Here is an ancestor of the product in the earlier post. It is a Process Scanner and Indicator. There was no control, but there were individual alarms for each channel.
This is a original design of mine, obsolete now due to size and technology. The inspiration of the product concept was from a Omega Catalog Item. Even today i use the Omega catalog for inspiration, but i do not design complete products, only circuit sections.
Read more about Control Instruments at my pages here
Flextek Electronics located at Carlsbad-CA have created a design that helps a design engineer understand the intricacies of digital supply design using a Micrcontroller. – delabs
8-Buck Converter Design Kit enables customer to build, program, test, and analyze a Buck converter controlled by 8-bit PIC Micro. Highly integrated components execute control functions through firmware algorithms that are converted to analog circuits for analysis and intuitive understanding
The 80W converter has 12V input with output adjustable from 1V to 11V on a through-hole PCB measuring 3.6″ x 1.5″. Key performance parameters include 92% efficiency and 12mVrms ripple at 156KHz switching frequency.
“Flextek Electronics has extensive expertise in electronic controls, closed-loop control systems, embedded real-time controllers, analog circuits and power management, as well as software development.”
Temperature Sensors like Thermocouples need cold junction compensation as a part of front end signal conditioning, this is done at the terminal block where the Thermocouple wires are terminated. This design has to be more accurate and broad, if the design we make has to work well in both Tropical and Temperate Climate Zones.
LM335 Cold Junction Compensation
Another Method using a Copper Resistor
If wires of two dissimilar metals are joined at both the ends and the junction formed at one of the ends, is heated more than the other junction, a current flows in the circuit due to Seebeck thermal emf. This effect is used in thermocouple temperature sensors.
The Peltier effect is the converse of above Seebeck effect, which means that if a current is forced through junctions of dissimilar metals, the junction will generate heat or absorb heat (cooling) depending on direction of the applied emf. This effect is used to make portable and small refrigerators.
Thermocouple Temperature DPM – DMM
The MAX1561 and MAX1599 include an internal, high-voltage, low-RDS(ON) N-channel MOSFET switch for high efficiency and maximum battery life. A single DualMode input provides a simple means of brightness adjustment and on/off control.
MAX1561 – 26V Step-Up Converters – Maxim IC
“High-Efficiency, 26V Step-Up Converters for Two to Six White LEDs”
Fast 1MHz (500kHz for the MAX1599) current-mode, pulse-width modulated (PWM) operation allows for small input and output capacitors and a small inductor while minimizing ripple on the input supply/battery. Programmable soft-start eliminates inrush current during startup.
Some Features –
- Accurate Current Regulation for Uniform Illumination
- High Efficiency Up to 87%
- 2.6V to 5.5V Input Range
- 0.3µA Shutdown Current
- 26V (max) Output with Overvoltage Protection
- Up to 900mW Output Power with Internal 30V MOSFET Switch
Why Drive White LEDs with Constant Current? – Maxim
Here you can understand how to drive white LED’ s for flashlight or Internal lamp. I have tried substituting for tubelights and bulbs. These LED’s are amazing. The amount of light at even 100mW is phenomenal. The future is indeed LED Lights. But more Amber component is required in LED to give the warm feeling of an Edison Lamp.
Electromagnetic interference (or EMI, also called radio-frequency interference or RFI when in radio frequency) is disturbance that affects an electrical circuit due to either electromagnetic induction or electromagnetic radiation emitted from an external source.
Electromagnetic interference Wiki
Vertical polarized VHF- UHF biconical antenna
170 – 1100 MHz with omni directional H-plane pattern
Who would know better about Radio Frequency Interference and ElectroMagnetic Interference more than the Hams or Amateur Radio Community.
If they have to communicate effectively using limited resources, they have to deal with EMI/RFI effectively, While they build their equipment or combat Noise from other Machines and Installations nearby.
This problem needs more practical involvement and experimentation to learn, compared to learning something like Digital Electronics.
Equipment and Electricals like SMPS, AC/DC Drives, Motors, Solenoids and CFL Lamps are to be built/reinforced for low EMI/RFI emission/radiation.
Sensitive Medical Equipment like ECG or even a Aircraft can be seriously affected by Noise.
Radio Frequency Interference (RFI)
One chip that takes care of all Power requirements in a Portable Electronic Gadget. Power Management Multi-Channel IC (PMIC) Solutions – PMIC Solutions with and without Battery Charger.
TPS65070 Handheld Gadget Power Chip
A battery charger for single Li-Ion or Li-Polymer cell. The voltages needed for an embedded system. Includes PWM mode using I2C. wLED Boost Converter, Touch Screen Interface. 10 Bit A/D Converter too.
Charger/Power Path Management:
- 2A Output Current on the Power Path
- Linear Charger; 1.5A Maximum Charge
- I Limit – 100mA/500mA/ 800mA/1300mA
- Thermal Regulation, Safety Timers
- Temperature Sense Input
Battery charging, gauging and protection
“As different battery technologies like Lithium Iron Phosphate (LiFePO4) and Super Capacitor are becoming more popular, TI ……….”
A Circuit for charging NiCd, NiMH and Lithium-Ion Batteries.PWM 500kHz with Soft Start and Shutdown Control.
Linear Technology – LT1510 – CV CC Battery Charger
Some things to know in battery charging. A battery that has drained will almost appear like a short circuit to the charger. A battery is never fully drained, if you want a nice battery life. Overcharging a battery can damage it and is not safe too. We have to charge it with an optimum current, upto a Top up charge voltage only. Then a trickle to compensate for internal leakage on no-load. Float charging and Cyclic charging are some popular methods.
LT1510 – CC CV Battery Charger
It can charge lithium-ion (Li-Ion), nickel-metal-hydride (NiMH) and nickel-cadmium (NiCd). These require constant-current and constant-voltage charging. A 2A peak current switch for Boost Charging may be helpful for charging Lead Acid Batteries too. A 0.1 ohm current sense shunt makes charging current programmable.