Revealing the Ideas behind Circuits
Circuit Idea ? >> !
"Electronic circuitry is more art than science. Inventing novel electronic circuits is a result of human fantasy, imagination and enthusiasm. Fortunately, abstract electronic circuits are based on clear and simple ideas, which we may derive from our human routine. In order to really understand how circuits operate, we have first to reveal the basic ideas on which they are grounded..."
This circuit is used to detect objects by reflected infrared light. It can be built into a cylindrical enclosure just like an inductive proximity switch. This is also useful as a level detector for colored liquids like oil. This has some immunity to ambient sunlight as it detects ac pulses.
This is a Hand Crafted PCB Artwork done by a PCB Vendor years back, this method may be used even today.
PCB Design -
This Layout may have many jumpers and may need to be cleared of Hairline shorts which has happened after i scanned it, cleaned it and enhanced it using image manipulation software.
This PCB would go into a 30mm Nickel Plated Brass threaded tube, with Epoxy or Teflon ends. These were turned components as quantities made were small. An Optical Proximity Sensor that would fit the same place as the eddy current or Inductive sensors, in existing machines. It could work a longer distance and could detect Non-Metals and even translucent fluids.
You can design your own PCB with CadSoft Eagle Layout Editor. Laser prints of output works well, but even Ink Jet printouts will work fine for small PCB's like this. Take 3x or 4x prints.
Electronic Educational Applets - Paul Falstad
"These are some educational java applets I wrote to help visualize various concepts in math, physics, and engineering." - Paul Falstad
Here is a 4-20 mA In/Out Analog Mux with Cascade option. This is a simple circuit i designed to make a Automation System within a budget.
This takes 4-20mA from many Transmitters and gives out just one 4-20 mA output. The Mux is done with a digital byte or word. This is a slow scanner as process is slow, that way many analog inputs can be multiplexed and sent into one analog input of a D/A. In near real time systems a faster mux could be used or mux totally avoided. This was made in some numbers, so the pcb is better than others.
This is a SMPS Circuit application very close to the Application Note in the book SGS Motion Control Application Manual. This worked well. Read about SG2525 - SG3525 - PWM SMPS Regulator Chip.
Some Notes Related to the Project
Magnetics Design
All Transformers Isolation 1kV PRI To SEC / SEC To SEC / PRI,SEC To Core. Use Yellow Mylar Tape Insulation or better for all. Vacuum Impregnate all Magnetics in Epoxy or Varnish. All Power Tracks on PCB reinforce with Copper Braid.
TRX1 Mosfet Drive Transformer
T25.0 MGQ-5L Hitachi - Type Torroid - 100khz Signal
486T250-3C8 Ferroxcube - SEC1 And SEC2 Antiphase
TRX2 Stepdown Invertor Transformer
EC52 Siemens/Hitachi - Can Be ETD/EER Cosmo Ferrites
Coper Strap/Ribbon used, cause Hi-Freq Skin Effects, PRI 2 Wires paralleled for same reason.
EC52-3C8 Ferroxcube Phillips
Trx3 Current Feedback Trx
T25.0 MGQ-5L Hitachi - Type Torroid - 100khz Signal
486T250-3C8 Ferroxcube
L1 Series 60A-80A Inductor
Type EC/ETD/EER EC42 Hitachi - Air Gap In Inductor Core Both Sides
100khz Power IF30-3C8 Ferroxcube - 6 Turns 4*#12 AWG In Parallel
4 Wires Of 12 AWG Twisted & Wound For 6 Turns (Use Less AWG For Less I)
TRX5 50hz Transformer Small
TRX4
This is A 10mH Common Mode Filter
The Reference Application on ST Half Bridge Convertor - SG3525
PCB Layout
The PCB of module will be added later, if i locate it. It is small and be designed easily.
This is the RTD Signal Amplifier part of Temperature Controller or Indicator. The card also contains a relay on-off control circuit.
The Circuits are -
The PCB Boards -
