The thyristor fired coilgun is a common variant, due mainly to their high voltage and pulsed current capabilities. A diagram of the system that was designed for these experiments is given in fig 1. The thyristor is an International Rectifier device, part number 50RIA100 (50 A / 1000 V). The pulsed current capability is 1200 A for a half-sine pulse
Click here to download the full size of the above Circuit.
of 10 ms. This series of experiments investigates the effect of charging voltage and launch delta on the projectile velocity and coilgun efficiency. The value of capacitance that can be effectively employed in this type of coilgun is limited due to the fact that the thyristor cannot be turned off once it has begun to conduct current. This requires that the current pulse be of similar duration to the projectile transit time, otherwise suckback will vastly reduce the muzzle velocity. In view of this only the 13, 600 uF and 33, 000 uF capacitors are used. The current sensor was placed in the capacitor ground return path to monitor the capacitor discharge, or in the coil current path to record the full coil current pulse. Placing the sensor in the coil current path means that the measuring equipment (PC `scope and laptop) floats up to some arbitrary voltage since no part of the system is grounded to the earth potential. The charging voltage was limited to 80 V for these measurements. Two switches were considered for commutating the trigger pulse; a mercury-wetted relay and a microswitch. Unlike most mechanical contact switches, the mercury-wetted relay doesn`t exhibit any contact bounce, so the gate current will be maintained without interruption during the critical turn on phase. Figure 2 shows the rising edge of the trigger pulse. Fig 3 shows the initial part of the trigger pulse voltage that is applied to the gate resistor,...
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: