Electronics lesson: electronic parts, electronic components, electronic projects, circuit diagram and more
Well, the following circuit is a power supply circuit which build without transformer/transformator component inside the circuit (transformerless powersupply). This is a great way to get 20A current output power supply without transformer since 20A transformer is very-very expensive.
Schematic diagram:
PCB layout:
This is a two-zone alarm which featured with automatic exit, entry and siren cut-off timers. The circuit will activate the alarm if any intruder entering the zone/room.
When you move SW1 to the Set position – you have about 30 seconds to leave the building. If you re-enter through the Exit/Entry zone – the buzzer will sound – and you’ll have about 30 seconds to switch the alarm off. The Instant zone has no entry delay. Anyone entering through the Instant zone – will sound the siren immediately.
The following diagram is the schematic diagram of Lithium battery charger. Featured with overcharging protection, your lithium battery will be more durable and not easily damaged.
Charging is accomplished with a constant current of 60 mA for AA cells to a cutoff of 2.4V per cell, at which point the charge must be terminated. The charging system shown is designed for multi-cell battery pack of 2 to 6 series connected cell or series/paralel arrangements.
