(Continued. Beginning at No. 1′ 2005)
Instruments based on the radio. Modification of the receiver “VEF-Spidola”
The radio is a transistor superheterodyne (Fig.For the; scheme of the old GOST) and is designed to receive the stations in the bands long, medium and short waves. The receiver contains a mixer, separate local oscillator; three stages of the Ombudsman, the amplitude detector and uzch the complex except “spidoly” is universal prefix for testing semiconductor devices and the measurement (determination) of their basic parameters. Since the complex devices will be used in stationary conditions, power is supplied from a network source, is a separate external unit.
More precisely, one (50 or 65 watts), operating in three modes. Design advantages: constant availability, visual inspection of the three modes, etc. All provide automation. Power consumption in the idle — 15 watts (on L2), in the normal operating — 45 W (L2 and L3), and overheating — 50 W (L3). Changing modes 2 and 3 is made by the switch B1, in standby mode, by overlapping the luminous flux from L1 to K3 with the handle of the soldering iron.
(Continued. Beginning in №1,2,3 ‘2005)
(Continued. Beginning at No. 1,2,3,4′ 2005)
(The end. The beginning in № 4, 1976) the design quality
More lovers of mushrooms and berries prefer to reach remote treasured areas rich in forest, on their “steel horses”. Leaving the car somewhere under the lush foliage. any tree, fond of “quiet hunt” so much that sometimes lose orientation “in time and space.” And the result is the joy of communication with nature — a tedious search of the vehicle, left unattended.
In high quality stereorelease made on the basis of heads 0,25 GD-10-290 from small radios. Their advantages are a wide frequency range, small harmonic distortion comfortable ear cushions earpads, good isolation from extraneous noise and beautiful appearance.
Many years used the intercom system with loud-speaking simplex communication, consisting of a main panel and linear unit connected between a two-wire line. The radio was mounted low frequency amplifier. Here was the power source.
Any motorist knows that the state of charge of the battery must constantly monitor is required to control the pressure on it. This can be done by using electronic circuit which gives an alarm when low electrolyte level, high overload, contamination of the terminals of the battery, breakage of the drive belt of the generator, the overcharge of the battery.
In Amateur practice when developing or building a device often require multiple power sources at different voltages. For example, structures made in operational amplifiers and working in conjunction with digital integrated circuits require the bipolar and unipolar current sources. To use in such cases, the voltage divider is uncomfortable, especially in the process of developing new devices. After all, it is necessary to change the number of elements used and their type, which leads to a change of energy parameters of the device, and hence to necessity of the divider.