Transformers made for powering large neon signs are inexpensive and very reliable. Most commonly, the secondary is center-tapped, which prevents the use of its full peak-to-peak output in applications where one of the terminals needs to be grounded. In the power supply described in this post, I took out the high-voltage transformer out of its metal
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lic enclosure to isolate the center tap from ground. This requires very careful application of a thick insulated layer to the transformer. I used a full can of Shellac to patiently coat and re-coat the transformer. I built a thick Delrin insulating bracket for the modifiedtransformer, and placed it inside a grounded metallic enclosure. I wired it using high-voltage cable that is further insulated by thick silicone tubing. Iliberally use high-voltage putty (GC ELECTRONICS # 10-8882) for insulation. I purchased the high-voltage connectors at Surplus Sales of Nebraska. To obtain a variable AC output, I use a 500 W variac. It must be remembered that neon-tube transformers are commonly designed to first produce a voltage spike to start discharge in the gas, and then enter constant-current mode. As such, the voltage will vary quite a bit depending on the load. A one-to-one voltagerelationship between the variac`s output (the input to the neon transformer) and the neon transformer`s output is only possible for very light loads. Floating DC output is generated by full-wave rectification and filtering of the neon transformer`s output. I used eight NTE542 high voltage diodes (commonly used in small microwave ovens) to build a full-wave-bridge rectifier as shown in the schematic diagram above. Twenty 0. 01 uF @ 10 kV capacitors are used to filter the rectified voltage. I used asurplus panel meter (labeled in kV, probably from an X-ray...
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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