Ultra Sonic Radar

Hello all, new to this forum and a pleasure to be a member!
How difficult would modifying the output of radar circuit to my PC instead of just an audible alarm??

Welcome, mrbreeze66!

The TR1 and 2 (darlington pair) output circuit could be used to trigger an oscillator, whose output could be fed into the microphone jack of the PC.

Looks like a motion detector rather than radar, you could however with the aid of a pullup resistor connect the output on terminal 9 to one of the handshake signals on the rs232 serial port of a pc, a vb program can be written to pick it up.

The circuit is not radar (radar works with high frequency radio signals). Instead it is a form of sonar (using ultrasonic sound signals).
It does not detect distance.

EDIT: I agree it is a simple motion detector with a very short range.
It is a kit made in Greece so maybe there is a translation problem with its function as a "radar" unit.

If you have an older style computer with a Parallel port or a Game port installed on it, you can simply connect the output of the ultrasonic alarm to this port (use of an optoisolator is suggested). If your computer doesn't have these legacy ports available and only has USB, I would suggest the K8055 USB interface kit.
This kit comes with all hardware and software necessary to interface multiple Digital and Analog Inputs and Outputs to your PC using a USB port.