Geekcreit00ae EU Plug 220V DIY LM317 Adjustable Voltage Power Supply Board Kit Instruction: http://img.banggood.com/file/products/20170616021631SKU215283.pdf
Features:
One way adjustable signal generator output. Convenient to provide the pulse signal With a logical pen function. For convenient the logic level of test circuit With one way buzzer. You can test the wires on and off (connect the wires to the power positive and signal input, the wire on - the buzzer sound). You can also test the low-frequency signal (input the signal from the signal input, if there is a signal, the buzzer sound)
Specifications:
Power: 2W Voltage: 220V Plug: EU plug Output voltage: 1.25V - 12V regulated output continuously adjustable. PCB board size: 7.3 x 6.8cm (W / L) Shell Size: 11 X 6.9 X 41.5cm (L / W / H) Weight: about 295g