Query as to the existence of a component

[LeadStuffer]

Hello.

I'm not great with the hardware side of electronics, and so am not sure as to whether a specific type of component exists or not.

The type of component I'm after is similar to a transistor, in that it would use a base to control a current, however a transistor (as I understand it) is just an on/off switch controlled by the base.
I was wondering if there is a similar component that controls the current through the collector and emitter, so that this current is proportional to the power given to the base.

Does anyone know of such a component, or would I just have to make a new circuit to do something like this?

 

[davenn]

hi ya
welcome to EP

The type of component I'm after is similar to a transistor, in that it would use a base to control a current, however a transistor (as I understand it) is just an on/off switch controlled by the base

your understanding isn't correct
if the transistor is fully turned on or off then it acts like a switch ......
if the voltage / current to the base is varied, then the collector - emitter current is also varied .... hey presto ... an amplifier

 

[LeadStuffer]

Thanks

if the voltage / current to the base is varied, then the collector - emitter current is also varied

Further question; would the voltage(input.base) be proportional to the voltage(output) and the current(input.base) be proportional to the current(output), or would it just go on power (P=VI) and the rest be determined by the resistance of the circuit (V=IR)?

I don't know the components, but i do know the physics

 

[(*steve*)]

Google "transconductance"

 

[LeadStuffer]

Google "transconductance"

Thanks for the tip, looking into it