All Electronics Hobby Projects. You can build quickly them when have free times. Most cheap and easy to find parts.
This is a 3A adjustable regulators using IC-LM350 that looks like LM317 Variable DC Power Supply, but high current higher 3A, adjust voltage 1.2V to 30V
This is simple Solar plant watering alarm circuit. It will sound alarms when the soil is dry. The trees have died. It the solar sell is 6V DC power supply
The special Relay that used replace normally relay, very fast contact load, low voltage input 3V to 24V only
It is guitar amplifier circuit diagram with pcb layout. Power output at 200 watt in super bridge model so help to you have a high quality circuit in cheap. [...]
This is simple hight power LED flashlight,we use 24 LEDs super bright for display and 3 AA batteries and resistor for limit current so cheaper.