Code Practice Oscillator Key Circuit
PARTS LIST | |
R1 | 10kΩ |
R2 | 100Ω |
R3 | 100Ω |
R4 | 18kΩ |
R5 | 180kΩ |
C1 | 0.047µF |
C2 | 0.047µF |
C3 | 0.0022µF |
Q1 | 2N4871 |
Q2 | BC109 |
SW1 | Key Switch |
LS1 | 4Ω-8Ω speaker |
Q1, a unijunction transistor, generates a sawtooth of about 1.5kHz to 2kHz, depending on C1 and R1. Q2 acts as a speaker driver. A 9V battery is used, and the keying is done by keying the supply line.

2N4871 PN UNIJUNCTION TRANSISTOR
Please send your ideas, which are very important for our success…
Leave a Reply