Many graphic LCDs require multiple positive and negative supply voltages. At “power on” and “power off,” these bias voltages must be sequenced properly, along with the LCD’s data and control signals, to prevent damage to the LCDs...
Articles and news - 8
Sequence Generator Delays Bias Voltages To LCDs
Magnetic-field probe requires few components
Popularly known as “gauss meters,” various makes and models of magnetic field meters are available on the market at prices that make them unaffordable to many hobbyists and engineers...
Drive LDOs To 0-V Output With Single Supply
Many electronics circuits begin operation at voltages below 1.25 V. But popular adjustable regulators such as the LM317, LM350, and LM338 can provide output voltages only above 1.25 V, and the L200 minimum is higher at 2.85 V...
Linear Monostable Converts Capacitive Transducer Measurements into Pulse Train
The circuit allows you to convert capacitance into a pulse train by using a constant current source and a linear monostable formed by two NAND-gate chips...
Supply Constant Power Level To A Varying Load Impedance
How do you deliver constant power when the load impedance isn't constant? That problem arises, for example, in trying to maintain a warm LCD display on an outdoor gas pump in cold climates...
Adding Feedback Boosts Peak Detector's Precision
A signal’s peak is typically measured with a diode. But if the diode is used alone, the input voltage must be much larger than the diode’s turn-on voltage to obtain acceptable accuracy...
Dynamic siphon steals current from USB port
A USB port offers a handy source of 5 V power for auxiliary devices. A USB port not only supplies power to a microcontroller and other essential circuitry, but also provides enough extra current head room to charge a small battery or supercapacitor energy-storage element...
Single LED Takes On Both Light-Emitting And Detecting Duties
By adding just two MCU I/O pins, a standard LED can also perform as a light-detecting photodiode. Sometimes people forget that light-emitting diodes can also detect light quite well...
Automatic latch-off circuit saves batteries
Although rechargeable batteries offer many advantages, they can suffer damage and shortened service lives if they're fully drained of their charge. The circuit shuts off a battery-powered appliance – in this instance, an LED flashlight receiving power from NiMH...
Volume-unit meter spans 60-dB dynamic range
An audio volume-unit meter displays peak-related audio amplitudes to aid in accurately setting recording levels or for displaying an amplifier's operating conditions...
