Ultrasonic Parking Sonar by 40106

Feautures:

* automatic switch on on rear gear
* led-bargraph display
* audible bleep on last led
* “good old” design style, no microcontrollers!

This was one of my first designs: it is an ultrasonic parking sonar.
Based on an ultrasonic amplifier from an article seen on a 1982 magazine, it was once installed on the rear bumper of my Volvo Station Wagon. It served very well for many years. Connecting it to the reverse gear lights, it switches on automatically and shows you the distance to the nearest obstacle (according to his beam) on a led scale. When the last led lights, a buzzer is also activated telling you to stop immediately.sonar.jpg (2787 byte)

It works on the sonar principle, sending an ultrasound burst and listening for first echo. The burst generated by the oscillator built around U4D (you must set the frequency using TR2 to have 40 kHz or the maximum sensitivity), U4E buffers the output and U4F boost the signal doubling the voltage span across the TX piezo transducer .

A new burst is generated each time the decade counter (4017 in the circuit diagram) is in its reset state, that is output 0 is selected. The other outputs (1 to 9) are scanned sequentially following burst generation, until an echo strikes back the RX receiver. It is then amplified by the transistor input stage, triggering the monostable built around U4A – U4B. The monostable stops temporarly the scanning, and a led corresponding to the obstacle distance appears as continuously lit. The buzzer bleeps when the first led (minimum distance) il lit.

Read More Source: http://www.uashem.com/pageid-419.html

Ultrasonic Parking Sonar by 4017
It works on the sonar principle, sending an ultrasound burst and listening for first echo. The burst generated by the oscillator built around U4D (you must set the frequency using TR2 to have 40 kHz or the maximum sensitivity), U4E buffers the output and U4F boost the signal doubling the voltage ...
Ultrasonic Pest Repeller circuit
It is well know that pests like rats, mice etc are repelled by ultrasonic frequency in the range of 30 kHz to 50 kHz. Human beings can’t hear these high-frequency sounds. Unfortunately, all pests do not react at the same ultrasonic frequency. While some pests get repelled at 35 kHz, some others ...
Ultrasonic Range Meter by PIC16F873
This circuit is measuring the range to an object by using ultrasonic transmitter and ultrasonic receiver. The distance is calculated by PIC microprocessor and is displayed on the three digit 7-segment LED display. Source:http://www.hobby-elec.org/e_pic6_6.htm Thank you. Related Links ...
One-IC two-tones Siren with IC 4093
Double-tone Police sound Single-tone old ambulance sound This circuit is intended for children fun, and can be installed on bicycles, battery powered cars and motorcycles, but also on models and various games and toys. With SW1 positioned as shown in the circuit diagram, the typical dual-tone ...
Home burglar alarm with timer delay using one IC 556
This circuit uses IC 556 which have timer 2 the group in one. First group is moto stable and second group does in front is in a state of a signal goes out work to is unfinished although signal. From detect disappear already. But output a pin 9 still have voltage the tall when enc ...