I was asked by the MDRC committee of the day if I would like to take on the role as Electronic components and project officer, I didn`t see any problem with this and agreed. After being elected into the position I soon found out that a little more time would be required than I expected, most of which was spent answering m
Click here to download the full size of the above Circuit.
ail. One item that kept popping up was a couple of small problems with a project released prior to my association with the club, being the 1988 Mark 4 Power Supply Project. The following is the upgrade notes to rid the problems without a total rehash. For over 20 years now the Moorabbin and District Radio Club has supplied kits to the amateur fraternity. Our current mark 4 has been quite popular since its introduction in 1988. However, recent constructor feedback has necessitated the need for an upgrade. The regulator circuit of the mark 4 employs a linear design based on the long standing industry standard "723" regulator from Fairchild (tm). Current trends obviously lean towards Switch Mode designs as they are inherently more efficient, physically smaller and cheaper to produce. However many switch mode designs are often noisy, even when displaying good regulation characteristics and it is for this reason that we have maintained a linear design. The Mark 4 as with earlier MDRC supplies is equipped with over Volts protection. This prevents the unregulated 24 to 28 Volts DC from causing damage to your equipment in the event of a regulator failure. It is with this part of the power supply circuit that constructors are experiencing problems, the symptoms are as follows. The over volts protection circuit is a simple resistor, zener diode arrangement with transistor switching. In the event of a output of more than 15 volts the...
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.....
characters left: