Circuits & Schematics - 3

Portable battery-powered devices often spend most of their life in standby mode, in which the quiescent current of an internal boost converter continuously bleeds the battery. The quiescent current during standby can be larger than the actual load ...

The simple circuit design in Figure 1 lets you measure all components of a current flowing in a dc servo motor. The rectified output of the circuit uses ground as a reference, so you can measure the output by using a single-ended A/D converter. The ...

Just plug the device with an SD card inside into any USB port. It creates an FTP server where we can send and receive data to the SD card. USB was supposed to be universal, and the main goal was to make a hot-swappable, super easy to interface with ...

Supervisory circuits normally monitor a microprocessor's supply voltage, asserting reset to the IC during power-up, power-down, and brownout. In this way, the circuit ensures that the supply voltage is stable before the microprocessor boots, ...

The easy way to clamp a signal to a given value is to use two zener diodes, connected back-to-back. This method has several disadvantages. The accuracy of the clamping depends on the tolerance of the zener diodes, and the clamping is not ...

Fan noise is becoming a significant issue as electronic equipment increasingly enters the office and the home. Noise is proportional to fan speed, and the airflow hence, fan speed necessary for cooling is less at low ambient temperatures. Because ...

P-channel MOSFETs can simplify designs when you use them as high-side switches on circuits with voltages exceeding 100 V dc. When driving a MOSFET, you must rapidly charge and discharge the input capacitance between its gate and its source to ...

A designer who uses a phototransistor to convert a modulated optical signal to an electrical signal frequently encounters problems when high-intensity background light saturates the phototransistor. When its base terminal floats, a ...

This Design Idea describes a single white-LED torch, which can be housed in an empty glue-stick tube and has a long rechargeable-battery life. The circuit is constructed with just a few commonly available parts. This torch has proven to be highly ...

EDN The circuit in Figure 1 provides 32 steps of brightness control from 0 to 100% for a backlight or instrument panel, using just two general-purpose-microprocessor signals. In addition, the circuit requires little board space, because it uses ...