Warm tip: products for the material package, need children to do their own production, this solar aircraft can not fly Oh, can not go, understand the principle of solar energy. Principles for...
Transmitter course courseware The principle of radio receiving and transmitting is that the transmitter sends out current of different frequency and wavelength according to the requirements of...
Product Name: Science and Technology Small Production: Earthquake Alarm
Weight: about 55g
Dimensions: 8*6*12.5cm
Packing: opp self-sealing bag
General knowledge of seismograph: In 132 AD, Zhang...
Earthquake alarm principle: when shaking small production, the glass bead copper wire will contact the O-shaped lamp, the line is connected, and the buzzer will make drip sound. First, fix the...