In this tutorial we will see how to make a water level meter circuit with the built-in uln2803.The printed circuit is included, the operation of the same will be explained, as well as we will see the characteristics.It will explain how to assemble the zonda, to measure the water level in a water tank.This is the first video of two, in the second video, we will bring the measurement data to the internet, with some cloud service.The ULN2803 integrated circuit is used as a power interface for circuits with CMOS and TTL technology. This integrated has inside 8 NPN transistors in Darlington configuration with protective diodes, to be able to control motors, inductive loads,relays, and more. Each output can control up to 500 mA so you can control different types of loads. Outputs can be connected in parallel when higher loads need to be handled, however it is advisable not to exceed the total power of the circuit.Features:8 NPN Darlington transistors in common emitter8 reverse voltage suppression diodes to handle inductive loads, with common cathode connectionsOutputs of 0.5A (500mA) max.Transistors can be connected in parallel for greater current capacityOutput support voltage: -0.5V to 50VMax power: 1.47 WInput resistance to the base: 2.7kInput voltage: -0.5V to 30V5V TTL and CMOS compatible inputsEncapsulated: DIP 18-pinApplications:Command of relays, lamps, or displays (LED or gas discharge), etc.Logical buffersLine driversAmong other applicationsOperationTo activate each output of this integrated circuit, the water must not be pure, in its contents it must have some salts, which help to conduct electricity, that when reaching each of the levels in the container, closes the electrical circuit of the ulN2803 inputs, which detect the high voltage level and turns on the LED corresponding to each output. At each output we can connect for example a relay, a buzzer and even the pump of an engine to refill a water tank, if necessary, up to a certain level and disconnect the water pump when reaching the desired limit.The following figure shows the ULN2803 pinout. Comes with 8 input pins and 8 output pins.The following figure shows the logical diagram of ULN2803. It is a visual representation and arrangement of how diodes are connected in the component.The following figure shows the schematic diagram for each pair of Darlington.Materials8 resistors of a 1K 8 10K resistorsMale pinsAn integrated circuit uln2803apgAn 18-pin socketA printed circuitDiagram

The original ISPINDEL PCB is CHERRYPHILIPYou can find instructions, video tutorials on youtube (key search iSpindel). THANKS ALL USERS for that.The cherryphilip 4.1 PCB for the iSpindel, few minor improvements introducing on this version. Here main features:On the front , I moved of few mm the thermal sensor device outside battery area. To avoid possible short circuit due to pins that could touch the body of battery or ti have fake measurements.On the bottom edge there is a change as well. I indroduced a specific form just to touch the bottom petling.During the design i used a Sansung 30Q battery with 48gr weitght incorporates a fixeble battery holder allowing you to have your iSpindel to 25° degrees in pure water. However, there are some battery with different weights that can changes the final balance. No worries, iSpindel works fine with balance between 20° to 30°Sincerely,cherryphilip

1. Support I2S-24/LJ-24/RJ-16/RJ-18 output format2. Input sampling rate supports 32~192KHZ3. The output signal level is 3.3V4. Switch selects coaxial or optical fiber as input sourceMore Details: http://audiohobby.ru/articles/prostoi-interfeisnyi-modul-spdif-to-i2s-dlja-cap-na-ak4113.htmlhttp://audiohobby.ru/articles/prostoi-interfeisnyi-modul-spdif-to-i2s-dlja-cap-na-ak4113.html

Amiga 500+ RAM expansion board for internale use (trapdoor). It will add 1MB chip RAM to the default system RAM.

This small breakout board has been designed to make installing Atari VBXE easier (using DIN13 video output).Has pads on both sides of PCB so allows for some flexibility when installing.

"Fake" Elgato Eve Weather (2021) Apple HomeKit compatible temperature, pressure, humidity sensor using BME280 and OLED ScreenPick and Place file for odering: https://github.com/HomeKidd/ESP8266-HomeKit-New-Eve-Weather/raw/main/images/PickAndPlace_HomeKid_Weather_v1.0.0_2021-04-08.csvFeatures:Temperature Sensor accessoryHumidity Sensor accessoryBarometric Sensor accessory (requires Eve app)Characteristic for detecting your altitude (used for proper barometric calculation, requires Eve app)12 hour Weather Forecast (requires Eve app)OLED screen with weather iconsSwitching Temperature Display Units between Celsius and Fahrenheit (requires Eve app)Downloadable User Manual (requires Eve app)Reset buttonPart Links:ESP12F/E (Bosch BME280 I2C bus sensor1.3” SSD1306 OLED displaySMD 0805 resistors (10K, 5.1K)SMD 0805 capacitors (10uF, 100nF)AMS1117-3.34.5x4.5 buttonUSB Type-C2.54mm 90 degree female header2.54mm header (optional)

My first PCB project for LED stairs

https://github.com/gausie/rpi-rgb-led-matrix/tree/p10transformer

PCB antenna on 5288.29MHz and 5807.81MHz.

In the video I show each procedure step by step

So I was needed to control almost 200+ relays using one microcontroller and during research I found out that best way to do it is by using a GPIO Expander module but I wanted to have some simpler solution which should be both small and compact. Now if you worked with addressable RGB LEDs or neopixels you already know that we can control lots of such LEDs by just using one output pin. There is a chip inside each of the LEDs which can control 3 outputs, Red, Green and Blue LED in this case. It reads the data coming from the microcontroller, set it's outputs according to the given instructions and pass the rest of the code to the next IC. This way we can daisy chained as many of them as we want. I just wanted to impliment the same principle for any output devices in general, such as relays, to control even bigger loads.

An important circuit to protect:1- Protect from over and low voltage that damage divice, and can set the high volt by R17 and low volt by R18. to have safe range for your device.2- Protect from fast volt Fluctuation by using timer feature to protect sensitive devices.3- Can set circuit using a variable power supply and move R17 until the red LED lights up for highest voltage, and move R18 until the yellow LED lights up to set the low volt, and the circuit will make device off at these values, and play between them.4- Can set the Time of timer by R7 from seconds to several minutes. To protect from fast voltage fluctuations and have to be a long time for the sensitive devices.5-To operate the circuit 12 volts to 30 volts 200mA,but the input volt for load is Optional from 1 to 60 volt and output is 1 to 60 volt 15A.6- The red-yellow- blue led is off and green is on that means: devices are playing.7- The green-yellow led is off and red-blue is on that means: over volt and devices are off.6- The green-red led is off and yellow-blue is on that means: low volt and devices are off.7- The green-yellow-red led is off and blue is on that means: timer start Counting and devices will play when time up.8- The device can be started directly by pressing a switch to cancel the timer delay time Note : To cancel the delay time, you need to press the switch each time.Note:*The input of the variable voltage and 12v must be from the same power supply(The same GND) *Add a small heat sink for 7809 voltage regulator.

Для работы только с внешним дисплеем по шине i2c не нужно устанавливать следующие элементы: D_LCD1, TR1, R8, Q5, R10, R9, IC3Для работы с установленным дисплеем не обязательны элементы Q5, R10, R9 (если не планируется автоматическое отключение подсветки дисплея), в этом случае перемычка LIGHT должна быть установлена.При питании платы от источника 5 вольт не обязательны элементы: C1, C2, C3, MC7805DT. Так же должна быть установлена перемычка BYPASS. Перемычку вместо диода D1 ставить не рекомендуется, так как диод предназначен для защиты платы от переполюсовки питания.Перемычка SEL устанавливает напряжение коммутации нагрузок (при питании от 5 в источника в любом положении будет 5 вольт). Спикер так же будет запитан этим напряжением.Если не нужны светодиоды для индикации работы насоса и тэнов (все и так имеется на дисплее), можно не впаивать элементы: R5, R6, R7, LED1, LED2, LED3.Определить адреса расширителей портов можно следующим образом:У микросхем с младшим адресом (PCF8574, PCF8574P) адрес вычисляется следующим образом:S 0 1 0 0 A2 A1 A0 - где 0100 базовая часть адреса (в двоичном коде), а A2,A1,A0 состояния на адресных пинах микросхемы (3,2,1 соответственно)Для примера: на схеме установлена IC1 с младшим базовым адресом 0100.Адресные пины микросхемы подтянуты к земле (состояние логического 0)Значит адрес микросхемы в двоичном коде будет 0100 0 0 0, переводим в шестнадцатиричный вид с помощью калькулятора windows в режиме программист. Получаем адрес 0x20Если адресные пины подтянуты к плюсу питания как у IC3 (состояние логической единицы)То адрес будет 0100 1 1 1 - 0x27Для микросхем со старшим адресом (PCF8574A), адрес вычисляется точно так же, за исключением базовой части адреса S 0 1 1 1 A2 A1 A0 она равна 0111Считаем:(0111 0 0 0 - 0x38 для IC1) и (0111 1 1 1 - 0x3F для IC3)Вместо uln2803 теперь можно установить uln2003 сдвинув ее к ключу, и соединив 8-9 и 10-11 выводы.ТОЛЬКО ДЛЯ ЛИЧНОГО ИСПОЛЬЗОВАНИЯ.НЕ ДЛЯ ПРОДАЖИ.

Amplifier Lanzar (mod by Aka Kasyan)300WThe maximum supply voltage 8 Ohm = +/- 65V 4 Ohm = +/- 60V 2 Ohm (bridge 4 Ohm) = +/- 40V Amplification factor 28Imput resistance 27 kOhm?

decided to make me and the boys some keyboards. these boards are feature packed including reversible usb c. first time ever designing a pcb from start to finish. i think it turned out great. best of luck to anyone brave enough to follow in my footsteps. (please note the cover image is of a switch plate for an 80%) the switch plate for this can be found at http://www.keyboard-layout-editor.com/#/ under the default 60% layout.

I made the Amiga Mouse Switch, a device for quickly swapping between a mouse and a second joystick on everyone's favourite Commodore Computer (that isn't the C64). This is a faceplate that goes on top of that device, mainly making it look like a professional looking device without actually buying a 3d printer, testing it out and then buying an even more expensive 3d printer - just to make it look pretty!