Circuit Design Library

During the 1990's to today AirBorn Electronics produced custom electronics. The designs on this page are early examples of our work, and are free to copy or use. Besides the fact WE still use the circuits, we leave this page here as one example of an early, really quite beautiful, style of rendering html.

You are welcome to use any of this material for reference or experimentation - and if you manage to then go on and make a commercial success by using it, good for you. No warranties are expressed or implied.

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HSETI1 - AT89C2051 project PCB

8 High current drive LED strings
Speaker drive output
Photo sensor input, adjustable sensitivity
Unused lines (incl. serial port) available on pads
Battery Powered

The small HSETI1 PCB is specifically copyright free. Individual diagrams are available on the links below, and the complete HSETI PCB design is also online.

Australian Customers: You can get faster downloads on our AUSTRALIAN MIRROR

485hub1 - RS485 Active Hub (5 port)

5 signal buffered party line data ports
Industrial grade pluggable wiring block connectors
Handles all NRZ protocols (Protocol independent)
Plugpack or 12v supply

Serial to Parallel converter

9600 Baud RS232 input - Alterable in software 1200 - 57,600 Baud
Centronics style parallel output - Busy, 8 data lines, strobe
Bidirectional - Parallel data tx'ed back out serial port when switch/signal asserted
This PCB is the prototype board supplied with the PG2051 programmer.

Explanation and features
Evaluation kit circuit diagram - used as basis for the serial to parallel converter
Serial to Parallel converter firmware - written in 8051 assembler (copyright free)
tasm32.zip (or original from telemark) - assembler to compile the firmware

RFkey1 - RF Key (Interrogative type)

Challenge response authentication over 300MHz link
Single chip microprocessor controlled
Battery powered, status LED
90 x 50 x 23mm prototype

Sonar1 - Buddy line Sonar - direction finder

Underwater recreational diving direction finder
Ultrasonic Tx/Rx
Magnetic coupled switches
Backlit LCD display
12v Gel cell powered

RCM710 Electronic Scales

Electronic scales with Fluro display and membrane Keyboard
System capable, with RS232 interface
Batching output control capability

This larger project has several pages of circuit diagram

Keyboard section for electronic scale project

A A full, complete technical documentation manual for the scale project is also available, making it the most complete example of our work on presentation here.

ICL 232 chip - RS232 To TTL Level translator PCB

Dual RS232 to TTL Interface - two DB9 connectors
DB9's are handshake looped
6 pin SIP TTL Interface connector
Suitable for 8052MCRO PCB

AirBorn Electronics - microprocessor electronic design and manufacture - Design step by step

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