LarryD:
But, why not bite the bullet, spend 10 minutes, learn about NPN, PNP, N-Channel and P-Channel, type transistors.
I don't know what gave you the impression I don't know about them: my point was that sometimes at the conceptual stage of sketching out a circuit one might not know nor care that it's a bjt or a mosfet. I have a motor on my bench right now that some time back I ran with a bjt but which I more recently ran with a mosfet; for the purposes of my sketch (which was to measure the rpm via an encoder) that it's a bjt or a mosfet is totally irrelevant.
Of course, at the time of wiring the whole thing up, one uses the correct ancilliary components (resistors of the right spec, in the right place) and checks the transistor can handle the motor.
Conceptually, I simply need an electronic switch, and the goings on inside that switch are of no consequence to me under the circumstances, hence my wondering if there was a symbol for a transistor without worrying about it being a bjt or a mosfet.