Under the new rules of the road in the sake of safety, drivers of vehicles (especially when driving outside the city) should include the day of the lights But turn them off after a stop often forget If Parking is prolonged, the battery is badly discharged In chains prevent such troubles offer a simple device, which signals that the headlights were left on while the engine is stopped, and also indicates the inclusion of the turn signal Device contains a sound generator transistors (VT1, VT2) and a threshold of the relay (K1, VD1).
A SPRAY-JEWELER
Pulverizer offered ruts, Duplenko from the city of Ekibastuz, intended for painting models. Its advantages — simplicity of manufacture, reliability, the absence in the design of scarce materials and components. The device is clear from the figure. The tank for paint — small cans, pump — improvised (but not excluded the possibility of using a Read more…
The seeder is equipped with this opener, like a syringe: it can make seeds just under the soil, making a kind of “injection” at a given depth. This is due to the fact that swept the opener cuts into the layer of the earth, and through its tubular rack serves seeds, immediately cover the crumbling soil. However, the existing structure has one weak spot: the uneven distribution of seeds. Rows get thickened, and the aisle width of 20 cm is empty.
In most of our schools calls still include the old — fashioned way of push-button attendant or watchman. But this process is not difficult to automate. Proposed device designed for this purpose and may be made in the school radio. The block diagram of the device of the machine shown in figure 1. Electronic digital clock serves at a specified time in the actuator control signals. The actuator enables and disables the programming device, which, in turn, in accordance with the schedule of calls includes internal buzzer and external powerful school bell, feeding him the voltage is 220 V.
At first glance, the school gym is the same as thousands of others. But this is only at first glance… Observant person will note here something unusual. On boards and panels, attached to walls, installed button. Hanging above the light Board. The gym class begins with warm-up, and then the class is divided into groups. Students in one group with a small running start then jump at a time, hand hitting the button. While the scoreboard lights up every time the figure is estimation.
The Internet caught the eye diagram of the automatic charger Ni-Cd batteries developed by Yuri Bashkatov. Assembled the circuit on the breadboard — not working. Modeled it on the computer using the program Work Bench. The result is what is shown in the diagram. The device operates as follows. The transistor VT1 (p-n-p) is open if at its base there is a negative potential, which may appear when the VT2 transistor (NPN) open — this, in turn, occurs if the potential at its base is installed with the variable resistor R4 will be 0.3 — 0.4 V higher than on its emitter.
If during the day to measure the mains voltage, the voltmeter each time will be different. This is due to you can enable or disable individual power consumers, changing mode of operation (in accordance with the work schedule of production, process flow, etc.), that is, change the values of loads that cause instability of voltage in the networks.