The 5 volt microcontroller interfaces to the RS-232 serial connector and the USB-B connector. It is also responsible for talking to the checker, controlling the status LED`s and setting the voltage for the LOW voltaage microcontroller. The low voltage microcontroller is run at the voltage level appropriate for programming the device to be programm
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ed. It has direct control over a 24V DAC and a 8V DAC. The customization plug is just a large number of female pins for routing power and signals to the 40-pin ZIF socket. One half of the customization plug is hooked to the low voltage microcontroller. The power supply uses a Underwriters Labratory ® approved "wall wart" to provide 24VDC of power. This means that the base board does not have any 110 AC or such voltages running around on it. The power comes in on either N1 (on board) or N3 (off board). The power switch can either be on board at SW1 or off board as SW2 through connector N2. A resettable polyswitch fuse is used to deal with short circuits at F1. D1 is a shorting diode that should trigger F1 if somehow a VAC power source gets plugged into N1 or N3. The rest of the power supply a series of inexpensive linear voltage regulators, VR1-VR5, that step the voltage from 24 volts, to 18 volts, to 12 volts, to 8 volts and finally to 5 volts. All of these supplies are used elsewhere on the board except the 18 volt one, which is used to keep the 24 volt regulator, VR1, from disapating too much heat. The capacitors are tantalum for their low series resistance. This design will not win any energy conservation awards, but since the EMPD3 should spend 99% of its time turned off, there should be no real complaints. Finally, green LED D2 lights up to indicate that the device is turned on. The EMDP4 is a board that uses standard...
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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