How To Build SOHO Small Office Home Office with free software and small budget ?

The SOHO (Small Office Home Office) Design with 12- 20 Employee or user 

As in digital business era, small office or home office be required using computer and printer for easy correspondence inside and outside office to contact another company, or customer, making letter, report, and electronic mail etc.

This also required computer Network for sharing Printer and another Network Equipment for low cost.

As we know open sources is community of developer and provide many option of software that can be used for building small office or home office with small business that can reduce cost for providing Network in his/her office with quality same as, and more than  others software that must be paid.

For this reason it needs education for The office owner and IT Team , also employees who using this advantage of open source for daily activity in office.

For this purpose We will needs this material :

Computer / Desktop as Server 

Printer

Router

Modem

Notebook / Desktop with Wi-Fi card inside 

Software :

Ubuntu Linux  Operating System Server

Ubuntu Linux  Operating System/Chrome OS for desktop/notebook (Same function as Windows 10/8/7)

Libre Office or openoffice for Notebook and Desktop (same function as Microsoft Office)

Kmail (Same function as Microsoft Outlook )

Thunderbird/Mozilla as Browser

Many Opensource software you can maximize using it for start a small business or office with free of charge.

These all software you can get free of charge, the cost will appear on Computer , Printer, Wireless Router, Modem from ISP (Internet Service Provider), Monthly Internet Billing, and Notebook.

Implementation 

Download Ubuntu Linux Server here

Download Ubuntu Linux OS/Chrome OS for Desktop/Notebook

Notebook Lenovo Chromebook Flex 5 2-in-1 Laptop

Do not Throw your Old Computer

If still have an old computer PC with i386 Processor, maybe you can still used it and take advantage from this old computer with open source software.
You can install Unix Operating System such as FreeBSD Unix or Linux Operating System.

The hardware minimum system for Installing Free BSD is :

32bit x86 Intel Processor such i386, 80486 or higher CPU with minimum 64MB RAM or 128MB RAM with 1.5 GB hard drive memory.

amd64 Processor , inlcude AMD Athlon, AMD opteron , multi core Intel xeon, and Intel core 2.

While for Linux Operating System support Processor Intel 80386, 80486, Pentium, Pentium Pro, Pentium II, Pentium III CPU, these includes processors such 386SX, 486SX, 486DX, and 486DX2, included Cyrix Processor and AMD Processor.

The Advantage of Old computer is for small business industry and home small business owner , you can have low cost for software and hardware budget for running your business. You can email, browsing, also make spreadsheet calculation and financial plan and accounting also office function can be done with Libre Office , and printing also can be done. Simplify this, you can have your own business office with old computer and old printer, also you need router for connecting to Internet.

For Example I used Opensuse Linux for my notebook. So I do not have to worry about copyright issue software. Because all software that I need for working in home are open source such as Libre Office, KMail, etc.

This is capture from my notebook , I use opensuse for Operating System.

 

And for Using Printer, We use share printer in the home network. Although the Server we use still using Windows OS 7 , because it is not belong to me. But The Ideas of this plan is to reduce or minimize your SOHO or small business from taking his/her budget from capital for buying expensive system of small hone network computer. And you can still save your budget for other used.

And here it is how I setting my notebook connecting to Wireless printer outside of my room.

I am using Motorolla Modem, TPLink Router, Sony Vaio Notebook and PC Intel Computer  

4G LTE 4 Pole Inter Digital Filter for Digital TV

This is the design of 4G LTE filter for Digital TV . As we know some of 4G LTE transmit frequency , overlapping with Digital TV reception frequency on 698 - 806 MHz. So, this 4 Pole Inter digital Filter made from aluminium plate and copper rod. You can experiment with it , I am not tested yet, for another design you can follow from VK3UM software online at VK3UM.com

LM 335 Temperature Sensor Circuit

Temperature Control Circuit :

Image Courtesy Texas Instrument

The temperature controller circuit using +5 V voltage source from I/O slot at IBM PC/XT/AT.

IC LM 335 from Texas Instrument have the ability to detect temperature from ranging -40 celcius degree until 100 celcius degree.

This LM 335 from Texas Instrument , is zener diode which have the linear coefficient voltage increment related with increment of temperature with formula :

Vz = + 10 mV/ C (celcius degree) , with current opeartion between 400 uA until 5 mA.

On the circuit Resistor 2.2 K use for limit the current flow to cathode pin from LM 335 which is output of LM 335 sensor temperature.

On circuit Resistance of R is 2.2 K , and at 25 Celcius degree from data sheet of LM 335 , voltage at LM 335 will be 2.982 Volt , so current flow can be calculate :

Vcc = + 5 V

Voltage at 25 Celcius on LM 335 = 2.982 V

Voltage at Resistor R 2.2K is = 2.018 V

Current flow through LM 335 and R will be = 2.018 V / 2.2 K = 0.9 mA

This 0.9 mA current at LM 335 still on at range of sensor LM 335, and then the output cathode pin of LM 335 sensor from Texas Instrument connect to input 0 of ADC0809 Analog and Digital convertion data from Texas Instrument at pin 26.

Temperature Sensor LM 335 from Texas Instrument

Temperature Sensor using IC LM 335 from Texas Instrument. LM 335 is Zener Diode which sensitive of temperature change in it surrounding , which is reverse bias on it breakdown area with output :

Vz = [10 mV/Kelvin] …..........[2-1]

Because there is gap different 273 degree between Kelvin and Celcius , so the output in Celcius for LM 335 from Texas Instrument will be :

Vz = 2.73 Volt + [ 10 mV/Celcius] T.........[2-2]

where T is in Celcius Degree

IC LM 335 from Texas Instrument have temperature range between -40 celcius degree – 100 celcius degree

I use LM 335 in Plastic Package TO-92 , another package for LM 335 is SOIC 

Images courtesy Texas Instrument

Another IC temperature sensors from Texas Instrument are LM135, LM135A with TO-46 package, LM235 and LM235A in TO-92 package and LM 335 and LM 335A in SOIC package.

From this writing, I want to discuss about Simulation control system with IBM PC 

XT/AT for Temperature, heater, and pump using LM 335 as sensor, PIO 8255, ADC 0809 , MOC  from motorolla , and TRIAC .

This control system operate with software with QBasic , and I will write the schematic diagram, implementation, and software design.

For more data about LM335/LM335A . please visit data from Texas Instrument , here