This is the built servo amplifier and circuit diagram. This is a simple and ordinary op-amp circuit, there is nothing difficult. However it has power amplifier and small signal amplifier on the board together. You have to pay attention to unintentional coupling on board design otherwise you will be afflicted with oscillation, distortion or instability, and the servo gain will be limited. Currently the PD circuit is a little affected by power amplifier, it may be better to move it on the galvo like existing galvos. The servo amplifier requires a dual output power supply of ±20 volts. It is generated with a simple DC-DC converter powered from a single +12 volts DC supply. It is not that must be regulated, a traditional transformer-bridge-capacitor type power supply will also work well. This is a wave form which is a step response of the servo amplifier. It must be current controlled however the output voltage is saturating due to coil inductance. The supply voltage should be high as possible to minimize this effect. The voltage dip at high output current also be found. It is due to a current limiting of the LM675, a high power opamp, such as LM12, might be better than LM675. However such the strong opamp can burn the galvo coil with over load or oscillation so that any thermal protection will be needed to the galvo.
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The laser controller must generate two vector signals (±1V analog) for galvos and a blanking signal (TTL) to modulate laser output, al least. These signals will able to be generated by any microcontroller board found in junk box or a simple D/A adapter attached to PC's parallel port. In this project, I designed and built a new controller board to minimize the board size. Figure 7 shows the block diagram for the controller board, and the circuit diagram is available in tech notes. The controller only generates vector data with stored frame and there is no more control. It will not needed to explain each function of the controller board and its firmware because you must have a skill to design a laser display controller if you are going to build galvos. Because the graphic data used in laser projector is vector based, not rastar based, generic graphic tools cannot be used to create frame data. Any vector based graphic tool is needed to create vector frames. There are some laser creation tools specified for vector graphics, but they are too expensive for hobby use or temporary project, so I developed a simple vector tracing tool. It handles the frame files in generic csv format because I also wish to use it for any other purpose :-). This is a freeware and is available in tech notes. A script to convert ild frame file into csv file is included too.
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....
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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....
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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....
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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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