A power supply circuit to bring 24VAC down to 5VDC. I have an L7805CV, but rectified (a bridge) and smoothed (a 33 F electrolytic), the input is still $40V_{peak}$, which is more than the max input voltage the regulator can take. Looking at the regulator`s datasheet, it suggests the following `High Input Voltage Circuit`, which notes `$V_{in} = V_i - (V_Z + V_{BE})$`, but doesn`t offer any guidance on Q1 or R1: because
Click here to download the full size of the above Circuit.
when i orient it as indicated, with the striped cathode end toward $V_i$, the voltage at $V_{in}$ is the full 40V minus approx. 2 diode-drops and the voltage across the zener is only about 0. 7V. (Note that at this point, i have a 33k resistor to ground in place of the 7805 so i don`t damage it until i get the limiter right. ) It is possible that it`s really just marked wrong I made some mistakes wiring it up the first time and something let out a wisp of smoke before i cut the power, but i wasn`t able to figure out which component, and everything i`ve been able to test measures okay. Could overcurrent have somehow magically reversed this diode
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.....
characters left: