Circuits & Schematics Power - 6

Sajjad Hajdar Electronic Design Most common current-limiting implementations have a voltage drop that’s too high for today's systems with their low-voltage supply rails; this design with its far lower voltage drop is a better fit. There ...

Gheorghe Plasoianu EDN Bench electronic loads are usually rated for voltages less than 100 V, which make it difficult to test high-voltage power supplies. This Design Idea offers an alternative: an inexpensive electronic load rated for 500 V or ...

Peter Miller EDN Like other simple, single-cell lithium-ion battery chargers, Microchip’s MCP73812 provides no means of indicating the charging status. You can remedy this situation by adding four components (Figure 1). Add one more LED, and ...

Chee Hua How EDN This Design Idea demonstrates a way to adjust the output voltage of a power supply, for OVP/UVP testing, margin-testing the load, voltage programmability, or any other reason. The circuit in Figure 1 is capable of bidirectional ...

Protect circuits from high current until a capacitor charges A high-power offline supply is nothing more than a half- or full-bridge dc/dc converter. Rectifying the ac line yields a dc voltage that feeds the converter. At power-supply turn-on, the ...

Alan Adamsky Electronic Design The two battery-simulator circuits described here can help you quickly test a battery charger under a normal battery condition and an over-discharged battery condition. The circuits let you set any voltage to see how ...

Jesus Rosales, Linear Technology Design Note 545 Introduction Industrial, telecom, medical and automotive applications use a wide variety of regulated voltages to operate effectively, including high voltage and negative rails. When the designer is ...

Peter Baxter EDN This Design Idea shows how to use a 63¢ (Q=1) microprocessor reset voltage detector IC in a relay coil drive circuit to greatly reduce the coil’s hold-in current. When asked to estimate the coil current of a small Omron ...

Michael Dunn EDN Most electronics today requires multiple supply voltages four or more rails is not uncommon. But if you're using multiple, unsynchronized DC-DC converters, you've not only got a sub-optimal design, you're asking for ...

Domenico Di Mario, Italy digilander.libero.it/bubblegate/ecircuit3.html This circuit was specifically designed to recharge alkaline cells. The unusual connection of the transistor in each charging unit will cause it to oscillate, on and off, thus ...