This circuit was suggested by Sprague Electric in an 80's documentation. The circuit uses a tachometric sensor for feedback. The current was not indicated in the original documentation.
IDT ZSSC3230 Capacitive Sensor Signal Conditioner Available from Mouser Electronics stock, this IDT...
This circuit uses only two common transistors and provides good audio power in a speaker. Readers who...
This is the analog part of the previous circuit with the pressure sensor for the altimeter. The...