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  1. Today
  2. Hello, You could use a rs232 to ttl converter that you could connect to an Arduino microprocessor, You can get the converter for 1$, Arduino from 10$ to 30$ depending on the quality you want. Also you need a power supply about 10$ and a relay about 5$, Plus connectors. see: https://daverobertson63.wordpress.com/2013/06/02/serial-port-mini-rs232-to-ttl-converter-adaptor-module-board-max3232-with-arduino/ Many of us can help you with the software. I just got a large memory Arduino for 10$ that I am using for a talking weather station.
  3. Yesterday
  4. I currently volunteer at a cycling facility with timing system that currently relies on a (12V dc 20mA) normally open tapeswitch being activated by the wheel passing over the tape. The tape switch plugs into the timing system via two 4mm banana switches (sockets) Due to the time and expense involved in laying the tapes down and removing them, hopefully undamaged, the hope is to replace the tapeswitch with our own transponder / loop system which has a decoder with an RS232 output (Rx, Tx and GND). Is there a device that would convert the RS232 signal to analogue to provide an analogue signal to mimic the impulse signal of the tapeswitch. Or at least activate a relay that would mimic the tape switch? We cannot break into the existing system so need a solution that interfaces with the RS232 output of the decoder and the 2 x 4mm banana switches on the venue’s timing system Grateful for any advice kennys
  5. Is it so old that it has one of those old glass vacuum tube thingies?
  6. Throw your task, an electrical circuit on the contacts, I will help you!
  7. Last week
  8. Your circuit is basically incorrect. The DIAC , labelled TRIAC1, would never carry the load in that type of circuit! Only the gate current for the TRIAC. see the circuit at: https://www.electronicshub.org/simple-fan-regulator-circuit/ for example. Good luck.
  9. Hi, As noted in the subject, I have a problem with building of the voltage controlled current source with obligatory grounded load. The input control voltage is in the range from 0 to 5 V, the output voltage is up to 20 V and output current on the load up to 150 mA. The load is some semiconductor device( or material), the (light-emitting)diode for example. Other very important requirements are that the load must be grounded, the control voltage on input and the voltages on the output should be measured with respect to the one common point(ground). I have already used the modified Howland current pump. The scheme is quite good for output current of 25 mA, but the suitable heat sink was required to protect the OpAmp. Also I have used the unipolar voltage supply of the OpAmp to obtain the 20 V of output. The another benefit of this scheme is that the output current does not depend on the load resistance. How to modify the Howland current pump with the grounded load for output current up to about 200 mA (150 required with about 10 -40 mA in reserve)? I have found the example of such modification in the Ref. https://www.edn.com/design/analog/4412375/Choose-resistors-to-minimize-errors-in-grounded-load-current-source. The Howland current pump based, with n-channel FET switch. Fig from Ref. https://m.eet.com/media/1181840/f1x600.jpg I have tried this scheme with OpAmp LM324 and FET IRLB8743, using resistors R1=R2=R3=100 kOhm, R4=104 kOhm, and obtain the output current up to 200 mA by varying of R5 (pot of 5 kOhm) controlling resistor. But as I found from the circuit calculations, presented in the Ref, the output current is dependent on the load resistance. Hence, this current source is quite bad. It is possible to improve the scheme to resolve this problem and to obtain voltage controlled current source with grounded load for output current up to about 150-200 mA?
  10. Hi comunity, I'm using a bta41-600B to control a shower (resistive load purely), using an arduino and zero cross detection to control over phase angle, the circuit draws aproximately 38 amps, triac is mouted in a good heatsink, but as when i increase the voltage in the potentiometer, when it draws more than 25 amps for example, the triac start self triggering and doesn't dimmer anymore(the voltage increase at maximum, even removing the gate signal the triac keeps on at full voltage, i've tried using a capacitor and resistor (39R and 100nf) as a snubber but doesn't work, I've changed the triac but It always happen, thanks for any help.
  11. In the field of electrical engineering, a relay is a relay device designed to trip a switch when an error is detected. The first protection relays were electromagnetic devices based on mobile coils in motion to guarantee abnormal operating conditions such as over current, over voltage, inverse flow, over frequency and reduced frequency. The digital protection relays based on microprocessors now emulate the original devices, in addition to providing non-practical protection and non-mechanical monitoring with electromechanical relays. read more at here http:// electrotopic. com/what-is-psm-in-relay/
  12. Wow looks to be good project for the farming industry
  13. AI Smart agriculture control Device Abstract: Agriculture is the broadest economic sector and plays an important role in the overall economic development of a nation. Technological advancements in the arena of agriculture will ascertain to increase the competence of certain farming activities. Smart Farming is a farming management concept using modern technology to increase the quantity and quality of agricultural products. Farmers in the 21st century have access to LoRa, soil scanning, data management, and Internet of Things technologies, web. Our device focuses on the measurement of physical parameters such as soil moisture content, nutrient content, automatic irrigation, pH of the soil and automatic sent notification phone application that plays a vital role in farming activities. Keyword: Agricultural innovation, IoT, LoRa, Power Management, ARM, Data Management Introduction: Smart farming based on IoT technologies will enable growers and farmers to reduce waste and enhance productivity ranging from the quantity of fertilizer utilized to the number of journeys the farm vehicles have made. In IoT-based smart farming, a system is built for monitoring the crop field with the help of sensors (light, humidity, temperature, soil moisture, etc.) and automating the irrigation system. The farmers can monitor the field conditions from anywhere using smart app. IoT-based smart farming device is highly efficient when compared with the conventional approach. The applications of IoT-based smart farming not only target conventional, large farming operations, but could also be new levers to uplift other growing or common trends in agricultural like organic farming, family farming (complex or small spaces, particular cattle and/or cultures, preservation of particular or high quality varieties etc.), and enhance highly transparent farming. Now, let’s discuss the major applications of IoT-based smart farming device that are revolutionizing agriculture. Hardware: Soil Sensor: The Soil Moisture Sensor uses capacitance to measure the water content of soil (by measuring the dielectric permittivity of the soil, which is a function of the water content). Simply insert this rugged sensor into the soil to be tested, and the volumetric water content of the soil is reported in percent. Temperature sensor (DHT 11): Measure the Temperature and humidity Photoresistor (LDR): Check day or night position LoRa ARM development board : This is a low power single board computer inbuild Wi-Fi, LoRa connectivity also has Digital and analog pins. Smart Agriculture Device Features: 1.This device no need external power (inbuild 5-volt Power bank & solar cell), 2. real-time Soil Moisture sensor measure the soil and sent data to the Server, 3.Temperature, photoresistor measure the weather condition. 4. Both way communication (device can send notification & received command from web or app) 5. Dual control (Device ca run manual mode and automatic mode). 6. Dual communication (LoRa and wi-fi mode) System Hardware Implementation: First configure the FreeRTOS on EFB-REV1 board after successful configure of operating system we need configure GPIO library(J-Tag) to access the its GPIO. Install 5-volt solar cell and power bank for powerup the device 24x7. Soil Sensor connected to analog pin of A0, DTH11 connected to A3, Photoresistor connected to A6. Analog sensors measure data and sent via wireless media. EFB_REV1 development come with LoRa, Wi-fi also Bluetooth, for our project we used Wi-Fi and LoRa. For Wi- fi communication need a wifi receiver module which receive and sent sensor data to the cloud server. Another hand implemented the device for loRa communication (data send rang up to 5km), here we need a loRa receiver to receive and sent sensor data to the cloud server. Wi-Fi and LoRa connective protocol of our smart agriculture device uses depend on different location & situation. Firmware & Application software implementation: Application Software: Here we used cloud server to store the data, and help of Rest API sent the command to the device. Device firmware has two measure function (i) Manual mode: In manual mode device will work, user pre set value of the sensor in device using web or smart app. (ii) Automatic Mode: In automatic mode device sent the sensor value to cloud server and machine learning algorithm take decision according the data. Conclusion Thus, the IoT agricultural applications are making it possible for ranchers and farmers to collect meaningful data. Large landowners and small farmers must understand the potential of IoT market for agriculture by installing smart technologies to increase competitiveness and sustainability in their productions. With the population growing rapidly, the demand can be successfully met if the ranchers, as well as small farmers, implement agricultural IoT solutions in a prosperous manner.
  14. Earlier
  15. Those are connector pins, for Canon or Deutsch.
  16. This post is good and informative.
  17. Internet radio is the best option.
  18. After I did not see the board name (usually write the PCB model), I removed the front panel. But obviously this is a super new version of a PCB and there is no information. If the connector ( sck sda rst vcc gnd ) ... I now see that some of the captions are used in the oled displays. And it's actually programmed or connected to a display instead of a 7-segment indicator ?
  19. As only the CPU has access to the flash memory I would think it would not be possible to access the code. If it were on a separate chip you could read it with the right equipment. It may be better to develop your own code rather then try to reverse engineer this device. chip you
  20. Hello guys I have one request. I bought a hot air station .This device - at a low price - where the main role for the job is using a microcontroller HR7P169 There is a connector option on the PCB and I suppose it is for reading and overwriting. After the station for me was 30 euros and the microcontroller for almost 2 euros. What will be needed to try reading the code and having it as a file this device is powered directly to the electrical outlet to the white connector, and when I set the temperature, I see the heater flashing differently according to the temperature and the power of the air jet. When placed, the stand stops heating and only blows while it is needed or if it reaches 100 degrees and shuts down Chips using in this device : Upper left -> Eastsoft HR7P169BFGTF Upper right -> F7103 in the middle on pcb -> LM358 in the below the transformer -> PN8370 Using moc3023 who the control bta12/800A
  21. Zero Multi-Power Supply (Battery supported) https://www.kickstarter.com/projects/349880250/zero-multi-power-supply-battery-supported
  22. I think you'd better ask the manufacture about this information. most electronic products will test this aspect when produce a sample.
  23. Here is another forum topic discussing this power supply. (in Russian) http://forum.cxem.net/index.php?/topic/209045-бп-на-tl081_0-30v-0002-3а-и-его-модификации/ Translated Link: https://translate.google.com/translate?sl=auto&tl=en&u=http%3A%2F%2Fforum.cxem.net%2Findex.php%3F%2Ftopic%2F209045-бп-на-tl081_0-30v-0002-3а-и-его-модификации%2F
  24. If you look around on ebay or amazon.com for "audio amplifier board 5 volts" you may find something that would be helpful. Like: Icstation PM2038 2X5W stero audio amplifier board 5v USB powered adjustable volume. They are quite inexpensive. https://www.amazon.com/PM2038-2X5W-Stereo-Audio-Amplifier/dp/B01NABJTDJ/ref=sr_1_36?crid=2KDQ8EUT857T7&keywords=audio+amplifier+board+5v&qid=1558736268&s=gateway&sprefix=audio+amplifier+board%2Caps%2C184&sr=8-36 Sorry I can not be more helpful.
  25. Most of the spec's for the headphones are absolutely useless. The frequency response spec's do not say plus and minus 30dB which is horrible or plus and minus 2dB which is pretty good. Who cares about the length of the cord and the weight? The important spec for the ear speakers is the impedance that you can measure with a multimeter but you didn't. If the circuit is modern then it uses tiny little parts that are difficult to solder and unsolder.
  26. I can answer the 2nd question for you, as I have 2 3d printers, both having heated beds. The heated beds are required when printing with some kinds of filament, such as ABS plastics. If the bed is not heated to a certain temp n kept at that temp the print adhision may fail totally or even warp your print(s). So the beds will be needed in some cercomstances. Hope this helps. I think as for the voltage, I think most are 12v DC, atleast mine are. Joe
  27. Ok, first I have a set of turtle beach ear force x11 gaming headset with the following specs: Headphones: - 40mm diameter speakers with neodymium magnet - Speaker Frequency Response: 30Hz - 20kHz, >120dB SPL @ 1kHz - Condenser Microphone Frequency Response: 50Hz - 15kHz - Cable length: 16 ft. (4.877m) - Weight: 6.4 oz. (233g) In-Line Amplifier: - Headphone Amplifier: Stereo DC-coupled, 35mW/ch, THD <1%, Frequency Response: DC - 30kHz - Mic mute switch - XBOX controller 2.5mm input jack - Maximum analog input level with volume control on maximum setting: 2Vpp (700mV rms) - 3.5mm plug for mic output - 3.5mm plug for line input - Weight: 1.3 Oz (36g) - USB connector for power (5VDC @ <50mA max) - Dimensions: Height .5in (1.27cm), Width 2in (5.08cm), Depth .75in (1.905cm) My idiot brother got ahold of my headset and not only ripped the wires loose from the controls output wires, but apperently also fried the controller... my question is, can anyone recommend circuitry to fix the mic and speakers?? Don't care about the controller port as I don't game online with xbox anyhow, so I only need the mic and speakers. I looked on project page, but since my knowlage of audio like this is non exhisting. any help is appreciated. Lucky for me the input side of wires is good, so I got a usb for power, mic plug and speaker plug. Meanwhile, going to try and see if I can locate scematics for the contoller. I know I can just buy new set, but I don't have much cash lately, so fixing them better option for me. Thanks. Joe
  28. audioguru

    LED panel .

    Can you provide a link to the ebay ad? Your schematic shows strings of 3 LEDs in series and a tiny resistor is also in series. Your pink and blue lines show that all the strings are in parallel. Since a white LED is about 3.2V to 3.6V then the entire bunch of LEDs uses a 12V supply.
  29. i also have the same problem :/
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