TV Pattern Generator Circuit Diagram
This single-IC TV pattern generator is useful for fault finding in TV sets. You can correct the alignment of the timing circuits of the TV set with the help of this circuit. The vertical stripes (bars) produced by the pattern generator on the TV screen help you align the vertical scanning synchronisation circuit of the receiver. To test the TV set, you need to connect the video and audio outputs of the circuit to the respective inputs of the TV set one by one. If the video section of the TV set is working the circuit generates vertical white lines on the TV screen, and if the audio section is working you hear sound from the TV’s speakers. You can also adjust the width of vertical lines. TV Pattern Generator Circuit Diagram The circuit uses hex Schmitt inverter IC CD40106 (IC1). NOT gate N1 generates horizontally synchronised (Hsync) pulses for the PAL video signal. Presets VR1 and VR2 are used to control the ‘on’ and ‘off’ time durations of the oscillator, respectively. For PAL, you ne...