Can you share more details about scary doorbell camera stories?3 answers
2024-11-24 16:47
Sure. In one story, a man saw on his doorbell camera that a hand was constantly reaching for the doorknob but there was no body attached. It was so terrifying that he couldn't sleep that night. He thought it might be a technical glitch at first, but after checking the camera settings, everything seemed normal.
Simple Electronic DoorbellMaking a simple electronic doorbell involved the following aspects:
1. ** Elements and Principles **
- The core component was the music integrated circuit, which was a large-scale complementary symmetrical metal-oxygen-semiconductor integrated circuit. It stored music inside, and the contents of the read-only memory determined the music stored. For example, it has external power supply positive and negative pins (DV and Vs), internal oscillation external oscillation resistance pins (osC1, OSC2, some integrate the oscillation component inside the chip and cannot be externally adjusted), trigger (TL, can use high level or positive pulse trigger), music signal output (OUT) and other pins.
- There were also transistors (such as 9013 or 9014) that could amplify the electrical signal output by the integrated circuit to ensure that the speaker emitted a louder sound. The speaker (B) was a sound component, the LED was used for light display, and it flickered with the music. There was also a button switch (SSS) and an AC bypass bypass circuit to prevent the music integrated circuit from being triggered by noise induction.(C, it could also be replaced by a 300g-510g 18W carbon film resistance, or directly connected between the music integrated circuit's voltage and voltage pins).
2. ** Work process **
- Every time the button switch SSS is pressed, the trigger terminal TL of the music integrated circuit A will receive a positive pulse trigger signal. When the music integrated circuit A works, its output terminal OUT will output the stored music electrical signal once. After being amplified by the triode ZT, it will drive the loudspeaker B to sound. At the same time, the light-emitting LED installed on the shell panel will flash with the rhythm of the music.
3. ** Creation process example (Take teaching tasks as an example)**
- First of all, he had to understand the characteristics, working principle, types, and other knowledge of the electronic components of the electronic doorbell.
- Learn how to test electronic doorbell components.
- Confirm the installation plan, such as choosing a suitable location (such as the door frame or the wall, consider the connection and power supply requirements) to install the electronic doorbell host and connect the various components, connect the power supply (you can choose a special transformer or directly connect to the household power supply), commission and test (check whether the ringtone, indicator light, intercom and other functions are working normally after the power is turned on, and if necessary, commission and trouble-shooting), arrange the wires, and finally thoroughly check the appearance, function, and safety of the electronic doorbell.
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Making a homemade doorbell is simpleThere were many ways to make a doorbell, some of which were relatively simple.
One method was to use 9300 music films to make a doorbell. The materials needed were speakers, printed circuit boards, transistors, switches, metal sheets, screws, plastic shells, batteries, 9300 music films, wires, and tools such as a screwdriver, an electric iron, a sharp-nosed pliers, and a tin wire. The production steps were as follows: First, install the battery box, install the plastic shell and put the battery into it; then assemble the switch, using metal sheets, wires, and a small white plastic box to assemble a switch; then insert the triode into the printed circuit board and welding, and cut off the excess pins; install the wires on the printed circuit board, and then welding the switch and the wires on the printed circuit board together; then, the speaker and the wires on the printed circuit board are welding, and the battery box and the wires on the printed circuit board are welding; finally, the shell is sealed.
There was also a method to make a doorbell with a doorbell. The experimental device required a doorbell, a bread board, a button (expansion experiment), and a number of colorful bread boards for rope skipping. Plugging the passive Buzzer into the bread board, connecting the positive pole to pin 8 on the development board, and connecting the negative pole to GND, then uploading the code to the development board. In terms of programming, first set the digital 8 pin that controls the buzzing, set the digital IO-pin mode as the output, and then control the delay of the high and low levels in the loop program to make the buzzing sound at different frequencies. When making a push-button doorbell, you also need to set up input and output pins and other operations. When the button is pressed (high level), the doorbell will emit a specific frequency of sound, otherwise it will not sound.
In addition, old phones could also be modified into doorbell phones. However, the information did not mention the specific production process in detail. It only showed the feasibility of this idea.
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I love it I love it If you go on hiatus, I'll ring your doorbell