The idea was that you removed the center page from the magazine and cut it into four pieces to obtain a card that would fit into a filing system. The front side of each card would gave the connections to the IC, while the other side would contain technical details and an application circuit.
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Fig. 1 depicts, as an example, the front- and back-side of the IC-card for the 74141 nixie driver. Intrigued as I was by the mysterious symbols, these cards enabled me to decipher the basic ideas behind digital electronics. And like most things in life, once you have mastered the basics, the rest comes pretty smoothly. For years I was obsessed by the possibilities of these small black building blocks. It soon became my dream to build a digital counter with display. Now you have to remember that in those days something like a seven segment display was something that not that many people, including myself, had seen in real life. So for my birthday I asked a SN7490 decade counter, a SN7447 BCD to seven-segment decoder, and a 3015-F Numitron display. In those days these components were rather expensive! In the same Elektuur magazine from which the Fig. 1 IC-card was taken, I have an advertisement which offered these components. In the table below, you will find the prices of these components as they were then in guilders, but also in the price in Euro now, based on the ratio of the prices of the Elektuur magazine then (fl 1. 95) and now (Euro 6. 85). Even if I am mistaken by a factor of two, than still it was a lot of money. I still remember my mother saying that she had never paid so much money for so little. My grandmother on seeing the goods and hearing the price was, I believe, in shock for days. I still have the Minitron...
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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