner device has a claimed 1200% energy increase and is a scam. Any 'over-unity' device is a scam. By all means build a latching circuit for your education, but don't expect free energy.
 
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