Or night duty (with reduced brightness) lighting, allowing at the same time significantly increase the lamp life, can be implemented in different ways. Among the simple and reliable method using a quenching capacitor in power supply circuit (Fig. 1). The capacitance C1 is calculated as reactance to obtain the desired lamp voltage ЕL1. Resistor R1 is necessary for capacitor discharge after disconnecting the circuitry from the network. Its value is in the range of 100-500 ohms.
Ham radio
LIKE THE PHONE
When connecting such a power source as an ordinary galvanic battery for flashlight, not so easy to achieve a reliable attachment of wires to flat pin made of thin sheet metal. Moreover, this procedure will have to be repeated when replacing a spent power cell. To simplify the operation and improve the contact will be Read more…
THE LAMP WILL SERVE LONGER
It is no secret that the halogen lamps used in cars, often fail. This is the result of inrush current, which inevitably occurs every time when enabled, when the spiral filament is still in the cold (cold) state.
THE MOTOR IN THE ROLE OF TESTER
Among the devices that are used to check (continuity) of electrical circuits, not take samples. They are simple in design and application. The probe is an indicator, in series with which is connected, as a rule, galvanic cell (battery), current-limiting resistance and two testers. Touching the probes on different portions of the circuit, checks the condition of all its parts and proper connections.
A SIMPLE “UNIVERSAL”
“Almost five years are a reader and subscriber of the journal “modelist-Konstruktor”. During this time, produced in any published developments in several homemade “for home, for family.” Would like to start welding-charging-starting device, a circuit diagram and description of which I had noticed in one of the rooms of the journal for this year, but deterred by the winding operation in the manufacture of powerful transformer, choke. And the installation of electronic control unit thyristors, I’m afraid not master. Whether it is at least a little to simplify the development of that interest me?”
WITH THE EFFECT OF “DISTORTION”
Amplifiers loved by many musical instrument — the electric guitar created a lot. Including the so-called effect of “distortion”, the essence of which is to limit the primary sine wave top and bottom, resulting in a large number of odd and even harmonics that give the sound of the solo guitar special melodiousness. About the original circuit solutions, allowing you to create in a home workshop good-quality amplifiers with the effect of “distortion”, repeatedly reported by its readers and “modelist-Konstruktor” (see, for example, No. 8’80, 2nd’88 magazine).
DISMANTLING THE SYRINGE!
Medical disposable syringes used for injections, thanks to the efforts of enthusiasts of technical creativity began to find further applications. For example, in Amateur practice, in particular during the dismantling of electronic components with printed circuit boards (especially in remote places where there is so often no “third hand”). However, the basic syringe has to be changed accordingly (modified).
GOOD TO BEEHIVE AND INCUBATOR
Applications I developed the thermostat is quite wide. It can be used, for example, to maintain the desired temperature in the vegetable stores, household incubators, in the hive. Combining simple designs with compact size and high efficiency design, this device differs from analogues of many well-known and even easy to use with built-in indicators on the LEDs.
HOME WIFI NETWORK FOR HD VIDEO
I recently made repairs in the apartment and decided to check if there is any chance at the current level of development of wireless equipment to create an apartment full of high-speed wireless network. Initially, the task seemed inappropriate (at home quite successfully, you can use Ethernet, why bother with WiFi?), but to convince myself that wireless technologies are not standing still, I decided to arrange a small test. One of the main criteria of success was the ability to view on a plasma panel HD-video rips with the volume from 10 to 30 GB in conditions when between file storage and replaying device is no wired network.
GAS LEAKAGE SENSOR
Explosions and fires resulting from gas leaks, unfortunately, are not uncommon. Recognizing the work of administrative bodies and emergency services, hams designers can do something yourself to minimize this danger. However, in the field of gas control is simple and accessible to a repetition of the device is almost there, or they are unnecessarily expensive.
There are industrial sensors, converts the gas concentration to voltage, current, resistance and other parameters. The ability to respond to changes in gas concentration have some oxides, especially the SnO2 — tin dioxide, doped various additives. On their basis it is possible to make an electronic device that responds to the excess concentration of a particular gas in air and emits sound signal.