Free Circuit Diagram

Electroscope is a device that is used to detect electrostatic charges. Operation: To reduce AC noise this circuit uses C1, but it will lower the sensitivity a bit. As a voltage divider we use the MPF102 and R1. The divider’s output will be about 4.5V diving a half-scale reading on M1, a 200-uA [...]

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 [...]

Many cheap battery chargers usually assume that charging the battery slowly is OK although the battery is already full of charges. All they do is usually charging the battery with constant current no matter if the battery is almost completely discharged or has been fully charged. Off course the battery wouldn’t be damaged immediately [...]

All of the necessary circuitry to optimally control the charge and hold cycle for sealed lead acid battery can be implemented using  UC2906 series of battery charger controllers.  These integrated circuits monitor and control both the output voltage and current of the charger through three separate charge states; a high current bulk-charge state, a controlled [...]

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 [...]

This battery charger circuit use a flyback converter topology, and implements a current-limited power supply to charge lead-acid batteries.  Here is the schematic diagram of the charger circuit: The flyback transformer provide isolation and voltage input range flexibility, event at supply voltage lower that the battery voltage. Monitoring the charging current is done [...]