This interesting circuit for SMD assembly appeared in the November 1987 issue of Radio Electronics magazine. The phonons are generated by selected resistors that are fitted to the assembly.
This high input impedance circuit makes use of two operational ones that are still common. The...
This circuit is suggested by Motorola and consists of a voltage reference based on an MC1403. The...
The output voltage is adjusted by the trimpot. The power transistor mist be mounted on a heatsink. The 3.9...