Circuits & Schematics Supply

You can improve a current sink's accuracy by at least two orders of magnitude by adding two standard 1%-tolerance resistors. As a bonus, you also compensate for errors that a low-current-gain pass transistor's base current introduces. To do ...

Many people consider white LEDs to be the future of lighting. Strung together, several LEDs can replace an incandescent lamp or a compact fluorescent lamp. High-power white LEDs need a dc voltage of about 3.6 V at a current of about 350 mA to ...

No matter what portable power source you use, the lower the starting voltage your circuitry operates at, the better. A lower startup voltage also maximizes runtime. Furthermore, to completely discharge the power source, circuitry must run on ...

Fellow engineer Sanjay R. Chendvankar of Mumbai, India, recently offered a novel way of reducing current through a relay coil ( see Ref. 1 ). His idea utilized an unused normally closed pair of contacts of that relay to reduce the driving voltage ...

This circuit drives a resistive heater element with a low-frequency, pulse-width-modulation (PWM) voltage source, providing heat output that’s directly and linearly proportional to the duty cycle of the drive signal. The circuit’s ...

Today's digital ICs typically demand complex voltage sequencing, a task that usually requires dedicated ICs or microprocessors. But what if your requirements are more modest? The sequencing scheme presented here requires only a single ...

Linear regulator ICs offer simple, efficient, and effective solutions in a multitude of low- to moderate-power voltage regulation applications. They also provide opportunities for many simple application tricks that stretch their performance and ...

Performance under transient loads has become the most important specification of voltage regulators used to power a wide array of products whose current demands vary quickly during operation. Testing transient performance requires a load that can ...

With their excellent isolation and reliability, gate-drive transformers (GDTs) are commonly used for driving half-bridge power circuits. However, they pose challenges when you want to have both switches off for an extended period. This application ...

For some ICs, supply voltages should be applied in a particular sequence. One example is the subscriber line interface circuit (SLIC), which, depending on the application, may require several negative and/or positive voltages. The larger voltages ...