The farm will always be radiokonstruktora old diodes and transistors become unnecessary from radios and televisions. In skilled hands it – wealth, which you can find a sensible use. For example, to make a semiconductor solar battery to power in field conditions transistor radio.
As you know, when illuminated with light semiconductor becomes a source of electrical current – photocell. This property we will use.
Current and the electromotive force of the solar cell depends on the semiconductor material, the magnitude of its surface and lighting. But to turn the diode or transistor cell, need to get to the semiconductor chip, and, more precisely, it should be open.
How to do it, tell a little later, but for now take a look at the table, which shows the parameters of homemade solar cells. All values obtained with a lamp power of 60 W at a distance of 170 mm, which roughly corresponds to the intensity of sunlight on a fine autumn day.
As the table shows, the energy generated by a solar cell, a very small, so they are combined in the battery. To increase the current, to give to the external circuit, the same solar cells connected in series. But the best results can be achieved with a mixed compound when photobatteries collected serially connected groups, each of which is composed of the same elements connected in parallel (Fig. 3).
Pretreated group diodes collected on the plate of Micarta, organic glass or PCB, for example, as shown in Figure 4. Between elements are connected by thin tinned copper wires. Conclusions appropriate to the crystal, it is better not to solder as the heat from the semiconductor chip can be damaged. Plate with photocell put in a robust housing with a transparent top cover. Both terminals soldered to the connector – it will connect to the cord from the radio.
Solar fotobatareya of 20 diodes KD202 (five groups of four parallel-connected solar cell) in the sun generates a voltage of 2.1 V at a current of 0.8 mA. This is enough to feed the radio on one or two transistors.
Now about how to turn diodes and transistors in photocells. Prepare a vise, side cutters, pliers, sharp knife, a small hammer, a soldering iron, tin-lead solder, PIC-60, rosin, tweezers, or tester ammeter on the battery and 50-300 mA at 4.5 V. The diodes D7, D226, D237 and others in similar cases disassemble so. First cut Bokorezy conclusions on lines A and B (Fig. 1).
Jammed with a tube in neatly flatten to make a conclusion G. Then diode clamp in a vise by the flange. Attach to the weld and a sharp knife, lightly hitting the back of the knife, remove the cover. Make sure that the blade of the knife is not held deep inside – otherwise you may damage the crystal. A clear conclusion from the paint – photocell ready.
Do diodes KD202 (and D214, D215, D242-D247) pliers bite off flange A (Fig. 2) and cut output B. As in the previous case, straighten crumpled tube B, free pigtail G.