This simple injector and signal follower employs a high impedance headset. Transistors can be of general use. The circuit is from old American documentation.
Found in an RF Design from the 90's this circuit is intended for crystals of less than 1 MHz....
This 1968 Mullard circuit detects fire by smoke using LDR-type sensors. The circuit makes use of...
This circuit can memorize an input signal as a charge on the capacitor. The memorization time...