The diagram of detail of Fig.2 gives additional precise details: The signal HF collected by the antenna is amplified by T1, framed reel S of agreement L1 and L2. To vary the profit of T1, it is enough to vary its supply voltage. Here it passes from 4v to 0V, the varying profit of +10 dB with - 10 dB, is 20 dB on the whole. It is far from bebeing negligible! All the remainder of the assembly is integrated in a MC3362 from MOTOROLA. To notice quartz QZ1 ensuring the local oscillation of first mixer. Its frequency is of Freq/reçue- 10700 in kHz, so as to come out of the 10.7 MHz, filtered by a XF106 of KVG. Applied to second mixer with its quartz of 10245 kHz, we obtain from the 455 kHz, filtered by a traditional CFW455. The 455 kHz is treated in-house by an amplifier on 6 floors which supplies a discriminator FM granted by L4.
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This amplifier delivers at the same time a D.C. current proportional to the intensity of the received field. (RSSI). This current is amplified by T2 and T3 and allows the control of the profit of T1. You initially finds in fig. 1 the simplified diagram of the assembly. You see the HF amplifier T1, two mixers delivering one the 10.7 MHz, the other the 455 kHz then the saturated amplifier with the 455 kHz. Finally the FM demodulator and the output comparator which provides a rectangular signal to the logic of decoding. Let us note also the AGC chain with transistors T2 and T3 for gain control of T1 T1. The RX17-2 wants to be subminiature. For that purpose, we use quartz out of case HC45, without support. According to the manner of assembling it, the RX17 measurement either 27x32x23 mm or 32x38x16 mm. See photographs. In both cases, volume is of 19.5 Cm3 and the weight of 22 G, out of case aluminum of 6/10, without particular precaution. For these two versions, it is possible to come out the connectors, either with the square of the circuits, or in the prolongation. See photographs. This second provision makes it possible to have a receiver of 16mm overall thickness, which facilitates its installation in the narrowest cells. For this provision, an additional plate, envisaged in the layout of the circuit, is to be welded onto the line of the barbs " signal ". The junction being done only by the weldings, without plug wire....
This project fits more for custom made battery casing that can have more space to hide things inside. This switch with few alterations can be used for any other project as well but is designed based on e-bike needs! This project use a clever functionality of....
The circuit described here uses ultrasonic oscillations and operates based on the propagation velocity of these oscillations in the air. Thus, we can easily determine the distance of two points if the time within which the wave travels this distance is....
Sometimes the precious metals are hidden too deep and are not detected except with complicated devices. In many cases, however, small pieces of precious metal buried near the surface can be detected by relatively simple means. Everyone is very attractive to....
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The principle behind a metal detector is really very simple. Proof of this is the circuit that follows, in which it proves that the construction of a metal detector can be done in the minute, with few components that we find very easily everywhere. With the....
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In the past the sounding (sea bottom measurement) was done with the "bullet", that is, with a heavy lead object that the seamen plucked into the sea hung from a calibrated rope. As soon as the "bullet" reached the bottom, the depth appeared directly from the....
This Amplifier was designed to have the following specifications: Distortion less than 0.1% at full power of 100W even at 20KHz. Power has to be attributed to an extended bandwidth. The output transistors must be protected against short circuits. The power....
A series of LEDs serve to alert the gardener when plants need water. Using two conventional digital integrated LEDs and a series of LEDs, we make a very useful device for gardening. The device detects the amount of water in the pot and alerts the grower.....
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