Posted on Aug 17, 2012

Tum on a game, computer, videodisc player, or whatever, and its output takes priority over the antenna-derived signal-the antenna is disconnected and the alternate source is fed to the monitor. When the alternate video source is no longer detected, the switch automatically reconnects the antenna. When the rf carrier is detected, a high logic output appears at pin 15 of U1-squelch status. The signal is then buffered to VMOS FET Ql. This FET can drive CMOS inverter/buffer U2, can be an open-drain output to drive a relay, or can convert to a 5 V logic level.

Click here to download the full size of the above Circuit.

When pin 15 of U1 becomes high, Q1 turns on, pulling pin 11 of U2e low; in tum, pin 12 becomes high. The olitput of U2e is fed to U2f, forcing its output, at pin 15, low. When the signal at U2 pin12 is high, in is biased on, allowing the signal at]3 to flow through C14, D1, and out to ]2 through C13. When the signal at ]3 is removed, U1 pin 15 decreases. That decrease causes U2 pin 12 to decrease and U2 pin 15 to increase. When the signal at U2 pin 15 is high, it biases D2 on, allowing the signals at Jl to flow through Cl2, D2, and out to ]2 through Cl3.

Leave Comment

characters left:

New Circuits



Popular Circuits

Motor speed control
lie detector circuit diagram
minimal arduino with atmega8
light dependent blinker using ldr and cd4093
1kH Synthetic Inductor
Nostalgic Crystal Radios
interfacing rs 232 with spartan 6 fpga
Frequency meter with 10Hz to 2MHz
INA331 332 configured to directly drive the capacitive input A D converter circuit
Having a broadband 50MHz-3dB 20dB compression characteristics of broadband amplifier ALC