Free Circuit Diagram

A constant-current/constant-voltage linear charger for single-cell lithium-ion (li-ion) can be constructed using only a tiny battery charger controller chip EUP8054 and a few passive components. This tiny integrated circuit chip is suitable for various portable devices. This controller chip is also compatible with USB power specification, ideal for charging the battery when the device is [...]

This charger circuit is suitable for lead-acid battery, including flooded, gel, and AGM types. The automatic term means that this charger will stop charging automatically when the battery voltage reach a certain pint, indicating that the battery has been fully charged, and charging will be restarted if the battery voltage falls below that threshold. A [...]

If only a 5 volt positive supply is available and you need a negative voltage for op-amp or other biasing purpose, the you can generate the negative supply from the positive supply using this circuit.

This circuit give same functionality with our previous 555 switching circuit, but now we use a CMOS inverter gate. Using CMOS [...]

The circuit below is the basic for standard symmetrical power supply. If your circuit need high current then this circuit is suitable. Here you can see the circuit’s schematic diagram.

You need a center-tapped transformer to build this symmetric power supply. This power supply circuit is widely used in op-amp application, as well as in high-rated [...]

This simple Batteries charger circuit is designed for NiMH/NiCd batteries. It need no micro-controller nor any programming. Linear Technology Corporation produce the LTC4060, an autonomous 1- to 4-cell, 0.4A to 2A linear NiMH and NiCd battery charger complete controller. Here are the main features:

No Sense Resistor or Blocking Diode Required
Complete Fast Charger Controller [...]