Circuits FAQ

This is the Archive of Electronics & Technologies related Question & Answers. Ask Questions at EE BBS FAQ. To get a project designed by delabs visit Design Service.

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Tuesday, June 02, 2020

RS485 Modbus - Wireless Interface

I am working on alarm systems and would like assistance in designing wireless link for the unit, ie sensors to control panel, control panel to monitoring station.

I noticed most of the circuits available on your sites are FM 88 - 108 MHz, which would definitely cause interference. Can you please assist me with this final part of my system.

mail from RT

i would like to know........... The wireless link distance of Transmitter and receiver. The frequency range you want like FM 'n' MHz Are you aware of the regulations of wireless transmission.

What band is allowed in your country and what distance. what type of data needs to be transmitted. If this is for process control, RF should be avoided if possible. You should use 4-20mA current loops, RS485 or IR optics.

delabs


You can study these pages ...........

Bridging the gap between Modbus/TCP and Foundation Fieldbus

Foundation Fieldbus

Foundation Fieldbus is a power-ful process automation system which offers numerous advan-tages over conventional techno-logies in terms of production quality and serviceability. But migrating to Foundation Fieldbus often entails changing the entire existing control technology - all the way to the managment level.

Modbus Communication Protocol Suite

"The OMWT-XREC-MOD Wireless Transceiver uses an embedded 100-milliwatt frequency hopping wireless modem that provides communication between a local RS-485 network and a remote network of RS-485 connected devices. The OMWT-XREC- MOD will automatically sense the direction of data flow and switch the RS-485 and radio devices accordingly."

with a RS485 and Modbus Network you can do it.

delabs

Thursday, April 09, 2020

Electronics Work Bench

How can I get a software for an electronics work bench for my pc.

mail from EA

I did not understand about the 'electronics work bench' pc based instrument. Try simulation based virtual lab software.

delabs

TINA is a powerful yet affordable circuit simulator for analog spice circuit simulation, digital and mixed circuit simulation


this may be what you want....i am not sure.....have a look. "Tina Pro - The Complete Electronics Lab Edison - Multimedia Lab for Exploring Electronics" ...   also CircuitMaker which you may know.

CircuitMaker Student Edition

Ssimulation program.... helpful for learning about circuits, testing designs or analyses, and even just drawing schematics for reports.

delabs

Monday, April 06, 2020

Cypress PSoC Mixed-Signal Array CY8C27x43

I am building the same using a PSoC( Programmable System on Chip). I will give a tiny snapshot from their site FYI. PSoC Mixed-Signal Array.

I had corresponded with you some time back when you had guided me to making a temperature controller .It was a very nice experience doing the same.

A true system-on-a-chip, PSoC devices are configurable mixed-signal arrays that integrate the microcontroller and related peripheral circuits typically found in an embedded design.

mail from TF

Programmable System-on-Chip - PSoC - CY8C27x43

The PSoC family consists of many Mixed-Signal Array with On-Chip Controller devices. These devices are designed to replace multiple traditional MCU-based system components with one, low cost single-chip programmable device. PSoC devices include configurable blocks of analog and digital logic, as well as programmable interconnects.

PSoC EvalPods

PSoC EvalPods are pods that connect to the ICE In-Circuit Emulator (CY3215-DK kit) to allow debugging capability.

CY3210 - CY8C27x43 PSoC(R) Evaluation Pod (EvalPod)

They can also function as a standalone device without debugging capability. The EvalPod has a 28-pin DIP footprint on the bottom for easy connection to development kits or other hardware.

Saturday, April 04, 2020

Interface 89C52 with 7135

i am interested in doing with 89C52. And now I trying to use AT89C52 and ICL 7135. And I use nterrupt 0 to get BCD data from ICL7135. I send you my program here and expect to get your advice soon.

post by NHT



I have made a circuit for you to study, also some idea about the code. you need to have Adobe Acrobat Reader

You can find it here Microcontroller you can now try to write the code and draw the circuit you need.

AT89C52 Parallel Interface to ICL7135

AT89C52 Parallel Interface to ICL7135

This circuit is an interface between 89C52 of Atmel with 7135 of Intersil.  With This circuit you can read analog data of both polarities you can change the range scale with extra circuits, you can store data on a EEPROM or send them to PC thru RS232 or Comm port.

delabs


Friday, February 21, 2020

What is a Relay - Jim Asks

(A text chat in Google talk long ago from my email records - 2007)

Jim: hello,
delabs: hello

Jim: i have a Small problem,it's about relays.me: would u pls give me an information about relays,pls give different types of relays and their differences.

delabs: for what do you want to use the relay for.

What is a Relay - Jim Asks

Jim: Two door alarm settable for close or open door

delabs: there is a control signal and an output for relay, if you are using just a buzzer for alarm, no relay needed if you want to operate a big hooter or 230V lamp a relay is needed- or even a motor or solenoid to move some thing  Even a Solid State Relay can be used.

Bigger loads like large motors may need drives and containers. Some even have speed control. Big doors are more difficult to open and close. safety features needed.

The picture above shows also reed relays that are used for small signals - analog and telecom. In Solid State switching also we have small signal and power switches, using mosfet or triac.

Soldermans Basic Electronics: Relays and Contactors

Jim: let me check dis addr nd i'll get back 2 u just now.
Jim: ok but if i have a problem i'll get back 2 u,bye

Thursday, February 13, 2020

Soldering Iron Tip

Can I use stainless steel to replace a defective soldering iron tip?

mail from EA

Soldering iron tips are mostly alloys of copper. the thermal conductivity of steel is poor. buy a soldering iron tip available in the local market.

This image has a Tip for Soldering Iron and also has Soldering Iron Tips.

Soldering Iron Tip

Change Weller ET Series Soldering Tips

Changing the soldering tips on a PES51 pencil is very simple. You just have to make sure to take your time and don't force anything. Damaging your iron is not only possible, but easy when replacing the tips, so proceed with care.

Weller tips are magnetic and only original weller tips to be used.

The Basic Electronics Soldering & Desoldering Guide

The Basic Soldering Guide contains everything the beginner needs to solder electronics successfully, with guidance on choosing the right soldering iron, details of various solders and fluxes,

delabs

Thursday, February 06, 2020

Passive volume control

please if you don't mind I need to help to find a control circuit for volume of speaker 4 ohm or 8 ohm located in the another room far away of cassette or CD player by using only passive components with potentiometer without transformer.

mail from AD



i have attached to this mail a simple circuit you can build at home at low cost. This is the only alternative for the need that you have specified. it uses just a rotary switch and wire wound resistors.

Home Made Circuits

Volume control circuit for speaker 4 ohm or 8 ohm located in the another room far away. by using only passive components. This gives limited control and helps reduce volume when a conversation starts. The resistors are very low value.

Passive volume control with Potentiometer

A simple circuit you can build at home at low cost it uses just a rotary switch and wire wound resistors. Add more resistors and a rotary switch with more contacts for finer control.

delabs


Monday, January 13, 2020

Seven Segment LED display

how is the circuit for driving a seven segment led

mail from EA

A 7 segment LED display is used to display a number 0-9 using 7 LEDs, The circuit you design must have a BCD output, BCD means Binary coded decimal for number 0 it is 0000 and for number 9 it is 1001 see this chart i put in my site....  Electrical Tables

the BCD is fed to a BCD to 7 segment decoder like CD4511 or 7447 which has the logic to take care to drive your display, the displays are two types common anode and common cathode you have choose a driver to match your display, you will need to use current limiting resistors for every LED to limit current to 15mA or less. there are many circuits in my website which has examples of these.

Seven Segment LED display

you can also drive such displays with 7107 or 7135 to display analog signals, or with a microcontroller like 8051 using software decoding, even such examples and code is available at my website.Digital-Circuits. and Logic-Circuits.

delabs

I made an online tutorial for seven segment LED. Hope it helps you learn more.

Digital up down BCD counter "Simple Digital up down counter CD4029, with interactive javascript simulation." You can run the circuit online and try out without wiring it up.

delabs


Extra Extra !