Hello,
I am working on my first simple circuit project. I am very new to electronics, but I have picked up a very basic understanding of general components and circuitry.
I have a few questions today. Below is a very basic schematic of my project. Don't worry too much about specific voltage/current quantities (I made the schematic very generic).
This is how it should (typically) work:
- Gadget 1 will turn on for a split second, allowing current to flow through the Optoisolator and activate Gadget 3.
- Then, Gadget 2 will turn on for a split second, allowing current to flow through the Optoisolator and activate Gadget 3.
Additional Info / Assumptions / Possibilities:
- Gadgets 1 & 2 can potentially power-on in any order, they could even turn on at the same time.
- Gadgets 1 & 2 can potentially remain powered-on for indefinite periods of time (seconds, minutes, technically even hours, etc).
Now, for my actual questions
As you can see, I am unsure as to what components I should insert into the two (-) return paths after the optoisolator. Do I need to insert anything? What happens if only gadget 1 is powered-on and current flows to both gadget 1 and gadget 2's negative terminals?
If that is an issue what components do I need to add at the (-) return paths? Simple diodes don't work because you know which battery the power is coming from at any given time. Is there a particular component that people use to solve this issue?
*Extra question:
Would a simple NPN transistor work as a replacement for the optocoupler? If I connect gadget 1 & 2's positive paths to the base of a NPN transistor it should allow gadget 3's current to pass across the transistor's collector and emitter. However, what happens to the the current applied to the base? I don't want that extra current flowing through the transistor into Gadget 3's sub-circuit.. do transistors allow the base current to flow out the emitter or what happens to it?
I am working on my first simple circuit project. I am very new to electronics, but I have picked up a very basic understanding of general components and circuitry.
I have a few questions today. Below is a very basic schematic of my project. Don't worry too much about specific voltage/current quantities (I made the schematic very generic).
This is how it should (typically) work:
- Gadget 1 will turn on for a split second, allowing current to flow through the Optoisolator and activate Gadget 3.
- Then, Gadget 2 will turn on for a split second, allowing current to flow through the Optoisolator and activate Gadget 3.
Additional Info / Assumptions / Possibilities:
- Gadgets 1 & 2 can potentially power-on in any order, they could even turn on at the same time.
- Gadgets 1 & 2 can potentially remain powered-on for indefinite periods of time (seconds, minutes, technically even hours, etc).
Now, for my actual questions
As you can see, I am unsure as to what components I should insert into the two (-) return paths after the optoisolator. Do I need to insert anything? What happens if only gadget 1 is powered-on and current flows to both gadget 1 and gadget 2's negative terminals?
If that is an issue what components do I need to add at the (-) return paths? Simple diodes don't work because you know which battery the power is coming from at any given time. Is there a particular component that people use to solve this issue?
*Extra question:
Would a simple NPN transistor work as a replacement for the optocoupler? If I connect gadget 1 & 2's positive paths to the base of a NPN transistor it should allow gadget 3's current to pass across the transistor's collector and emitter. However, what happens to the the current applied to the base? I don't want that extra current flowing through the transistor into Gadget 3's sub-circuit.. do transistors allow the base current to flow out the emitter or what happens to it?
