The back EMF voltage spikes produced by stepper motors (particularly higher voltage motors) can damage your PC`s printer port if connections are made incorrectly, flyback diodes are absent or connected in reverse, etc. The safest options are opto-isolated or buffered/inverted circuits. For extra peace of mind it is recommended to rather buy a sepa
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rate I/O card to use instead, if your PC`s printer port is motherboard-based. Although this is very similar to Mel Bartel`s circuit, it is not an exact copy. Two main differences exist: By some strange coincidence, I just happen to choose the reverse motor order to Mel. I also did not implement the inverter/buffer stage - I am driving the transistors directly from the printer port. A minor detail is that I seem to have chosen slightly higher rated components which could make a direct copy of my implementation slightly more expensive. Since my beta tester, Greg Roberts built a standard Bartel`s system, the CoSaTrak software was made compatible with both systems. This means that anyone with an existing Bartel`s motorized mount can start tracking satellites straight away! Just before rushing out to witness your first high powered satellite pass, remember that the gear reductions for your astronomical requirements are quite different from the ratios needed for satellite tracking because of the different speeds involved. Also, since I am ten years behind Mel in the development of the software, I cannot achieve the motor speeds he does with microstepping, overvoltage, etc. You will thus find that your astronomically geared mount will have quite a low limit for higher elevation passes around culmination because of the fast azimuth swings required. Satellite imaging (as against satellite tracking) has not yet been tried with our...
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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