Integrator with JFET (CB6229E)

This circuit was found in an 80s National Semiconductor documentation. The configuration holds true for modern JFETs.

LM3914 expanded scale (CB25110E)
The figure shows how to use the LM3914 bargraph with expanded scale. The circuit has two...
Single Channel Remote Control Receiver (CB18528E)
This receiver activates a relay from signals emitted by a 27 MHz modulated transmitter as...
Time relay (CB22074E)
The transistor in this circuit can be replaced with any general-purpose equivalent. The time...