I need help to build a simple Voltage activated switch,5 volt dc input,anyone got any simple circuits ?

 

I need help to build a simple Voltage activated switch,5 volt dc input,anyone got any simple circuits ?

This sounds like you are describing a 5 Volt relay. Does not get much simpler than that.

Presumably I am misunderstanding what it is that you want.

 

This sounds like you are describing a 5 Volt relay. Does not get much simpler than that.

Presumably I am misunderstanding what it is that you want.

Ok i have a circuit that is giving me 5 volt output and i need some kind of switch to activate another circuit for when that 5 volts is showing up,sorry i suck at explaining things.

 

Could you maybe post the actual homework question that you were given?

Or describe what the "other circuit" is, and how it is to be "actuated"

Is the input always supplying 5V or 0V, or are you saying that you want the switch to activate only above, say, 4.5V?

Maybe a transistor switch is what you are asking for?

... or maybe an opto-isolator if there must be no interaction between input circuit and output circuit?

So far the 5V relay is still looking pretty good.

 

It really depends on what kind of circuit you want to drive. If it is a digital input, an optocoupler would be a good idea. It has great disturbance rejection. Relays might cause unwanted switch bouning.

If you want to power an entire digital board, or you want to drive analog circuits (motors, power amplifiers etc) a relay with the adequate current capacity would be better suited in my opinion.