2 Transistor LED Flasher Circuit
R1 = 10M ohm
R2 = 1K – 100K ohm
R3 = 470 ohm
C1 = 0.47uF – 10uF/25V
D1 = 1N914
Q1 = 2N3904
Q2 = 2N3906
Led = High Brightness Red LED
Component values aren’t significant, attempt anything else first from the junkbox.Obviously, the 470 ohm resistor (R3) determines the LED’s brightness and limits the current flow to around 20mA. R3 value of 390 ohm can also be implemented as a save value.
This schematic diagram come from circuit: LED Flasher 2-Transistors
Go to that page to read the explanation about above circuit design.
In the electrical sector, a schematic diagram is usually used to describe the design or model of equipment. Schematic diagrams are usually utilized for the maintenance and repair of electronic and electromechanical devices / units. Original schematics were made by hand, using standardized templates or pre-printed adhesive symbols, but nowadays Electrical CAD computer software is often used.
In electronic design automation, until the 1980s schematics were virtually the only formal representation for circuits. More lately, using the progress of computer system technology, other representations were introduced and specialized computer languages were developed, because with the explosive development of the complexity of electronic circuits, classic schematics are getting less practical. As an example, hardware description languages are indispensable for contemporary digital circuit design.