Motorola suggests this circuit in an 80's documentation. The circuit uses an inverter to produce a higher voltage for 9 V battery charge from a single cell.
The presented circuit is suggested by Texas Instruments (www.ti.com) in its Application Report...
The purpose of this circuit is to excite a TTL input with lz pulses. The phototransistor can be of...
This circuit uses damped oscillations to test an inductor. It can also be used to find the...