The goal is to freeze different stages of some fairly quick process (at least when compared to the time resulotion of the human eye). Since I don`t have fancy toys like a high speed film camera, lack of good equipment has to be compensated with a smart setup applying just a an ordinary consumer-type digital camera and some self-made electronics. U
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nfortunately, the camera`s minimum exposure of about 1ms is too long for the purpose and furthermore the delay from pressing the button to actually opening the shutter is around a second - quite long. So, the basic idea is to make the complete room dark, open the shutter of the camera, drop the ball, ignite the photo flash after some time and close the shutter again. This way the real exposure time is given by the duration of the photo flash which was measured by me (using a DSO) to be less than 100us (better than 1/10, 000 second) when set up accrodingly. So, first we need to hold the ball and make sure it falls down each time at the same point, so using one`s own hands is not an option. Instead, since steel balls are magnetic, we built a dropping device made of an induction coil. (In the image on the right, white paper is wrapped around the coil. ) When switching off the current through the coil, the ball drops down. To prevent sparks and high voltage peaks, we were actually using a RC-damped MOSFET-based switch to slowly turn on/off the the current through the coil. Hence, using the switch time as start signal is not precise enough and a self-made light barrier was used. The light barrier consists of a orange LED and a photo diode. In front of the LED, a lens was introduced to focus the light onto the LED. Light interruption by the ball is the start signal. After the start signal, some time passes during which the ball...
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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