Circuits & Schematics - 7

By decoding the commands sent by a direct-broadcast satellite receiver that uses the DISEqC (digital-satellite-equipment-control) protocol, you can troubleshoot the commands or simply listen in. Eutelsat Corp offers the DISEqC protocol. The ...

Powering LEDs from a wide dc range say, 30 to 380 V without wasting a lot of power in the regulating block, is a difficult task when the LED current needs to be constant. Dedicated LED drivers are available, but they usually implement boost ...

This design idea (Figure 1) shows how easily “new flesh can be added to the old bones” and how some new functions can be added to the simple LED display that was published earlier ( Reference 1 ). Figure 1. Upgraded simple LED display ...

Surprising facts, like “old fangled” 3-leg linear regulators ( LM317 , LM337 , LM350, et al.) can be used in shunt regulator topologies ( Reference 1 ) can sometimes inspire “new fangled” circuit designs. Figure 1 shows a ...

Many applications involve the digital synthesis of three-phase sinusoidal waveforms, such as ac-motor drives, active power filters, and grid-voltage synchronizers, that use a microcontroller or a DSP for digital control. You can perform this ...

“The unfortunate relationship between servo systems and oscillators is very apparent in thermal-control systems,” said Linear Technology's Jim Williams ( Reference 1 ). Although high-performance temperature control looks simple in ...

The purpose of this Design Idea was to improve reliability, add new features, and replace a latching power switch with a momentary one. The features are: The switch has foolproof protection against too frequent switching, which can be harmful for ...

Streetlights, emergency lights, and security lights must automatically turn on when it gets dark. You base the control circuit on the resistance of a photoresistor or another LDR (light-dependent resistor) that varies with light intensity. An ...

A good manually adjusted audio gain stage is characterized by: Low noise and low distortion, A 20 kHz bandwidth, A wide gain adjustment range (e.g. 90 dB), and Logarithmic (at least pseudo-logarithmic) control characteristic to Efficiently span ...

The voltage-doubler circuit in Figure 1 can convert 2.5 V dc to 5 V dc or 1.8 V to 3.3 V. Most voltage doublers use an inductor, but this circuit doesn’t need one. The circuit uses a capacitor, C, by charging it through serially connected ...