Electromechanical to Computer Interface


There often exists many old style electromechanical devices in the research laboratory. This includes devices consisting of relays, motors, solenoids, transformers, vacuum tubes and switches. Often these devices are not well isolated from the AC power source and they always generate a lot of electrical noise. These devices can be stand alone but are most often attached to standard rack mounted systems.

Computer control is the most powerful technique for research today. But computer systems are inheriently low voltage and are very suspectable to electrical noise. Thus putting electromechanical devices under computer control can be particularly challenging.

I build devices that interface the noisy electromechanical environment to modern computer systems. Sometimes rack mounted and other times stand alone my interfaces isolate the sensitive world of computer processing from the noisy world of relays, solenoids and switches. I also create modern electronic replacements for electromechanical devices. These replacements are inherintly less noisy, lower power and directly interface to the computer.



My Electronic Pulse Former device is a good example of an electromechanical interface. It is a direct replacement for the old fashioned relay driven one. It produces an electronic pulse output from an electromechanical input. The device employs electrical and physical isolation of the input using optical-isolators. Electronic output is provided by high power transistors.

This device is particularly useful conditioning noisy key switches or other electromechanical outputs and can provide a constant width pulse to a computer interface.




To simplify interfacing where rack mounted systems already exist I can build my electronic devices to easily attach to them. This maintains the usefulness of older apparatus and helps keep the physical mess in a research laboratory under control.

The computer connection is then made through the existing rack mounted system. Since my devices electrically isolate and condition the electromechanical apparatus there is no chance for damage to the computer system. And data collection can proceed without concern for noise.


With all this attention keeping electrical noise to a minimum it is ironic that I was asked to build a "Noise Generator" to go with Rat operant chambers. To be fair the device generates acoustical white noise and not electrical noise. But it's ironic none the less.

My Noise Generator is a good example of a modern electronic design replacing an old electromechanical-vaccum tube one. It is small, low power, low noise (electrical) and computer controlled. And it replaced a large, power hungry and failing hot box.