Friday, November 21, 2014

digital weight Indicator

I need some details of a digital weight Indicator.

mail from CA

study these useful links.......

Introduction to Load Cells at Omega

A load cell is a transducer which converts force into a measurable electrical output

LC101 and LC111 Series:S-Beam Load Cells

LC101 S-Beam Load Cell

S-Beam Load Cells S-Beam load cells get their name from their S shape. S-Beam load cells can provide an output if under tension or compression.

Measuring Strain with Strain Gauges at NI

"The metallic strain gage consists of a very fine wire or, more commonly, metallic foil arranged in a grid pattern."

 Bonded Metallic Strain Gage


Wednesday, November 19, 2014

Electronic Fifteen LED Roulette

The following was submitted on July 11th, 2007 at 12:47AM (PDT). Message: I want to combine Ne555 with 74154 IC.The indication of the outputs must be shown with LED's but up to so far it need 15 outputs ,is it possible the way i did? if not i will need your assistance

Mail from CY

LED running lights are used to decorate Christmas Trees, Festival Surroundings and even  Buildings. A Clock and a counter are basically required. Many LEDs can be used in parallel with driver transistors. Upto 15 count is is good enough. Many colors can be used and with a PWM or VCO you can make it Audio or Music effects lights like strobe lights.

Electronique RĂ©alisations - Roulette

Multi-Colored LEDs and drivers and even PIC microelectronics with Visual Effects in the form of ROM tables can make Alphabets and Numbers appear in LED arrays. Some have made Mini Ocillosocpes and Toy Spectrum Analyzers too in LED DOT Matrix Arrays.

LED Sequencer Circuit

Electronic LED Roulette

See these circuits you will get an idea, Using CD4514 is also possible.

555 and CD4017 Running Lights


Monday, November 10, 2014

Isolated Full-duplex Serial Interface

I would like to build Optoisolated RS232 interface. I've googled a little bit, and I came across your design:

RS232 with Opto-Isolation

However presented schematic is of poor quality - I'm not able to read all parts numbers and their values. Is it possible for you to send me a copy of this schematic, which is more readible?

Mail from M from Poland

You had written to me a few months back, I suggest this circuit

Isolated Full-duplex Rs232 Interface

This self powered interface circuit electrically isolates the TxD and RxD lines from the PC serial port and protect the PC from direct connection to hazardous voltages.

See also Isloated Interface to Microcontroller

See a Commercial Solution you can buy

CVT-232A-3 port-powered 3-wire RS232 Isolator

CVT-232A-3 port-powered 3-wire RS232 Isolator

"The unit features 5000V opto-isolation circuitry and optically isolates three (3) RS-232 lines (TX, RX and GND), which effectively protects your RS-232 devices from ground loops, noise problems, transient surges, remote lightning and spikes."