Category «Power Supply»

5 A Constant Voltage-Constant Current Regulator

A constant voltage constant current  (CVCS) regulator  doesn’t mean a system with a constant load, since there will be no regulation in such case.  What we call CVCS regulator is a regulator with two modes. The first mode is constant voltage, where the regulator trying to regulate the supply to a variable load at a …

Fast Charger for Better Lead-Acid Battery Life

Compromising between the speed while maintaining safe operation for battery charging is an interesting challenge. This circuit can be used to charge a battery , and it’s safe and  rapid.  To get quickly charged, this circuit charge with initial charging voltage of 2.5V per cell.  To keep it safe, this circuit prevent the battery from …

TLC497CN Negative Supply Generator

Negative supply from positive supply is needed if the circuit need both positive and negative supply while we have only positive supply. The circuit shown in the schematic diagram below is a negative supply generator, built using a TLC497CN integrated circuit. The TLC497CN is used as the main switching  circuit, and it can provide negative …

Three Cells Produce Regulated 3V – 3.3V

Three NiCad and NiMH batteries can be used to produce 3V/3.3V supply voltage. This can be done by this linear regulator circuit. This circuit uses an ICL7611 micropower op amp and MAX872 voltage reference. This regulator can be used to replace the charge pump or a switching regulator. The dropout characteristics of this circuit depends …

High-Voltage Generator with HEX FET

The schematic diagram below show a circuit of high voltage generator. This circuit uses a 4049 hex inverter as an oscillator, and you can use ignition transformer from automotive engine. A fly-back transformer is possibly usable too. The 4049 will drive the IRF731 HEX FET. The Q1 must be heatsinked. Here is the schematic diagram …

Main Power-Battery Backup Switcher

The schematic diagram shown below is a battery backup regulator circuit, useful for memory or other low power (battery operated) but critical circuit (must continue operation on powerline failure). The one LT020 will not conduct in under line-powered condition, made possible by means of of feedback string’s arrangement. In case of main power failure, the …

Ni-Cad Battery Zapper, A Rechargeable Battery Reconditioner

Ni-Cad (NiCd, NiCad) battery, sometimes doesn’t work as expected, gives no power and cannot be recharged. In this situation, the battery need to be reconditioned. It’ is possible that the battery is internally shorted, and we can get the battery into life again by recondition the Ni-Cad battery using a zapper circuit. This circuit restore …