This circuit allows you to simulate an analog telephone line for the repair and testing of devices. The circuit is from 1994 and all the components used are common.
The output transistors can be the TIP41 and the BD135 and BD136 drivers. TR1 can be a BC558 and...
This circuit was found in an English publication in 1986, but it can still be implemented by...
The Texas Instruments TIOS101 is a driver that can be connected to both high and low side sensors...