The simple relay adder was built using free NOS relays sometime in 2005, but my goal was to someday build a more elaborate one that could run programs but notfill up a room like the early computers. Harry Porter built an incredible 415-relay computer which can be seen at this page: I never thought I`d fully understand how his computer worked, let
Click here to download the full size of the above Circuit.
alone build one. Finally in spring 2007, I gained more understanding of computer systems from a course in college then joked to a friend about using the x86 instruction set for a relay computer to boot up Windows, which would`ve taken several hundred years on a relay computer running on a 50Hz clock. And so the inspiration began. (note: if you want to skip the hardware details of the computer, the pictures and videos are at the end of this page). Seriously, the x86 instruction set is insanely large for a simple relay computer so I created my own instruction set. I looked at Harry Porter`s relay computer design for inspiration and ideas for the hardware. But first, the computer cannot exist without the actual relays. After searching several online electronics suppliers for relays, the lowest price I could find was at $1 per relay so a computer using 200+ relays can become rather expensive. So ebay was the next option and after patiently watching several auctions, a lot of 168 SPDT relays came up and I nabbed it for about $25. A few weeks later, another lot of 100 4PDT relays came up and I won it for about $14. Including shipping costs, the total cost for the 268 relays I purchased from ebay was about $60. So, 268 relays became my limit for the computer design. Obviously, I did not try to copy Harry Porter`s relay computer because it called for 400+ relays, but I borrowed many ideas from his design so I wouldn`t have to...
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
Many times for various reasons we forget or can not water the plants that we have in our homes. And many humidity sensors units just notify us with a beeping sound or with a flashing light, that the pot needs watering. But what if we are away from home? This....
The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
The sub-harmonic bass generator is a sound producing unit for guitars. The sound it produces looks very much like that of the bass guitar. The octave generator is sometimes quite unusual since it does not produce any of the usual ways of coloring the sound,....
In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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