Circuits & Schematics Supply - 6

Some circuits need a constant-current source that does not necessarily connect to a power-supply rail or to ground. The circuit in the Figure 1 shows a simple method for achieving that configuration. Figure 1. The simple method achieves a ...

Designers often use chargers with flyback topologies to quickly charge energy-storage capacitors (references 1 and 2 ). In a flyback topology, the energy transfer takes place only when the charger’s power MOSFET is off, which effectively ...

Two previous Design Ideas describe simple ways to automatically disconnect a battery from its load after a preset on period, which extends battery life (references 1 and 2). These circuits have little loss in standby operation, but they do draw ...

Energy meters, heating/ventilation/air-conditioning (HVAC) systems, and high-power equipments that run on three-phase ac inputs pose a challenge to power-supply designers because nominal input voltage can be as high as 540 V ac. The challenge ...

Low-voltage microcontrollers generally have been powered from a regulated supply, such as 1.8 to .6 V, and have very low current consumption, typically between 1 mA and 5 mA. Achieving an inexpensive, space-saving solution for effective conversion ...

Various switching regulator circuits exist to provide positive- to-negative conversion. Unfortunately, most controllers cannot sense the negative output directly; they require a positive feedback signal derived from the negative output. This ...

The circuits in Figures 1 and 2 shows a PWM (pulse-width-modulated) ramp generator that you can use in low-cost switch-mode dc/dc power supplies. Its supply voltage can range from 5 to 35 V dc, and you can set the output-ramp amplitude of 0.3 to 1 ...

With linear regulators, you measure dropout voltage, V IN V OUT , at the minimum input voltage for which the IC sustains regulation. Low dropout means longer battery life, because the load circuit continues to operate while the battery discharges ...

The circuit in Figure 1 allows standard TTL logic levels to safely drive a high-power dc load. The circuit provides for both signal and ground isolation as well as a solid-state circuit breaker. Figure 1. An overcurrent condition in this isolated ...

There are a surprising number of high output voltage applications for LTC’s micropower DC/DC converter family. These applications include electroluminescent panels, specialized sensing tubes and xenon strobes. One of the key features of the ...