A recent Design Idea, “Silly simple precision 0/20 mA to 4/20 mA converter,” by prolific DI contributor Stephen Woodward uses the venerable LM337 regulator in a creative configuration along with a few passive components, to translate an input 0-20 mA current source...
Another silly simple precision 0-20mA to 4/20mA converter
Short push, long push for sequential operation of multiple power supplies
Industrial systems normally use both analog and digital circuits. While digital circuits include microcontrollers that operate at 5 VDC, analog circuits operate generally at either 12 or 15 VDC...
IR distance ranger covers 1 to 20 cm
Commercially available IR distance rangers typically handle a 3- to 30-in. detection distance. Many times, it is necessary to determine smaller distances...
Classic constant current cascode
An important figure of merit for all precision constant current sources is their active impedance. Which is to say, just how “constant” is their output held against changes in applied voltage?...
Optically isolated overcurrent detector works from ac mains
The circuit in this Design Idea detects short-circuit faults or excess-current conditions in line-operated equipment, such as a UPS (uninterruptible power supply), across an isolation boundary...
Go for the gold with voltage-reference circuits
High-resolution mixed-signal devices present an interesting challenge as you try to find the right voltage-reference design. Although no universal approach exists for these voltage-reference designs, the circuit presents an interesting approach for greater-than-15-bit converters...
PIC32CM PL10 MCUs expand Microchip's Arm Cortex-M0+ portfolio
Microchip Technology has added PIC32CM PL10 MCUs to its PIC32C family of Arm Cortex-M0+ core devices...
Circuit controls inrush current in ac-operated power supplies
Large power supplies that operate from ac wall voltage have large input-filter capacitors. You must limit the inrush current to those capacitors. Otherwise, the supply may trip the ac circuit breaker, or you may damage the rectifier, filer chokes, or PCB (printed-circuit-board) traces...
5 octave linear(ish)-in-pitch power VCO
A few months back, frequent DI contributor Nick Cornford showed us some clever circuits using the TDA7052A audio amplifier as a power oscillator. His designs also demonstrate the utility of the 7052’s nifty DC antilog gain control input...
Sensing and power-generation circuits for a batteryless mobile PM2.5 monitoring system
Particulate matter (PM2.5) monitoring is a key public-health metric. Vehicle- and drone-mounted sensors can expand coverage, but many existing systems are too costly for broad deployment...