Power plant in a backpack

It’s getting dark. The sun is slowly setting towards the horizon. Dusk is coming. It’s still early to go to bed, I want to read and play chess.

For motorists, energy for lighting is provided by a rechargeable battery. But hikers can also use electric lighting with no less success – a pocket wind power station (Fig. 1). Its weight is about 1 kg, it can be easily disassembled and fits freely in a backpack, and the generator itself can be placed in a pocket.

Attach a bronze attachment to a regular bicycle dynamo (Fig. 2). To ensure trouble-free operation of the machine, install the No. 8100 thrust bearing so that its outer ring fits tightly onto the housing journal. The inner ring must rotate with the shaft. It is slightly pressed by a nozzle rigidly fixed to the shaft.

The windmill’s wings are made of duralumin. They consist of three rods and six blades. The rods are symmetrically put on the spindle of the attachment and screwed onto the friction pulley of the bicycle generator. The blades are connected to the rods using M3 bolts. All connections are secured with additional nuts.

Windmill rods can be made from steel strips or wooden slats measuring 12X20 mm; the blades can be replaced with plywood or cardboard. The cardboard must first be boiled in a mixture of 80-75 parts of drying oil and 20-25 parts of rosin, and then dried well in an oven or warm oven.

This achieves water resistance and significantly increases the strength of the product.

The wings (Fig. 3) are installed at an angle of 40-45°, and the bicycle generator itself is attached to the pole with its existing clamp so that its wings are oriented towards the wind.

The bicycle generator works on the charger (Fig. 4). The alternating current generated by the generator is rectified using diodes and supplied to charge D-0.2 type elements that form a battery.

You can take any rectifier diodes with a current of at least 100 mA. Diodes D7A – D7Zh, D206 – D211, DGTs27 are suitable here. To smooth out the pulsation, you can place an electrolytic capacitor with a capacity of 90-100 microfarads in parallel with the rectifier terminals.

The duration of the battery charging process depends on the voltage supplied by the bicycle generator, which, in turn, is determined by the strength of the wind. Since wind force is less convenient to determine than voltage, a small voltmeter with a scale of up to 10 V is mounted in the circuit.

V. POPOV