This circuit was obtained from an American documentation from the 90's. The components can be changed, and a power step can be added for greater sound volume.
This circuit is from an American documentation from the 90's. The SCR can be of any type and the...
The circuit in the figure is suggested by Texas Instruments in its optoelectronics manual and...
This is a general purpose pramplifier launched in Brazil by Philips in the years 70. The BC549 is...