What's the circuit diagram symbol for a variable reluctance sensor transducer?

Question

I know I've seen the symbol before, it's something like a circle with an open triangle facing in the direction of current flow with a line through the middle. I'm specifically thinking of the transducers in electric guitar pickups. I've seen the symbol before but now I can't find it.

Answer 1

From Graphic Symbols for Electrical and Electronics Diagrams

2.11 Transducer

Accelerometer

Motional Pickup Transducer

Use only if a more specific symbol is not applicable, e.g., tachometer generator, microphone, motor, loudspeaker, etc.

2.11.1 General, electrical output

Answer 2

Here's the graphic symbol for a variable reluctance speed sensor.