Circuits & Schematics - Supply - 5

A high-side current-sense amplifier, IC 1 , offers a simple method of combining low-speed clocks or other signals with dc power in cables between subsystems (Figure 1). Designed for monitoring charge and discharge current in secondary batteries, IC ...

Latching relays change their states when you apply a short voltage pulse to their coils. Because these relays require no continuous coil currents to keep their states, you can save considerable power in the driver circuit. In one type of latching ...

In recent EDN design ideas, we’ve seen thermostat designs that meld the functions of sensor and heater into a single device: FET, BJT, or even a simple length of fine gauge copper wire. A virtue inherent in thermostat designs that use a ...

One option for driving high-brightness LEDs uses the standard stepdown buck converter (Figure 1). The sense resistor, R S , generates a feedback voltage, V FB , that sets the desired LED current, I LED , according to the equation Figure 1. A ...

Battery stack voltage monitor development ( Reference 1 ) is aided by a floating, variable potential battery simulator. This capability permits monitor accuracy verification over a wide range of battery voltage. The floating battery simulator is ...

The fuse described in this design idea does not drop the connection, it simply limits the output current. A behavior that is similar to a polyfuse, however the circuit shown in Figure 1 is more accurate, does not depend on ambient temperature ...

Editor’s note:Battery charging in a float or maintenance mode has been around for a while, especially for standby power, emergency lighting, telecom, uninterruptible power, and other critical power needs. The float method of charging is a ...

Included among the many applications for pulse-width modulation (PWM) are voltage regulation, power-level control, and fan-speed control. A PWM circuit for such systems can be implemented with three op amps on a single quad-op-amp chip (Fig. 1). ...

This circuit of only a few components is powered by two AA batteries and features a mode that extends its power savings. Imagine a smart light switch which not only automatically turns itself on when it gets dark, but also adjusts its level of ...

This Design Idea mates a precision current source IC with precision difference amp chips to create a programmable current source or sink. The resistor-programmable current source/sink in Figure 1 illustrates the basic topology, taking advantage of ...