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Does a current activated switch as small as an OR Gate exist? Answered

I have a type of connector that has two wires. two on one side and two on the other. One of the "connectors/wires" is red with ~5V and the other is white with a varying current/voltage of ~10mV to 3.3V which goes in either direction.

This connector is meant to be plugged in, in either direction. So at any given time, only one side is receiving current. The bottom of the connector if thought of as a box comes into contact with a grounding panel, which shorts out the connector, and it does not function.

What I need is to have a sort of switch, that when activated by current, can "turn" off the bottom pins when plugged in one way, and then the other pins when plugged in another way.

I have thought about it and I can use a simple OR Gate, for the constant 5V, but OR Gates will not work going in two directions or at a varying voltage of 10mV to 3.3V.

I was thinking that perhaps a current activated switch would work, but it needs to be a very small chip, and relatively low cost. Anybody have any ideas? Sorry for the poor picture. I am not an artist. ;) Thanks, in Advance. -Sterling


Triacs, they are like an AC Silicon Controlled Rectifier, or an AC on off switch.

Something, I should have mentioned is that the connector is DC. Thank you, Josehf Murchison.


Answer 5 years ago

Hey, do you know if DC TRIACS would would work better or the same as Solid State Relays?

Basically, all you need is 4 diodes in a bridge rectifier. Use schottky barrier diodes.

Someone else I talked to mentioned using diodes for the 5V contact in place of an OR Gate (which I did not realize had to be powered.) If I were to use the diode's for the second pin, how would the bridge rectifier fit in? I apologize for being a bit of an electronics novice. Thank you for your reply.

I think we need more of a diagram of your intentions.

Thank you steveastrouk, for looking at my problem. Okay, so I uploaded some newer and more refined images/diagrams.

It is difficult to understand, I realize. So basically, I have a connector which has two contacts on one side, and two on the other. This is so that is can be "reversible," or that I can plug it in either direction.

With the old set up I connected the correlating contacts to the wire which leads to the device (represented in the diagram.) I ran into problems because whichever contacts faced the bottom of the port kept touching the metal ground or shielding, and would not let my connector work. (It would short.)

This is where I thought an OR Gate would work for the red (5V) connector as then only the electrified contact would send the current on towards the device, and not short out due to OR Gate's channeling.

The next problem arises in how I can get the other contact which acts as data to function, as it varies in voltage and seems to go both ways, depending on whether it is writing or reading. Gates are one way, and I do not think can handle a vast varying rate of voltage.

I thought of perhaps using a relay, but I do not know if that is a small enough solution or what exactly to do. I am stuck.


Answer 5 years ago

Oh, and the grounding panel is represented by the grey color near the bottom of the labeled "PORT."

B far your best option is to make the plug a one way fitting so It can't be reversed. - Problem solved with a little sugru or shape lock and a bit of carving


Well the problem is I cannot further modify the port, or connection. The port is kind of standardized. I simplified the problem for Instructables, because it is hard to explain the rest of the set-up. However, I will remember that for another project I have going. Thank you rickharris.